Jeff Stallings, CPDT/KA

Littermate syndrome is a risk when raising sibling puppies

By Jeff Stallings, CPDT-KA

Many dog behaviorists, trainers and shelters discourage adopting littermate puppies because evidence suggests that behavioral problems may arise during key development periods. The two puppies’ deep bond may impede their ability to comprehend the nuances of human and canine communication, leading to hindered social skills and increased fearfulness, referred to as “littermate syndrome”.

Because fear is the default reaction to odd or unfamiliar stimuli in puppies, a muddled understanding of the world around the two littermates may lead to impaired coping mechanisms later on. Many factors influence behavior and not all siblings raised together will exhibit signs: Littermate syndrome is a risk, not a foregone conclusion.

littermate syndrome

Early Indicators of Littermate Syndrome

Signs include fearfulness of unfamiliar people, dogs and other novel stimuli (neophobia); intense anxiety when separated even briefly; and difficulty learning basic obedience skills. In some cases the two dogs fight incessantly. Over lunch recently, veterinarian and dog behaviorist Dr. Ian Dunbar and I discussed raising sibling dogs. 

“It’s a disaster waiting to happen for the littermates because they don’t get socialized to other dogs or people, let alone to their owners,” he said. Many owners assume their interacting with each other is adequate, “but when the puppies are five or six months old and meet an unfamiliar dog in a novel setting, they absolutely freak out.”

Dunbar points out that raising littermates necessitates training two puppies—particularly challenging when they essentially wear blinders to all but each other. “It’s more than twice the work; it’s exponential. The two combine to produce levels of energy that we can barely measure. Tension develops in training and compliance as they squeeze the owner out of the relationship. They’re always living with an enormous distraction—each other.”

Certified Applied Animal Behaviorist Patricia B. McConnell, PhD is also against taking in littermates: “They are so busy playing with each other (or squabbling), that you become the odd man out… It seems harder to get their attention, harder to teach them emotional control, and harder to teach them boundaries,” she says. “I have seen some nasty cases of bullying or outright aggression between dogs of the same litter, and it feels as though it is more common than between same-age dogs who come into the family from different litters.”

The tie that binds

Cohabitating siblings may become so emotionally dependent on each other that even short separations provoke extreme distress. Behavior specialist and author Nicole Wilde recalls a case in which two nine-year-old sibling Huskies attended her group class. “They were so bonded to each other that I literally could not take one and walk a few feet away to practice loose leash skills because the other would scream.”

Wilde believes the problems are rooted in hyper-attachment, leading to hindered social development and communication issues. “People assume that having two same-age pups that play together and interact constantly covers their dog-dog socialization needs, but they in fact don’t learn how other breeds play and have no idea about social skills with other puppies, adolescents or adult dogs. Perhaps one puppy is a bit of a bully, which his littermate puts up with, but his rude behavior might not be tolerated by a new dog in a new setting.”

Sometimes the most humane course is to re-home one of the siblings. Dunbar agrees that it’s often best to separate littermates, especially if symptoms appear early, so that each has a chance to develop normally as an individual. This is obviously a burdensome decision for the overwhelmed owner to make, a sort of canine Sophie’s Choice, so he recommends that the new owner meet both puppies and determine which to take home.

Together forever

Owners committed to raising a pair should ensure the puppies spend significant portions of every day apart so that each learns how to be alone—a key lesson in any well thought-out puppy program. This means feeding, walking and training separately, with individual crates in different parts of the home. Even trips to puppy socials and the vet should be separate so that both learn to incorporate these episodes into their psyches without being overly dependent on their littermate.

This separate-but-equal arrangement is time-consuming, exhausting and seems to defeat the original intent of acquiring siblings. Wilde notes that planned separations must begin immediately. “I’ve been called into homes where four-month-old siblings have been sleeping in the same crate for eight weeks and not purposefully separated by the owners, who had the best intentions but were unaware of littermate issues. Even getting the puppies to sleep in separate crates right next to each other is traumatic for them.”

Dunbar, too, is adamant that a key lesson for a puppy to master is how to be content with being alone, all but impossible with two siblings. “Once we’ve done that, yes, he can live with other dogs and have free run of the house. But if you don’t teach puppies early on how to be alone, and especially with siblings who have always been together, it will be catastrophic when one dies.” Dunbar encourages multiple dog households—“I always like having three dogs”—but the timing, temperament and age that each enters the home is paramount.

Most people contacting me through my blog never heard of littermate syndrome before finding the post while researching symptoms observed in their dogs. Increasingly, trainers and behavior professionals recognize that the cons of adopting siblings far outweigh the pros. “The only advantage I can think of is a short-term gain of the puppies being less lonely in the first month of life”, says Dunbar. “Everything else is a loss.”

Exceptions to littermate syndrome...and hope

While the majority of comments to my blog corroborate struggles in raising siblings—including the ongoing aggression and fighting often seen between same-gendered littermates—others write of well-adjusted cohabitating pairs. A common thread seems to be that littermates are more likely to thrive when introduced into a household with an older dog, who perhaps acts as an arbiter and stabilizing influence.

Myriad factors affect dog behavior, including genetics, early life experiences and owner engagement. As University of California/Davis veterinary behaviorist Dr. Melissa Bain points out, “two fearful littermates very well may be genetically predisposed to fear.” Bain is less inclined to apply the term syndrome to the set of symptoms: “It makes you think all littermates have problems, which is not the case.”

Bain also emphasizes that the level of owner involvement is key, saying “the symptoms escalate when the owners treat them as one dog with eight legs.” When conflict ensues within the pair, Bain believes it’s due to the dogs being too similar in size, age and gender. “This uniformity makes it difficult for the siblings to delineate a hierarchy,” she said.

Increased awareness of littermate syndrome

Recognition of the risks appears to be spreading, with many breeders and shelters declining to place siblings together. Shelley Smith, adoption center manager at Pets Unlimited in San Francisco [now the San Francisco SPCA], said her shelter stopped placing siblings together after a particularly disturbing case.

“A dachshund mix named Thelma was returned to the shelter because her sibling repeatedly attacked her and she had multiple injuries by the time the heartbroken family returned her to us. Thankfully we were able to re-home Thelma, but it’s almost certain the fighting and anxiety could have been avoided had the two littermates not been placed together. We now separate siblings and inform adopters about the rationale for our policy.”

While siblings blessed with extraordinary genes and socialization-forward owners may deflect littermate syndrome, the consensus among canine professionals is that it’s not worth the risk. Most would encourage new owners to adopt a single puppy that suits their lifestyle and to focus on the training and socialization that strengthens the interspecies bond unique to humans and dogs.

Once your puppy is a dog, by all means, get a second since the two will be at completely different stages, and the older one may very well emerge as a great life teacher to the younger.

[An update of this post was published in the Winter 2014 issue of Bark Magazine.]

381 Responses

  1. That was a brilliant article…..and of course whilst reading it, it all made sense.
    Never too old to learn something new!……thanks!.

    1. We had just the opposite happen with the two 10 month old Golden Retriever pups we adopted. They loved one another, kept one another company when we were out – played with us together when we were home – no rivalry – no sign of his syndrome you talk about. They were well adapted to people and dogs. Never had those problems. I had not heard of this happening until right now. Guess we were fortunate – they are both deceased now and miss them beyond words.

      1. Agreed. I had also never heard of this problem. We also had a wonderful experience adopting a brother and sister pair from our local humane society. They were border collie/lab mix and they were very easy-going toward people and other pets (cats or dogs). They did well until our girl got kidney disease at the age of 10. After she died our male dog adopted very well although he did seem to become more attached to me. He died about a year later. We miss them and after 3 years without a dog, we are considering adopting a pair of puppies again. But maybe not, after reading this article?

      2. We have always had success with littermates – and have always had two males, or a male and a female (never had 2 females – cause always wanted at least one male). We absolutely do not castrate the animals until they are at least 2 yrs old for all the very well publicized health reasons. They must be permitted to get through puberty for proper musculo-skeletal and brain development – not to mention immune health and for all the body’s systems. I left one male whole this time for specific reasons and absolutely no problems. In fact, the neutered male is the supreme alpha. They love each other unreservedly and us. They respect my husband as the pack leader and me as the pack top Bitch. They are perfectly trained and obedient. 3 yrs and 3 months and there have been only 3 actual fights (barring play wrestling) which were extinguished immediately. One over my attention, one over a toy and one where the alpha got tired of his runt brother. They separate just fine if with me or my husband. There is a little moodiness if left with my daughter – where they will sit by the door waiting for either me or my husband to return for them. But, we just have not had the troubles others have posted.

        As for Patricia — your 2 females have fought so few times in the period in question. Even in the best of family dynamics – children fight. Time-outs are usually all that is required, followed by reintroducing with lots of positive reinforcements to both dogs.

        Sorry so many people have not had good luck. We took on a 3rd of same breed – white shepherd pup rescue whom the 2 three-yr olds cut a lot of slack. He is the maniac. They all act like brothers now – and while the pup is coming along — he play attacks incessantly the 2 older dogs. The alpha fends him off without major controversy – but the runt gets it in spades. He hasn’t been able to fend him off, nor does he always want to – so we have to intervene and separate, just like with obstreperous boys. I am hopeful that in time this will die down – as my 2 older ones simmered down with age. We already love the new boy – but he is a handful.

        Littermates require extra ‘awareness’ so as not to fall into the traps as outlined by Jeff’s articles. Is not for everyone, but, it certainly can be wonderfully done. Dr H


    2. I have two standard poodle littermates I brought home at 6 weeks. they love everyone and everything never any problem. One is alpha . they are more like friends one is good at some things the other is good at other things. They do things by their selves and together. They like to play basketball in the street with neighbor boys. Yes on different teams LOL

  2. I am currently experiencing this “Littermate Syndrome” with my 15 month old lab/terrier females. We were completely unaware that such a thing existed and the people at the shelter from which we adopted them mentioned nothing of the such. They actually encouraged us to adopt both puppies. The aggression towards one another just started about a week ago and it is awful. I am heart broken at the thought of having to re-home one of them. Is there any way that they will grow out of trying to over-dominate the other and can eventually live in peace with one another again? Or should we absolutely re-home one of them?

    1. Kirsti, I am sorry to hear that. What age were they when you adopted them? I am not sure where you live, but I suggest working with a behavior consultant/trainer to help evaluate all your options.

    2. Hi. I have two mini Aussie sisters who faught like crazy. I would step in and separate them. Like Cesar says: “Be the pack leader!” I made it very clear I’m the boss, and they have settled down, loving each other. I do separate them, and do a lot of one on one training and take them to dog parks. I also do long walks, runs with them before I try training them. They love people, will tolerate (but don’t play with) other dogs. That is really the only issue I have with them right now. Socializing is key. A pro. is always best, but there is hope if u are willing to put in a lot of time! Good luck.

    3. Kirsti. I am not a professional, but will share my experience of having 4 sisters from the same litter; a litter that my partner and I raised. We went through this with them; expecially with the aggresion issue. Even more horrific was that fact that 3 would gang up on the same 1 everytime. No matter who a fight started between; they all ended up ganging up on the same sister. I was shocked, I had never seen this before and as a former registered AKC Cardigan Welsh Corgi breeder I never experienced this, and I did have 3 litter mates from the same litter through adulthood. There was even an instance when all 4 ganged up on their mother; which only happened once and they knew better after that. Part of my girls problems are they are not spayed; and female dogs do become aggresive when they are in heat or when another female is in heat. We currently have 7 Basset Hounds; our 7 yr old, her 4 daughters, a male not related and a 5 month old offspring of one of the daughters and our male. We were at a point where we were going to re-home 3 of the sisters, but we just couldn’t decide. We raised all four from birth and adored something different about each and every one of them. We were in fear that the one would get seriously injured. Well we decided at 2 years old we were going to start treating them like dogs. In other words if you treat your dog like a human they will treat you like a dog; so the re-training began. It took 2 more years and them all having a litter of puppies to get it. I don’t know how you have raised your siblings, but know this, more than 1 dog makes a pack and the pack mentality is what they understand. And every dog in every breed is different. My Welsh Corgis at 4 weeks old did not fight like my Basset Hound puppies. I have had 5 litters since 2011; every whelping was different; every mother was different and every litter was different. Nothing is textbook when it comes to dogs; there are too many variables to take into consideration to say this is what “you'” should do. You know your dogs better than anyone and it just takes perserverinence and a strong resolve, but it can be done. My partner and I are alpha and beta of the pack and now their behavoir has made a complete 360…They may still growl at each other over something, but if we are there that is as far as it goes. We know who we can put together while we are working and feel confident that we will come home to no injured or even worse. No more than 2 together in the same area of the house; when it comes to the sisters being in the yard together; we must always pay attention and know who can be out with who. The one that was getting ganged up on; refuses to go out with the one sister and will never go out if the other 3 are out; problem solved. She is now on the offense and basically growls at any of the others when they come near her, but we are there to defuse any situation; retraing was much more work, but definately worth it; we still have our family together. Talk to your veternarian, about the issue and see if there is something they can recommend resides re-homing that may help. Every behavioralist I contacted said we “must” re-home 3 of the sisters. We got to a point where we did look at it in a human way. If we had 4 children and they fought; would we discipline them to correct it or just re-home 3 of them. The answer is obvious; besides it is illegal now in most states to re-home your children. Good Luck!!! and have patience and be firm with them.

  3. My husband and I made a huge mistake and purchased two male littermates at the same time. They are now six months old and one of them (Boo) is continually fighting with the other(Bear). Bear is now cowering down when he sees Boo coming toward him. We also have a five year old (Max). These are all German Shepherds. Max has been circling Bear every time Boo comes near. Max is very well trained but is now exhibiting tremendous anxiety. A lot of the time he will not even eat and neither will Bear. I have tried to find a home to no avail and have talked to three trainers about this and all said the same thing—not good at all. Bear had been very playful and confident but doesn’t seem that way now and Max is worn out trying to keep them apart. We cannot separate them due to housing and time issues. We are at wits end. I have put a call in to our local State Police because I was told that sometimes they will take a dog to train for their canine unit. I haven’t heard anything yet. We had never heard of Littermate Syndrome until talking to the trainers. This is horrible! Any suggestions?

    1. Yours is unfortunately a classic case. Definitely rehome one of these dogs. I would lean towards keeping Bear since Boo might have a bit more confidence to draw on. You are going to have to spend lots of time working to rebuild Bear’s confidence.

      1. We just recently re-homed one of our Siberian huskies. We got a brother and sister from a breeder. They have been together since birth and are now 2 years old. They both interacted with other dogs on many occasions but the male was extremely dominated over his sister and we felt it best to separate them. I like others didn’t even know this would be an issue. Its been almost two weeks now and Sapphire, the sister that we kept, has started to lose her appetite and has started to whine/cry/bark much more when left alone. She is still very excited and energetic at play time but the eating has me a bit concerned. What can I do to make this transition easier on her?

    2. I wouldn’t rehome them. If anything get crates…keep them crated when noone is home. Then when you are there give them lots of exercise and immediately correct poor behavior. It takes vigilance, consistency , patience and exercise! Hope u kept your dog.

  4. We adopted 5 yr old beagles who are littermates. We also did not know of the littermate syndrome before the adoption. Is this an ethical hot button in the breeding and adopting communities? What can be done to get the message out better?

    1. Bonnie, I am researching this topic and have met with veterinarian behaviorists at UC Davis. I will be interviewing Dr. Ian Dunbar in the coming. I am writing an article on the subject with the target of publication in a national magazine, such as The Bark. I would be interested in talking to you about your experiences.

      1. I am not sure I will be able to add a whole lot to the discussion, but I am willing. How can we set up a contact? (I’m using my fb account this time; the other is a shared account.)

  5. We adopted two chiapoo puppies. They were 9 weeks old. We originally intended on getting just one but the original owner said we could have both as he needed to get rid of them by the weekend(going on vacation). We quickly saw some aggression. One pup more than the other. They were the center of each others world and got aggitated whenever one of us interrupted their play. We thought it best to sell one. But after seeing your blog, We really started to push the sale. The pups are 12 weeks now and really feel like they need to be separated to be good family pets. Thanks for this article.

    1. You’re welcome. I am working on an article about this subject for Bark Magazine right now, hopefully to get the word out so fewer people head down this often-disasterous path.

      1. When your article is published, will you have a way that other trainers can print it to reference it or hand it out? I see people getting litter mates all the time coming into the store that I am a trainer in. I also have people that ask about it and I think having an article/handout ready and waiting to give to people to take home and read would be helpful in spreading the word. The more that people know the better.

        When I was a pet sitter I had litter mate labs (male/female) and right around one year, I had an incident with them where one became over stimulated after I brought her away from a very “playful” snake and she then started biting at me and while trying to calm her the other joined in. Even though I recommended that they take the pups to training when they were younger, they never did (even after the incident they didn’t take them to training).

        Of course I found out later that the female wasn’t allowed out with the boys because she would get over stimulated and go after them and their friends. I ended up firing them as clients.

        1. Thanks for your story and perspective. I am waiting for my interviewees to approve the draft, then it will be up to the magazine (submitting it to three) as to when to print. Feel free to print this article out to hand to folks!

  6. Excellent article!! It is very true that breeders and rescue shelter groups are encouraging people to adopt two puppies in a litter because they are apparently unaware of this. I had a client that called me that had two foster puppies from the same litter. They experienced severe aggression between the two at less than three months of age. I advise them to take the other puppy back to the rescue group and keep just the one. He’s turned into a wonderful puppy through their socialization and obedience class work.

    Nan Wells
    DogWoods Retreat

    1. Not all breeders encourage people to buy/adopt two puppies from a litter! I am a breeder and will not let buyers have more than one puppy for the very reasons stated in the article. Reputable breeders won’t let two puppies go to the same home and I certainly will not encourage it to “get rid” (I hate that term, it sounds like the puppies are rubbish that needs discarding) of puppies for any reason.

      1. Leanne, I take issue with your comment that “reputable breeders won’t let two puppies go to the same home”. I AM a very reputable, responsible breeder and I have in 2 instances over the years, allowed the same family to adopt sibling puppies. Just because you don’t do it, doesn’t mean that others aren’t qualified enough to interview and know well enough that the family they are allowing to adopt is capable of properly socializing multiple puppies at once. I don;t allow it on a regular basis, but in both instances these were large families with 4 or more older children that were both committed to making sure the puppies were socialized separately so they didn’t become too dependent upon each other. In both cases, they ended up being incredible, well behaved family companions. The world is not black and white, so don’t make such close minded, offensive statements.

      2. I agree with Leanne, I am a breeder and do not place two puppies in the same home at the same time. I never “get rid” of puppies, I feel that I am responsible for the puppies I breed, and if they don’t get placed, they stay with me. I also volunteer with a rescue group, we very, very rarely place two dogs at one time unless they come to us as a bonded pair. Get one dog socialized to your home and lifestyle and then add another if you wish.

      3. Well I sure wish I went to you! I looked forever for a Male Min. Pin since my boy passed the previous year. At the time my girl Min Pin was a Senior & we all missed another playmate. Well COVID hit when I bought & i could not pick up my boy from Breeder until 15 weeks, & by then my girl had passed &breeder said maybe it’s fate, there is 1 female left in liter with yours do your want to take both? As she knew my ultimate goal was another boy & girl, they were great! Well these guys are hell on wheals. I cannot take one pee with other screaming or if someone walks up god forbid & just talks to the girl he will panic & he will excessively bark & loose control. I have done a week full day classes for both, have totally separated sleeping, food bowls, but he still will bark if he can see her through playpen, but cannot touch her! Now the fighting is getting under control. I wanted to try One more week of taking turns each day bring one to a ‘stay & play’ for 1/2 day so they go have fun & maybe they will see how much they love. i pray it works…will be very hard to pick which one will move on. Whomever is questioning if this syndrome exists.

  7. I rescued 2 female Jack Russell mix litter mates 10 years ago. I really wish someone had told me then not to adopt both of them. I love both of my girls dearly but having them has definitely been a trial through the years. I’ll be honest and say I don’t think I have many of the syndromes problems, but I do have my fair share. They are both food aggressive especially with each other & that is what usually causes their fights. And good lord when they fight!!! There is ALWAYS wounds after their fights. Some have been bad enough that I’ve had to take them to the vet for stitches and deep cleaning of puncture wounds. My girls aren’t big (both about 30 lbs), but when they’re fighting it can take me up to 15 mins to break them apart. They are both very strong & focus so much on fighting that they don’t even realize I’m there. I’ve been bit a couple times while trying to break up the fights but thankfully nothing a good cleaning and a bandage couldn’t fix.

    I volunteer with a rescue organization now and often tell people NOT to get litter mates. Then I go into some of the stories I have about what I’ve gone through. I will absolutely never make that mistake again but at this point in their lives I won’t rehome either one. I couldn’t do that to them…or myself. I know that I’m fortunate that for the most part they tend to get along and play well together. But I will never never never have litter mates EVER again. I do want to thank you for this article as it finally validates what I’ve been saying for years…NO LITTER MATES EVER!!

    1. Hello Kristin, thanks for your contribution to the subject and for helping to confirm that this condition is real, common and, ultimately, avoidable. I would never suggest that you separate them after this many years together. Lots of management, as you well know.

      This blog post has become a de facto source of information, apparently. Hits to this particular post have increased exponentially each month it’s been up. To that end, and to get the word out, I am working on an expanded article, hopefully destined for print in a national magazine so that more people are aware.

      By the way, your symptoms are classic, in particular, the fighting. That is not normal and such in-home brutality is rare…except among littermates, and especially same-gendered ones.

  8. About 14 years ago I brought home a lab mix puppy and then a week later I brought home her litter mate. Both females, lab and german shepard mix from an ‘oops’ mating. They had a great relationship, bonded well with their humans and were great pets. As puppies they were boredom chewers but that was about all. One passed away two years ago of cancer and the other is riding out her final years. They never exhibited aggression or any poor behaviors. At the time I had siblings that were 2 and 4 and they were also great with the kids. I now have two smaller high energy rescue dogs and the old lady is great with them as well. I guess we were SUPER lucky!!

    1. There are definitely exceptions! The siblings from different litters would not fall into this category, by the way, since they were/are at different developmental stages.

      1. There are most definitely exceptions. I took on two brothers who at 3 months were dumped on a motorway (I live in Cyprus so this is not uncommon unfortunately). They have always had quite different personalities, but I think the reason we never had any problems is because I am so terribly bossy. I was aware we could have a problem but we decided to give it a try and they are quite perfect. Do lots of tricks and their recall is amazing (I taught them to return to a whistle). One always seemed quite happy to be the underdog, but the difference was not obviously to anyone but myself and my husband. They are as well “submissive” types so probably this has helped. They are extremely close, friends call them bookends but we have even parted them for a couple of hours when I took one to the vets. My husband stayed with the other one, and they were both fine. So perhaps we have been very lucky.

    2. Thank you for posting your response. Johanna. I, too, somehow lucked out with my two 12 year old Husky/Dalmatian sisters (also an oops, I am assuming, as they were found in a dumpster at 8 wks, when I promptly adopted them). They rarely fight, and when they do, it is over as quickly as it begins. With what I’ve seen out there among litter mates, Mr. Stalling’s article is on the money. Johanna, you and I can count our blessings!

      The reason I want to thank you for your response is that I have the biggest fear that when one passes, the other will not be able to cope. The fact that you lost one two years ago (my sincerest condolences) yet the sister has thrived for since is soothing to me. I really needed to read that; thank you for giving me hope.

  9. Hi
    Sorry that your going through this with your pets. I was not aware of any of this. Hhowever i have to say that my neice adopted brother sister litter mates. They have had no problems except with mischief. Sister can be , but not always protective of her brother. They even go to dog parks and do very well. As far as bonding to their humans. With these two they love everyone. So happy story here but it sounds like its an exception to the rule.

  10. Hi!
    We have been raising litter mates together for forty years. We have never experienced any of these problems. Seems these are problems of dog owners failing to maintain control of their dogs through training and less of raising litter mates together.


    1. There are definitely genetic and training issue that can lead to this problem. It sounds like you are on top of both, so that’s great. But this is a real set of symptoms in many littermates. Read some of the other responses below. I delve into this more and interview behavior experts in an upcoming print expansion of this article. Thanks for your perspective, it is appreciated.

    2. Definitely agree, Deb. We have sibling standard poodles that were 3 in Jan and have had no issues. It is wise to spend quality time separately with each, but why wouldn’t you. Once one understands that “puppy class” is for owners, most of the rest is common sense.

    3. As with having any dog, you get what you put into them. If you take the time to train and work with them you get wonderful dogs. I have bred dogs for years and right now have 2 sets of dogs from 2 separate litters. I walk them separately, train them separately and put in time with each one. As with ALL dogs you need to spend time with them and work with them. If you just leave them alone and do not spend time with them, yes you will have problems. But that will occur in any dog that is not socialized and trained. Siblings are not the problem the owners are. My dogs have been Obedience dogs, Therapy dogs, conformation dogs. Do not keep 2 dogs if you are not going to have the time to spend with them.

      1. It is too bad that you base your conclusions solely on your experiences and are so closed-minded to others’ experiences. I am thankful I was raised to listen and learn from other people and the experiences they have gone through. Currently, I own 2 doberman puppies. I have owned dobermans before and also have an older Great Dane. The puppies have started to exhibit the symptoms of littermate syndrome despite my efforts to individually train, socialize, and bond with each. I’m happy that you haven’t had to experience this, but I can assure you that your reasoning and blaming are completely misplaced. They say ignorance is bliss… I am quite sure after reading the ignorance that you spew, that you, Deb, are blissfully happy.

    4. I am raising litter mates right now. 2 Lhasa Apso Brothers. They are 8 months and a joy to be with.. They are social with other dogs, Love people and have been very trainable. They both give my wife and I a whole lot of attention. They do fight every now and then but it is getting better. They work things out. For instance they know whos food is who’s, they know if the other one doesn’t want him to have a toy. But they may also play togeather with that same toy at other times… I can see someone that wants a pet that wants everything nicey nice all the time may not be able to handle siblings.. So what am saying this is not a black and white thing. And should not be treated s such.. Look at your family, do you spat a little, do you love a little, do you miss your siblings some times… Did your kids misbehave some times… Anyway I would not have it any other way… Both theses dogs are the best I ever had.. Thye are rock stars.. Buddie Holly and Elvis Presley…

  11. I guess we got extremely lucky. We have two shep x littermates, both very very bonded, love each other, love us more and are the most social and affectionate dogs you’ll ever meet. They are sweet to everybody. They’ve never had a fight, are great with food and toys, love to chase but don’t get aggressive. They do compete for attention for sure, but never in an aggressive or harsh way. And we have a challenge with jumping on guests because they’re excited, but that’s as bad as it gets. They will be two in April, and have never had a fight or even exchanged harsh “words”. I’m knocking on wood as I type this….but so far, its the best decision we’ve ever made. I also have friends who adopted littermates a few years back, and they get along well too.

    1. This is not universal among all co-homed siblings. However, it occurs frequently enough. I mostly want people to be aware of it, to avoid adopting siblings if possible (there are other reasons to just have one puppy at a time), and to know what to look for. It sounds like you have an awesome set of lucky dogs!

  12. I heard of this syndrome only after I adopted two female border collies at approximately 6/7 months of age (they are now about 11 months). They were found together and were assumed to be of the same age and litter. I adopted them separately but within about 6 weeks of each other. We brought them into a home with an 11 y/o male border collie we have had since he was 1 and a half years old. After a little bit of adjustment and my male bc assuring one of the girls that he was Alpha, the issues have subsided. They all play fairly well together or one-on-one but occasionally it gets a little out of hand and there is growling and mouthing but so far no blood. A squirt of water and separating usually does the trick. My question is, if we are fortunate enough to not have a problem by the time they are out of the puppy stage and are sufficiently socialized, what is the likely-hood that we are in the clear? We love these pups and I dread the thought that I would have to rehome one of them.

    1. It sounds like your male may be a stabilizing force, so I wouldn’t think you have to worry about having to re-home one. You didn’t have them during the socialization period (up to about 16 weeks) so it’s impossible to know what sort of exposure they had to people and dogs. I would suggest that our spend time with each of the siblings one-on-one, focusing on separate training sessions with each.

  13. I believe it has more to do with trying to raise two puppies at one time. The same as any two children at oane tiem. it is far more difficult.It isnt impossible ant there are positive as wellas negative effects. But Two puppies at once can never getas much attention as one at a time

    1. You got the “far more difficult” part right. Notice I said in the article that it can be done, but to do it right requires separate crates in separate rooms, separate training, feeding, walks, socialization, trips to the vet, etc. I was talking to renown dog trainer/veterinarian Dr. Ian Dunbar about this recently and he agreed strongly that there are no good reasons to do this. Yes, they may both turn out to be confident, well-adjusted dogs. But they may also be emotionally damaged for life. My point is, it’s not worth the risk.

  14. Interesting article and as a breeder I would not allow 2 to go to the same home, however I am keeping 2 from my current litter so will certainly watch out for these signs. However I would not take by babies out socialising until they are fully vaccinated at 12 weeks old

    1. Waiting until after the 3rd set of shots is not in the interest of your puppies! Indoor puppy socials with non-littermates is the most important thing you can do, starting after the first set of shots plus 7 days. Breeders and new owners are doing a great disservice to these animals by waiting until AFTER the primary socialization period to introduce their puppies to the world. The chances of raising a dog with severe behavior problems far outweighs the chances of contracting Canine Parvovirus. They absolutely should be kept away from porous surfaces, including dog parks and beaches. But indoor puppy socials and meeting 100 people before 12 weeks old is imperative.

      The American Veterinary Society of Animal Behavior (AVSAB) concurs with this practice. Their official statement on the subject reads:

      The primarily and most important time for puppy socialization is the first three months of life. During this time puppies should be exposed to as many new people, animals, stimuli and environments as can be achieved safely and without causing over-stimulation manifested as excessive fear, withdrawal or avoidance behavior. For this reason, the American Veterinary Society of Animal Behavior believes that it should be the standard of care for puppies to receive such socialization before they are fully vaccinated.

      1. Have you been through parvo treatment and the heartbreak of losing puppies? I have, not fun. A good breeder does puppy socialization with many different people, offers various stimuli, etc. To risk the health of a puppy with only one parvo shot just to socialize with other dogs is not a risk I would take or recommend. Been there, done that.

        1. I have seen parvo. You’re right: it’s horrible. I also work in shelters with dogs with extreme fear because they weren’t properly exposed to other puppies and to people before 12/16 weeks of age. Many are needlessly extremely emotionally damaged. You can socialize your puppy very little risk of parvo if you’re smart about it. I attended a symposium on the subject at the University of California/Davis last weekend, a room full of veterinarians and veterinarian behaviorists. Conclusion: The risk of a dog being euthanized due to behavior issues resulting from a lack of early socialization is orders of magnitude higher than contracting parvo. This is not MY view; it is the official view of the most knowledgeable scientist in the field. The American Veterinary Society of Animal Behavior (AVSAB) official statement on the subject:

          “The primarily and most important time for puppy socialization is the first three months of life. During this time puppies should be exposed to as many new people, animals, stimuli and environments as can be achieved safely and without causing over-stimulation manifested as excessive fear, withdrawal or avoidance behavior. For this reason, the American Veterinary Society of Animal Behavior believes that it should be the standard of care for puppies to receive such socialization before they are fully vaccinated.”

      2. Yay!! That old-school ‘wait until all vaccines to socialize’ myth is WAAY off mark! JT, get ’em out NOW (but separated!)

  15. This looks like a really good argument in favor of the very early socialization protocol – handling puppies and exposing them to minute amounts of stress starting a few days after birth. There are breeders out there doing this, and describe the differences in confidence and adjustment to the human environment as nothing short of amazing. I’m very excited to read your expanded post!

  16. I will attest to what you are saying. I adopted out 2 boxer mix puppies, male and female. They came back to me at a year of age because they were so aggressive to people. Those 2 dogs attacked any animal in their paths. I kept them in fear of them hurting any other animal in someone else’ care. About a year ago, I had to give up my rescue and was terrified about these dogs. An amazing rescue took them and after being together for 8 years, they separated them. Those 2 dogs live amazing lives…..with other animals!! The two together were NOT a good idea, even though they were so bonded. It about caused them to lose their lives too soon. I also had a father son combo. The son was terrified of people. The puppy at over a year old got tick paralysis, and I had to take the puppy from the dad… thing that ever happened to that dog! He came out of his shell and is the most amazing dog! Thank you for your article.

  17. I raised 4 littermates, I had them since birth because I am their breeder, I did all the things you said, take them separately to the vet, to training classes, walks etc. They do not have littermate syndrome, they are 6 years old now, I still take them for separate walks etc. It really wasn’t all that difficult to raise them that way, but then I was aware of it from the start and did things accordingly.

    1. Exactly. You allowed them to develop individual identities with the separate walks, training, etc. Littermate syndrome is not a foregone conclusion, but if you have siblings, you have to be diligent as you were to avoid it. Kudos!

  18. Reblogged this on Payfer Pack and commented:
    Here is a great post, with an expanded article to come, by Jeff Stallings, CPDT-KA about why raising litter-mates is not in anyone’s best interest. While it can be done, if done properly, it is a lot more work and two puppies will not receive as much attention as one puppy would and to do it right, you need a lot of extra time and money. Thank you Jeff for writing such a great article! I will do my best to help spread it around.

  19. As a breeder I completely agree with your comments on homing siblings or puppies of a similar age together. I think a gap of about 12 – 18 months or later is acceptable. Having said that, I recently kept two pups (both bitches) from the same litter. I made a tremendous effort up to about 4 / 5 months to separate them during the day. My usual routine was to send one of the pups to day-care and have one with me (I work from home). The one pup was a little more timid but having said that both have blossomed. They both are shown. They can be shown in the same class and focus on their handler, they can also go to a show alone without a problem. My only concern is that they play very very rough! I have never seen anything that would make me think that this could escalate to a fight but realise this is not impossible. They are now 18 months old. They also differ quite a bit in temperament. The one is a very outgoing girl and will go and play with everyone on the beach; the other is also playful but does not wonder off to play with other people on the beach but prefers to stay with us. The one is quite vocal, the other hardly ever barks, the one is destructive (will destroy toys or shoes if she gets a chance) the other doesn’t and the one will jump our fences the other won’t. BTW these are Golden Retrievers. Also I have a few adult dogs to which they are exposed to all the time. I think this also helps with what is acceptable behaviour and what not. Would love your comments about whether you think there might problems with them in future or do you think that we are on the right track?

    1. You did all the right things as far as allowing each to spend time without the other. That is key. If you can do that, you’ll probably raise confident dogs okay on their own. It’s impossible to say whether problems will develop as they reach social maturity (about 3 years). Just keep focusing on having them be together sometimes and apart others.

  20. We have 2 brothers that are beagles and both of them have done well with other dogs and humans. They are best friends with each other.

  21. We have kept 3 sets of siblings over the years, with no issues whatsoever. Temperament of the dogs and common sense of the owners plays a big part in how the dogs mature into adults. We have also also had several adults with the puppies which teaches them how to be acceptable members of the pack.

  22. We used the “very early socialization protocol” on our litter of 6 pups 4 years ago. We did not let puppies go to their new homes until fully socialized at 12 weeks. We kept one pup. We have recently gotten one of the pups back due to a family problem and noticed that although the dog received no formal training, he is well mannered, sociable, gets along well with his littermate who is here, re-integrated with no fuss or bother and has no fears or phobias (i.e., fireworks, vacuums, etc). The owners of the rest of the pups attest to their stable temperaments.

    1. Do you have a link or document on what protocol you used? Would love to share it with puppy foster parents- the more well-socialized dogs we have out there, the better! Thanks

  23. We rescued two female shep X’s and were told from the very start to watch out for the hyper bonding. They are now almost 4 years old and I can I can honestly say we really have not had any issues. We have had the occasional, though very rare fight, they play well together and love other dogs. They are very affectionate with us (one is almost too loving!) the biggest problem we had was teaching them their names (though once we got some advice we solved that in one afternoon with a whole lot of treats!) I find they are no more upset to be apart then my past dogs who were not siblings. Overall it has been a great experience though I would not do it again because it is a lot if work (though I still believe that dogs should always have a friend) early socialization was the key I believe.

  24. We have 2 lab mix littermates that we adopted 3 years ago when they were 4 months old. We had never heard of nor did anyone ever tell us about Littermated Syndrome. In fact, the rescue we adopted them from was so thrilled that we were keeping them together. As a result we did everything with them together (from crating to training to vet visits and so on). I will admit that sometimes they function as “one unit” but they are very well socialized and each has her own individual personality. I will however take a page from your book and begin working them separately. Hopefully it’s not too late! Thank you for a very interesting and informative article.

  25. This text was an eye-opener, everything now makes much more sense and I think I finally got an answer to question I’ve been asking myself for more then two years: “Why is my dog like that?”

    I must say my experience …. I got a female Dobermann puppy at age of almost 7 months, which stayed with her breeder until that time … She had one litter-mate staying there with her and other dogs similar to her age … I know for sure that they were always together, meaning breeder didn’t feed them separately, take them to walk separately etc …
    When I got her, I experience the most disturbing dog personality I have ever ever encounter. Such amount of fear was unbelievable! And it wasn’t a fear that she would easily shake off or get used to quick…. It was so intense and so irrational, completely without any logical understanding or explanation. She feared everything that was around her, inside and outside of house. Passing through doors, stairways, bags, bushes, trash cans, traffic signs, not to mention people, dog, traffic or noises, she feared going outside when it’s dark, or passing over bridges, under highpasses etc … everything! To her I was OK, but I with a cup in my hand was not. It was the most horrible experience of my life. And every time I talked to her breeder, she told me that in her pack she was just fine, not scared and being even bold and outgoing! The breeder thought it was my fault …
    I struggled with her for many months, thought that she is just poor socialized and spent up to five-six hours every day (before and after a full-time job) to get her accustom on as much as possible things that was going outside, and also inside, and after couple of months of endless hours spent with her, I finally get to see glimpse of improvement. We continued hard work, and socialization and education, and now with her being almost 3 years old, I can say she is doing much better, most of the time you can’t even say she is fearful or shy or was anything like before. She has well manners and is very obedient, has very strong bond with me, and is very much loving to anyone she knows, dog or human. But is still shy to most strangers, especially the ones we meet outside, very rarely allows strangers to pet her, and doesn’t like to play much with dogs, only ones she knows; and also it takes much longer to get her used to new situations or items … Like she was fine with metal crate in the house, but it took me three weeks to get her accustom to plastic crate inside a car, and also I’m trying to get her accustom to dog trailer (for my bike) but very very slowly, so it’s taking now more then couple of months …. So, in the end, thankfully we worked it out somehow, she is manageable and loving, but I know she will always be “my special one”, and I’ve except her as she is.

    Thank you for this article,

  26. I have adopted a brother and sister from the same litter twice. First, a pair of Jack Russell/Beagle mix and then a pair of Dobermans. I haven’t seen these extremes in my pairs and we were always pleased about having a pair so they weren’t alone. Now I have one old Doberman and a Mini Dachshund. We adopted the pairs at 8 weeks. The only aggression was between the girls and boys of the different breeds. It always seemed to be the Alpha battle.

  27. It’s funny that most of the responses completely agree with the author. I have three litter mates, 2 boys and a girl, and not only was it not hard to socialize them with other dogs, or take them to the vet at different times, it’s also quite easy to feed them in their crates and play and work with them or walk them individually at different times. None of my three show any of the “syndrome” mentioned in the article. I think the article is very one-sided as it doesn’t cover what may have happened during the important time period when puppies get introduced to strangers and strange noises, a time when they are within their litter protected by Mom. By the time my pups went to their homes, they were used to normal household noises and had seen plenty of other humans as well as a couple of other dogs. Even with my three now, I do not have any of the listed problems aside from normal age appropriate squabbles.

    1. I am sorry you find the article one-sided. In fact, you mention the manner in which you worked with your dogs (walked, crated, played and train separately) is exactly what I recommend for siblings in the article. This absolutely is a socialization issue, with the siblings not properly introduced to strangers, other puppies, noises, bicycles, cars, buses, children, etc before 12 – 16 weeks because of the hyper focus on each other. Also, as for the alleged one-sidedness, I do state that there are exceptions. I don’t have the resources to do a bona fide study. The upcoming print version of this article expands on this a great deal, and I interviewed Dr. Ian Dunbar and renown behaviorist Nicole Wilde as well, both of whom have dealt with numerous tragic cases. So, just because you took the appropriate steps to individually socialize and train your siblings doesn’t mean everyone else knows to do that, or even how. That is the purpose of the article!

  28. I have two rescues from the same litter who exhibit none of these problems. They have only been separated from each other one time, the day they were both neutered. From the time I got them I socialized them heavily with other dogs, people, and other animals. They’re now over two years old and are some of the best behaved and socialized dogs I’ve ever had.

  29. I am a breeder and have experienced this when running on two bitches. Invariably one would turn out ok and one would not want to hook on and work properly with me, the one not hooking on was always desperate to scale authority in the pack, not just with the sibling, so I feel its an alpha issue. Always trained and fed separately, taken for drives seperately, seperate shows etc. Never had a problem running on a promising bitch and dog from a litter… but again a lot LOT of work of separate training and social activities. I am lucky my extended canine family are all obedience trained and help to pull young dogs in line, we work as a pack, Running on siblings is not easy and I fully dont recommend it to the average dog owner. Lots of sweat and tears.

  30. My personal experience is quite the opposite. I’ve have/had two sets of female litter mate Mastiffs, and at the same time. No problems at all! They always had someone their own age/size to play with. Just need to always treat them equally. I learned to use there names first on commands and reprimands.

    I pretty much violated all the rules you list. They were raised together. Fed together (separate bowls). Slept together. Went on outings and to the vet together. I do spend some individual time, but mostly we do things as a pack (currently 7). Some puppy training required one on one time. I do require a structured environment and required all to mind. I believe discipline is a must, especially when dealing with giants. That is not meant to say I use negative, cruel or abusive training methods.

    Later, as adults, they all are very social and have helped many rescued fosters de-stress, relax and recover. They are, and always have been, very social to dogs and humans. Now as seniors they still snuggle, do everything together and are best friends. It is great to experience the special bond litter mates have for each other.

    The worst experience was when I lost one. The pack did mourn, especially the lost’s litter mate, but everyone did move on.

    Even the two different sets liked each other, but not as much as their own sibling. Perhaps the generally mellow Mastiff temperament is a factor. There are always exceptions, but I certainly would not hesitate again to bring in litter mates when the time arises.

      1. The fact that they spent lots of time apart between 8 weeks and 6 months could be a huge factor; they had plenty of time to develop their own personalities and experience the world without their sibling. This is key. There is a strong genetic component as well, and your giants may not be predisposed to it. Plus you obviously know what you’re doing! Thanks for your perspective.

      2. I’ve no doubt it does happen. However, there may be more to it then just being litter mates. I know some that swear multiple dogs of X breed have problems with each other even when introduced as unrelated adults. Sometimes males, sometimes females. Sometimes rescues need to be the only dog. They are all individuals.

        Not sure about the second comment spending lots of time apart, mine have always been together. Maybe it was intended to be in response to a different comment.

  31. Four and a half years ago we brought home two female Beagle puppies. They started fighting the day after we got them and it just escalated from there. No one warned us about the problems we would encounter such as them failing to pay attention to us and only focussing on each other and it was only after searching the internet that we became aware of this syndrome. We persevered for 6 months, training, feeding and walking them separately but the fighting escalated until they were hurting each other (and us when we tried to break up the altercations). It got to the point where I couldn’t go to work because I had to keep them separate. We eventually had to rehome one of them with a friend and they have both been calm, happy and well-adjusted dogs ever since.

  32. I am not seeing this. We have giant schnauzer littermates that will be two years old the end of January. They are male and female. We have had the female since she was eight weeks old and the male off and on after that but at about six months he came to us permanently. She is very alpha so we started socializing her heavily as soon as she had her third puppy shot. At eight months of age she started basic agility and attended a puppy class. After he arrived, we did not socialize him as much but he has now also started in agility classes and has been to a carting demo. She has done lure coursing and herding. She is far more mature than he is, but I think that is somewhat the nature of male and female giants. They were not neutered until they were almost 19 months of age to allow their bones to fully mature. We do have other giant schnauzers that they play with. Two other females who do mother them and keep them in line when needed so it is not just the two of them. We have other male dogs that the female of the litter plays with. He is very OCD about chasing balls and toys and retrieving. I also do giant schnauzer rescue and we have taken in and adopted out several pairs of littermates. One was a pair of male giants. We don’t like for people to have same sex giants unless they are very familiar with the breed and know how to handle them.

  33. To respond to the comments about breeders and rescue groups encouraging people to adopt or buy litter mates, responsible breeders do not sell litter mates to a buyer for the very reason explained in this article. I have bred dogs in the past and refused to sell litter mates to buyers especially if they were unexperienced dog owners. I will interview and investigate the buyers, check references, and get to know the people and their experience with dogs and the breed in question and based on the outcome of the investigation would then decide whether or not I would sell them litter mates. However, a general rule of thumb is to refuse to sell litter mates to inexperienced owners. Responsible breeders do know about how difficult it is to raise two dogs of the same age be they litter mates of from different litters. Obviously, the woman who bought two “chiapoos” did not buy from a responsible breeder as a “chiapoo” is not a breed, they are mongrels and the “breeder” was only breeding these dogs to make money and cared nothing about the dogs.

    1. If the buyer had other dogs or enough people to work the dogs and give them time I would. I am a responsible breeder.

      1. Older established dogs in the household seems to be a mitigating factor. Enough hands on deck to give each and every puppy born a rich socialization, whether littermates or not, and the problem would all but disappear.

  34. Loved your article. Did not know of these problems with litter mates and the rescue encouraged us to adopt both the six month old cocker spaniel/silky terrier sisters together. They are now two and a half years old and very happy dogs, good with children and other dogs, although one is more timid. I did have problems with training and walking properly on a lead. Puppy school was a disaster and they had to be taken separately. I’ve not seen any aggression towards each other and they play well. They sleep together but are happy to be apart when inside. The timid girl is much more people oriented and happier to spend time with me rather than her sister and she was easier to train. I am so happy we don’t have any major troubles as they are both adorable. Thank you for all the information – I also really enjoyed reading the responses and comments.

  35. Interesting and informative article….unfortunately for the dogs, one, two, three or however many dogs people decide to raise(train)??? is all about how they train(raise) them….just like human children; if you don’t discipline and train them, they will grow up to be problems…i have raised(trained) many sibling puppies and it takes A LOT of energy, just like raising children, of which I raised three. It is ALL about how you deal with them, whether you let them be the alpha or you are the alpha…….all human babies and canine babies are trainable.

  36. As a serious small breeder of quality purebred terriers, I have always refused to sell littermates to prospective buyers. A single puppy of our breed is sufficiently challenging to even the most knowledgeable owner!
    I also require that the pups leave my home at 8 weeks, the most favorable bonding age. Recently, I made an exception for a buyer who wanted a pick bitch at age 12 weeks, so I kept the 2 best bitches much longer than I had ever done before. They formed a mini-pack and caused me concern. Now that one has left, the damage does not appear to be lasting. My little bitch and her littermate are thriving in their separate lives. But I will never do that again!
    Thank you for spelling it out. I will send this article to any future buyers who are asking for littermates or who want a pup older than 8-10 weeks.

  37. My ex husband and I fostered 2 beagle mixes in the early 1990’s from a local rescue. The puppies were around 3 weeks old and the mom had been hit by a car. By the time they were old enough to be adopted by the agency, I couldn’t let them go. We did have littermate issues but they were very mild and mostly funny; we’d give them both a toy and they would chew, cuddle, within inches from each other and growl, grumble, glare(guarding). if we moved them and the toy to a distance apart they didn’t like it and would return to ‘inches’ apart and continue cussing each other out. We didn’t do the socialization we should have because we didn’t know about it. They were happy, reasonably well adjusted, well trained although in a 2-dogs-1-brain sort of way, and accepted other dogs, cats and people. Years later when they were around 9 or 10, fighting started, infrequent still, but it was always the same dog getting hurt, once ending requiring stitches and in a serious infection that didn’t heal easily. We had to be much more watchful and never quite figured out what caused it. Could it still have been a late arrival of the more violent part of the fighting littermate syndrome that had only exhibited as grumbling? We were fortunate with them but I would never do a littermate adoption again. I’m a part time dog trainer now and really try to advise against it when I can. Great post and comments. Thank you.

  38. I had a pair of sibling labs in one of my classes, and one week the female came to class with sutures over her one eye, and when I asked what happened the owners told me that the male had bitten her when he was stealing her food. They also mentioned that the female will crouch over her food and eat quickly. I recommended that they feed the dogs separately. The male owner basically told me that they were his dogs and he would do what he wanted with them, and my suggestion was dumb and the dogs would “figure it out.” One week only the male was in class, and he almost couldn’t function because the female wasn’t there. I also warned them that letting the dogs “figure it out” would probably esclate and they would end up with major vet bills. Unfortunately they all unexpectantly stopped coming to class, or communicating with me at all, so I really hope nothing too terrible has happened to the dogs. I have recently started talking about Littermate Syndrome in some of the classes that I teach, mostly the puppy class when sibling puppies (who are owned by different families, luckily) are in class, we highly encourage the pups to interact with the other puppies, not just each other.

  39. I have raised sibling Scottish deerhounds, one sib set at a time, for over thirty years. I have never had the problems you mention, but it was likely because I was told very early on by a reputable trainer that it was important to separate the siblings for eating/sleeping/ training experiences early on, as you recommend. Most reputable deerhound breeders do not hesitate to sell siblings to experienced owners, especially those who like to show, course and hunt–the reason? Because with the giant running hounds, it is nearly IMPOSSIBLE for an owner to give the puppy the degree and the KIND of exercise they need to fully develop into a functional sighthound. If you are writing an article to be widely published, you should talk to a few deerhound/wolfhound/greyhound breeders.

    1. Most Deerhound breeders also keep their puppies until they are at least 12 weeks of age. Raising puppies in a pack situation, keeping them with sibs until this age makes a huge difference in their responses to the outside world. I have no problem selling pairs of sibs to experienced people. As Mary Ann says these dogs need a huge amount of exercise as puppies and it needs to be on their terms not on a humans.

    2. I’ve lived with sighthounds (Borzoi, Scottish deerhounds & Whippets) for 35 years. With the large breeds, it’s much easier to grow them out well if they have a playmate of the same size & style. In one case it was a borzoi & a deerhound bitch, born a day apart in different states which came home together at 10 weeks. Currently, 3 year old dog & bitch Borzoi litter mates are the household youngsters. Although they slept together in the same ex-pen as little puppies, they ate sedately from the beginning, tho’ not in crates or separate rooms. They continue to go to classes separately, and they frequently show on different dates to different judges. When Phoebe is in season, Eddy goes to camp. They do not quarrel, but Eddy is very much “me-me!” and will push his smaller sister aside if he can. As the owner, it is my job to make him mind his manners and wait his turn for attention. They are both clearly bonded to me as well as each other & the senior dogs in the pack, but they don’t freak out if I hand a lead to someone else if I need to step away for whatever reason. I am not unique among Borzoi breeders & owners in this.

      1. I would be interested if this syndrome exists in all breeds. I have seen it in GSDs and Cattle dogs but not in my somewhat limited experience with Site hounds.

  40. I am a breeder and show my dogs. I usually keep one to two puppies out of a litter for showing and I have not had any of these issues. Of course, I socialize quite a bit and the puppies are taken to show matches separately and together. I have never had this problem with litter mates. I can see how a “pet” person who doesn’t show or train their dogs for some type of performance event may have a problem but I haven’t had this. I have only sold litter mates once and they turned out beautifully and the owners did not have any problems. However, I should note none of my puppies leave the house until they are almost four months old. The breed is Norwich Terriers. I do believe socializing is the biggest responsibility we have as breeders of any breed.

  41. Thank you for such a good article. I was a foster failure and kept two litter mates. I got them when they were four weeks old. One male one female. I talked to a well respected trainer locally and the first thing she told me was to take them separately anywhere several times a week. It was a monumental task but I took one to the park then one to the store and the saga goes. They will be four in July 2014 and they have different sports. I trial with the female in agility and the male is a therapy dog and trials in rally. I have just this month started to take them both to the trials of each other. QUESTION: is this a mistake?
    They play hard together and run like the wind ( they are flat coat retrievers) they have acres to run on but you can see they always keep their eyes on each other and sometimes the play is rough, but they always settle into their “preferred corners” in the house.

    1. Heck no, no mistake there. Man, those pups are lucky to have you: One does agility, the other therapy and rally. Once again, a focus on giving them separate identities and ample opportunities to understand the world, people and dogs and you can end up with co-homed dogs as functional as any two dogs, siblings or not. The article points this out. That said, it’s impossible for most people to do. Your dogs are lucky, and it sounds like your are too! Kudos!

  42. I have 2 Saints that are litter mates. However we did not rescue one until they were 10 months of age. We rescued him from a home where he was inadequately cared for, never socialized and needed vet care badly. Both were great and didn’t show any of the symptoms until this past April when they were about 18 months of age. Max ( the rescue) barks and lunges out of fear at other dogs and people. He is great with my family but no one else. Moose whom we’ve had since age of 11 weeks is laid back and loves everyone and everything.

  43. We just adopted littermates three days ago,10 week old girl and boy great pyrenees and shep x. We had no idea of this problem. If we split them for six months do you think this will prevent the problem?

  44. We have a brother and sister littermates…the male we got when he was 7 weeks old but did not get the female until they were 7 months old.. Although we are convinced they knew they were littermates even after being seperated we have had nothing but great experiences with them. They are very attached to each other but love to interact with everyone, including other dogs (we have 2 cats in the house also). Our primary concern is how they will adapt if something should happen health wise to the other…it will be a great loss for all of us!

    1. They were not together during the developmental stages that would have caused problems. It’s not that they are siblings, but if they are littermates who are never apart. All dogs who live together grieve, that’s normal. Sad, but normal.

  45. We got our two Alsation x Collies from a shelter and not only are they littermates (2 of 11), they are bitches and they were orphans who were not put with a surrogate. We now know they received no mothering discipline and that same sex siblings can show greater rivalry. We had disastrous time at puppy classes so stopped going and have trained Bess and Abbi separately with good results, managing to train to voice and hand signals. Although house training has been very difficult with both pups clearing each other’s messes and although 99% of the time our house no longer stinks is not fully implemented yet (they are now 6mths old). We feed and play them together but always put the dominant one first, maintaining what we perceive as the natural hierarchy. We walk them separately as it is virtually impossible to go out together however the one left behind becomes very agitated – whining, pacing and scratching the door, especially the dominant one. This is when they get 1-1 play and training time in an attempt to distract and reinforce/strengthen the bond with us. The only time we all go out is to the beach. So far so good (I hope) the only other syndrome we haven’t been able to curtail is the fighting. As yet this is not overly aggressive and we intervene with a distraction noise (verbal “ac-ac”). We trust this would be alleviated once they have been spayed?
    My husband and I are not young and not in rude health, everyone has advised us to re-home the dominant one for the pups’ mental stability and also for our sake but we are loathe to do so. Beautiful Bouncing Bess and Abigail Dolores Malone have wonderful temperaments and great with our grandchildren just crazy together.
    Does anyone have any other advice or suggestions? Is it just a question of a bit more time, patience and several boxes of tissues?

    1. My main question, beyond why you are keeping both pups when they are showing all the symptoms of the syndrome, is why you are waiting to spay them? Make an appointment today. This may not change their behavior now, but it will save you lots of problems down the road. Littermates with symptoms in heat would be a nightmare. It sounds like you’re making the best of a bad situation, but not one I would intentionally enter. That they had no maternal direction make it even tougher. You’re a trooper for moving forward and I wish you the best.

      1. Thanks for your good wishes, spaying booked. Have searched out other owners of littermates locally, the support and extra advice to try different ideas has been wonderful (just knowing we’re not alone in wanting to keep our girls is keeping us sane). Also got a “dog-whisperer” on board with experience of the syndrome. Turns out that whilst life is more difficult and at times stressful our situation is not unredeemable.
        From experience so far my advice for anyone wanting 2 dogs would be to get one puppy at a time with at least 6 months in between, However if 2 at once is the commitment then get yourself armed with as much info as possible from both sides of the argument and ask your local vets/pet shops/breeders for a recommended trainer with litter syndrome experience willing to come to your house. Knowing what you’re letting yourself in for is half the battle. Of course, dogs all have differing personalities and keeping littermates does not always work out but at least you will have the knowledge that you tried everything you could.
        It has only been a week since tearing my hair out and feeling like the worst dog owner ever to knowing that there is light at the end of the tunnel. Having outside help is key and asking for assistance is not a sign of weakness or inability to cope – it takes a strong person to stand up and admit to needing someone else.
        Good luck.

  46. This is very interesting and I had no idea. Thank you so much for the article!

    I was wondering, can this syndrome exist for puppies that are not raised together, but are siblings and raised in the same family. In my specific case, (and this was years ago) my brother’s dog had puppies. He kept one and I took another (the rest were given to good homes and we never saw them again.) At first we would socialize our pups together and they were fine. However, after they were a couple of years old, they were very antagonistic towards each other. We never brought them together again main because my brother’s dog (who was bigger) would growl and snap at my dog. I’m wondering if this is littermate syndrome. This is just for my information, as my family is close and we often visit with each other & bring our dogs with us and I would never want this to happen again. Both of the dogs described above are now gone (it really was years ago) and all the dogs we have now all were adopted from different shelters and came from different litters.

    Thanks for your time!

  47. I am getting an 8 week old choc girl and 9 week black girl lab from 2 different litters. I had planned to do separate kennels and training and LOTS of socializing. Glad I read your article. Any advice greatly appreciated

  48. Thank you for this information. I have been running a puppy rescue for 10 years and people get so mad at me when I refuse to adopt litter mates or 2 puppies together. I am thrilled to have something in writing to back what I am saying to them.

  49. So true. I’ve been saying this for ever, how annoyed would you become if you had to live with your siblings during adolescence the rest of your lives. Pissed. Lol. Overwhelmed. It’s so true, when they have each other from such a young age, and then no educated guidance or leadership on the dog owner or dog lover, usually, in this case. They become so enthralled in each other. They never spend time apart. They become this intense tight knit unit that is a very primal pack almost, where they know human is not leader. My only question would be, could this happen, adopting two pups in the same development stage, different litters, or breeds. But one tending to be a companion breed, she now latches on, in many of the described ways, aside from the extreme dominance, but it does happen? Or would that just be a simple dysfunctional pair. Because one has no confidence without the other, the other doesn’t notice the other leave. Two clients of mine. The weener dog had a bulldog sister, both puppies, grew up together, then suddenly bulldog passed away. Then they got another for her the weenie, and now she’s just completely lost without her siblings, the other has no issues, but also has more confidence. Very neat how dynamics develop without a structured eyeball watching lol

  50. Hi Jeff,
    My two older huskies (who were not fixed at the time) had a litter. Originally my boyfriend and I had intended on keeping just one puppy, but after falling in love with the runt of the litter, my boyfriend and I decided to keep two. They are fantastic play mates (only 9 weeks old) and my two older huskies are fantastic with them. I have been noticing that when outside together, they dont seem to listen to the humans, and when in the house they are more focused on each other and their toys, instead of playing with us. My boyfriend and I are in this for the long haul and are prepared (and recently have been) keeping them separated, feeding, playing, walking, socializing, and training solo. Is there anything more we can be doing, or any advice that you could send my way? Id really hate to get rid of one of the puppies as we adore them, but of course want whats best for them.



    1. Having older dogs in the picture seems to reduce the chances or severity of the problems. Just make sure they get lots of quality time apart. I am not sure where you live but if you have access to puppy socials, take each separately to 7-10 before 18 weeks so they each get a chance to learn the nuances of dog language from pups other than their siblings.

  51. Thanks for the advice! Just another question, Ive noticed that they’re already becoming very attached to one another, and not responding to or bonding to my boyfriend and I. Friends of mine have offered to “foster” one of the puppies for a month or so just so they can have some separation, do you think this would be beneficial?

    1. That could work, but I would do this for month than a month. I would look a reuniting them after sexual maturity (10 months or so) and make sure both are highly socialized and well-trained in the meantime.

  52. I have two 8 month old Jackapats a boy and girl. and after reading some articles became worried of what they may grow to be like. Luckily so far, all’s good! when they start to become sick of one another we simply separate out their activities one does training and the other goes walking and when greeting other dogs we have found their bouncy energy can be very overwhelming for other dogs so they greet separately and calmly. They have had no problem bonding with humans and rather curl up with us than each other. Their success may be due to the fact they are polar opposites the girl bold and brave, though is submissive to the taller loving lanky wimp, her brother. both have been neutered and spayed, so fingers crossed their will be no problems in our household.

  53. Hi Jeff,
    more than two years ago, Oct.2011 to be exact, we adopted two 8 weeks old English Cocker Spaniel siblings from the same litter and I happen to read your article before we brought them home and I was terrified to the point when I called the breeder asking if it’s not too late to get just one puppy and she refused to refund us for the second puppy so we ended up taking them both. But I was prepared to deal with Puppy Syndrome and my girls started basic obedience training at the age of 12 weeks, were spayed before their first heat, were sleeping in the separate crates until they were one year old. Potty training wasn’t difficult at all, each of them have their own favorite human, they bonded to each other, but it’s nothing like you mentioned. They love people, excited when they meet a new dog, never fight!, great with sharing their food and toys, play with our grandchildren, who are 2 and 6 years old, do not show any signs of aggression at all! They don’t like to be separated but don’t get anxious when one is taken out. I can go on and on for hours… My point is – the owner must be aware of this Syndrome and be prepared to work twice as hard and, of course I think that human must be in charge and set strict rules when raising puppies.

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  55. Hi, I wanted to just voice my experience. I have two blackmouth curs that I rescued at 5 months old, they were the last of a litter and both males, looking almost identicle. As they are hunting dogs I expected some agression but it got very bad at times. Having raised them with my girlfriend thru the latter portion of college and now we are into our early careers, they have calmed down immensely with eachother and socialize very well with humans (dogs, not so much). We found some techniques that helped a lot – crating is a must and separate crates especially, we feed them separately as this was a trigger for most of their fighting at a young age, now there is little to no aggression with food of any sort (other than bones, they still get agressive with bones), we schooled one that seemed to be more agressive, the only one that would show agression toward me, and this helped a lot as well. side note: they are both fixed – a lot of agression went away after making this move. It’s now almost 4 years we have had them and it’s a great feeling to see the bond they have developed with one another but also with my girlfriend and me as well as each of our families. Our dogs have endless personality and I wouldn’t trade them for the world but it was A LOT of work, almost too much. I wouldn’t advise anyone to do it, and had I known before hand I may have not rescued both of them, but I can’t imagine a life without both of them in it. Anyhow this is a fantastic article and I feel for those people struggling with sibling dogs, but if you really love them and want to keep both as we did, (unless there is literally no hope in sight) stick with it and socialize, train, feed, crate, SEPARATELY and maybe they’ll start to come around as my boys did.

    Good luck and thanks for the write up.

    1. Kevin,
      My comment is not about your experience, other than to say thank you for sharing. When I saw that your experience is with Black Mouth Curs, I had to write share that my husband and I rescued a female Black Mouth Cur almost 2 years ago and she is such a joy! This was a breed with which I was completely unfamiliar and I’m so glad we took the plunge. They are such warm and loving animals. I would adopt another Black Mouth Cur in an instant.

      Thanks for sharing your story.

  56. Thanks for this article, I had never heard of this syndrome. I’m about ready to adopt and was considering getting two, but now I’ll wait and get a second down the road. I’m kind of relieved, too, because I was dreading the chaos I was about to impose upon myself having two at once! Win-win!

    My dad got two at once, and some of the symptoms were there. They didn’t fight often, but when they did it was bad! When the bold one passed away prematurely, the shy one blossomed into a loyal and protective companion. We hadn’t realized how repressed she was until her sister wasn’t there to steal the show, so to speak. Even though she stopped barking at dog walkers passing by her fence, she remained unpredictably aggressive around other dogs. We didn’t see anything wrong with how they behaved, we just figured they were a pair, always a pair, although, I can remember feeling that they weren’t as close with family members as other dogs we’ve owned.

    The symptoms were mild, but I, personally, wouldn’t want to risk even mild symptoms! I want to give my girl all the advantages I can to help her develop into a well behaved lady. I’ll get one now and one later and maybe the older one can show the younger one the ropes.

  57. This is nothing to do with this subject I did find it very interested being a dog owner for over 45 years . Just a question my neighbour who has a female Husky who breeds her twice a year different breeds of dogs ( German Shepherd now Husky ) selling them as purebred pups I did not think this is proper I actually do t agree with breeding your dog for just the money side

  58. How Long would one have to seperate them for meaning training wise . We adopted two female pure bread boxers being unaware of all this like most people 🙁 we got them yesterday we do however have two crates and are doing everything apart training , eating and play time . My question is how many weeks do we hve to do this before tey can be able to cuddle and spend time together ? Thank you

    1. They can spend time together now, but they need to spend lots of time apart. How old? Get them to puppy socials, separately, if under 18 weeks. Separate crate, training classes, socials, walks. Lots of work ahead of you.!

  59. Jeff,
    I have 2 male American bulldogs that are 61/2 months old(tank and pudge). I have had them since 8 weeks.I have a 10 year old male boxer and a 5 year old male bichon. They sleep in separate crates. and I walk them separately(only because they are 2 strong for me to take both 80 and 75 lbs.) Pudge is good on the leash tank is okay not great. He doesn’t like other dog but pudge is okay.
    when I noticed tank didn’t like other dogs at 4 months old I signed them up for doggie daycare. they did 2 weeks straight and were trained in basic commands. Tank took time but in a couple days the trainers said he was fine there. Plays with 50+ dogs on any given day. They recommend I try to take them 2x a week until adolescence. I had them neutered last week. They exhibit a fear of loud noises.and tank recently shows fear when my son’s friends(16 and 17years old) I tell the friends to ignore him and sit down until he comes to them. it has helped. he adjusts.
    I have always had 4 dogs at a time but never siblings.
    Do you have any other suggestions so they don’t develop into full blown syndrome?

  60. I have a rescue organization. I find that people will give up both ill behaved dogs rather than choose one to focus on. It seems we get pairs of sibling pups that have failed as pets frequently. I NEVER recommend adopting sibs together. When we acquire a litter of pups and someone wants two I won’t adopt two pups to them. I have seen too many situations where both dogs end up homeless. We see posts all the time where people are trying to keep sibling dogs together and I just think how misinformed they are. If you were in rescue and you continued to get these pets six months to twelve months old that are so untrained, you would never even think about adopting a sibling pair!

  61. Hi Jeff,

    We were just discussing this very topic last week. As a Animal Care Center employee and lead on the adoption team this questions comes up regularly. We discourage adopting two puppies from the same litter (but do not deny) and actually recommend waiting a few months before bringing the second puppy into the home. Usually after experiencing Puppy #1 they decide to wait much longer for Puppy #2. Thank you for providing me with an article I can share with staff so that they can reference why we suggest this.

  62. Because of a series of life circumstances, I have female littermates from a litter I fostered 3 1/2 years ago. I was/am very aware and knowledgeable about littermate syndrome. (I also have one older dog and one younger dog.) My family and I have worked (and continue to work) very diligently to offset littermate syndrome. Along with our other dogs, they sleep, crate, eat, go to classes, do therapy and crisis response work, compete, and have one-on-one time separately. They love their individual time and their family time. They are very well adjusted and stable dogs. They have both unique and similar loves and interests. But as I said, their lives and activities have been very planned. It is a great deal of work, but it is an act of both love and responsible pet ownership. Acquiring littermates is NOT something I recommend. But I will help and support those who want to do it and want to do it responsibly and lovingly.

  63. My first reaction was bull, until I read the article. We have rescued and adopted litter mates three times and would do it again. Never had a problem except two Shepard crosses who did show some aggression to each other but eventually sorted it out without any damage. More importantly, we have always had at least one other dog around when we brought in litter mates. Our experience has been that the training curve has not been steep as the new dog or dogs watch the older dogs and learn from them. I feel like we have not trained a dog in years because they learn so quickly from the older dogs and people always comment on how well trained they are. We also have the advantage of four adult humans in the house so there is seldom a time when there is not someone with the dogs and we all love dogs and interact with them all the time. I personally have never experienced the syndrome but it would appear that this is a result of our particular circumstance. For us it has not been an issue and have never found litter mates to be more work than single dogs. In fact, we have never found any dog to be work, including abused rescues. Love, patience, grooming, feeding, vetting, daily playing, walking and cuddle time are all pleasant and easy to do and will turn the most nervous, distrustful dog into a happy dog.

  64. I found the article to be accurate in its predictions of the issues you can expect with litter mates. With that said, there are exceptions. My wife and I have had two sets of litter mates and both have worked out fine. But, we are both very experienced trainers, handlers and obedience and agility exhibitors. The first pair produced an OTCH who competed in three AKC Obedience Invitationals and an OTCH MACH who finished tied for ninth in an AKC NOI. Both dogs also competed in National Agility Championships.

    We were aware of the issues with litter mates when we got them. But the litter was so exceptional that we took the risk and went ahead. As puppies, we crated them side by side, fed and played with only our own dogs and only let them play with each other about ten minutes per day. And we did have two older dogs in the house to handle some play time and “show them the ropes”. The results were outstanding.

    Our second set, (this an arranged breeding), came along too soon. The first set was only seven years old and were just hitting their prime, showing wise. As a result, even though we used the same procedures as before, they didn’t get as much personal attention as the first pair. Our bad. Both of these dogs are also excellent obedience and agility dogs, (one MACH), but not up to the level of their uncles.

    They are now eleven and we are quietly pondering another “arranged date”. The older boys will be twelve by then, their show careers over, and we’ll have the time necessary to build the relationships we should. But it’s a lot of work and dedication by both owners. If you don’t have the experience, time and willingness to do what we’ve done, don’t do it.

  65. I do agree for the vast amount of people in the world, one dog is one too many to raise properly. However, I have raised 2 sets of littermate puppies, and adopted a third set at almost 9 years old from a “novice” owner. None of the dogs had issues, in fact, most went on to become great show and obedience dogs, all of whom are/were exceptional hunters. I do believe it is how dedicated one is to each pup as an individual instead of relying on the puppies to train each other. Either that, or I should start writing books and going on the road, because I have had none of these issues….lol

  66. Very interesting article. Years ago I purchased two male Beatle littermates and this problem. Lots of fights. Went to UC Davis but nothing really worked. Had to keep them separate most of the time or keep muzzled on them. Now some 30 years later I have GSDs and some times have to keep them apart if same sex. I am thinking of having my young male’s sister come and live with us. I own the father and a daughter. I know the 6 year old daughter will probably not get along with the younger half sister so will keep them apart which I can do. I don’t think the female littermate to my 20 month male will have this littermate syndrome as they have not been raised together but have had visits together and get along very well. I do take them places separately and each have been left alone during their first 20 months. What do you think?

  67. Thank you for your article on littermate syndrome. When I first began to explore the dog fancy world, my mentor explained the potential pitfalls of raising littermates. As a result, I have never considered it nor had I thought about the potential problems that can arise from separating bonded dogs as adults. I recently took in my sister’s Bouvier after her husband transferred to Mexico City for work last fall. Her behavioral problems including inappropriate barking and urination in the house made it impossible for my sister to take her with the family. Tessa is extremely timid and skittish. My sister adopted Tessa at almost 2 years old from a breeder that I have purchased a number of dogs from in past, including adult dogs. Tessa is now 6 years old. I have worked 3 dogs from this breeder as mobility assistance dogs and had a couple others as pets that I’ve worked in obedience and/or rally. My sister’s bitch was one of 2 that the breeder kept to breed and show in confirmation. Unfortunately, the breeders husband became seriously ill and was hospitalized after Tessa’s litter was born. I suspect that they did not get the attention her dogs normally get due to the circumstances. Tessa acts like a fearful dog. Her tail end ears are almost always down. She will often try and make herself as small as possible. Sometimes, Tessa will beg for attention when I call her while other times she will cower in the back of her cage. At first, I thought she was fearful of my oxygen and mobility equipment. But, she will come running towards me, with her ears up and tail wagging if I have her food bowl in hand. The only other time she shows a normal, confident attitude around me or the other human members of the household is when she knocks our 2 male Bouviers of the way to get first dips at the water bowls after coming in from outside. Sometimes, she will bark at the human members of the household for unknown reasons. I can understand barking when someone comes in but she will bark if we go to the bathroom at night or sometimes when we are relaxing on the couch. She also barks randomly. We have not been able to figure out why she is barking. My 8 year old male has just started joining in. This is not pleasant at 2am. At first, I thought she might need to go outside but she refuses to leave her crate. I have tried taking her to beginning obedience and agility but she shutdown and refused to participate. It was obvious that the classes were too much stress. After extensive work, she will walk around the neighborhood but I have been unsuccessful at teaching some of the basics like”down.” She does “sit” and “stay” for food. She has to be muzzled to be groomed as she will bite you if you touch her front paws. Despite these issues, she was good with my sister’s 3 young children and fine with other dogs. I would say she prefers dogs to people although I believe she gets on better with my males than she did with my now deceased, alpha bitch. Lady would frequently discipline Tessa for inappropriate behavior. After reading your article, I am wondering if some of Tessa’s problems stem from being separated from her littermate? I am at a loss on how to help Tessa as I haven’t even been able to identify all of her fears, much less treat them. I would rehome her but I doubt that I would be able to find someone to take on her rehabilitation. I hope you will consider expanding your article to cover how to rehabilitate a dog with littermate syndrome.

  68. Unfortunately we learned this the hard way. We adopted two female litter mate Beagle pups at 8weeks old. One seem to settle in while the other always seemed to have high anxiety and crying which led to the calmer adjusted sister to become very stressed out trying to comfort her sister. I tried to rehome 1 pup with no luck. We ended up re homing both pups to a family with a ranch who had many other Beagles. The family kept us up to date and the girls seemed to have adjusted.

  69. I have two sisters, German Shorthaired pointers, that are 7 months old. We fostered them, their mother and 6 other siblings from when they were 4 days old for a local GSP rescue. We decided to keep these two, however the rescue did warn us about raising two at the same time. They told us that they would be harder to train, and may focus on each other rather than us. They are harder to train, but we have two older GSP, a 7 year old female, 3 year old male, and a 5 year old doxie, and 2 year old Chi, so I think that has helped immensely with their socialization. We like to give them separate playtime with the other dogs, and that has really helped. I can see why it would not be recommended to keep siblings, because you really do need to work at it all the time.

  70. I have two brothers, Yorkshire Terrier who are both 11 weeks old. The problem is, even though they are together, one of them keeps whining whenever I am not with him while the other is mellow. They both listen to me well, play with me, and do not fight a lot. I am thankful for that. But one of them is potty trained while the other one has trouble using the pee pad. Any suggestions?

  71. Great article! I had two litter back in December. One here at home and another earlier litter in a different home. The litter here produced a singleton pup. When the other litter was 8 weeks old I brought home two of those pups and introduced the singleton to her 1/2 sisters. Placed one of the older pups 2 weeks later. I have been carefully raising the two remaining pups. Both are wonderful pups and very well adjusted – but I’ve made sure they don’t sleep together and we have done things separately from early on. Long story short, I could see that neither pup was thriving. They loved each other, the older dogs, and me, but there was something lacking. I decided to place one of the pups. Yesterday one of the pups went to her new home. In just one day the difference in the pup I kept is dramatic. She is attentive, her focus is great and in a very short training session she learned to sit and walk on a loose lead. I’m a very experience dog person and knew raising two pups together was going to take some work, but I was up for the task. What I’m so glad I realized is that raising them together wasn’t best for either pup.

  72. With all due respect, claiming littermate syndrome does not exist just because your particular dogs don’t have issues is like saying learning disabilities can’t exist because your kid is a gifted student. I can’t believe you would have made the comments you did had you bothered to read the entire article, which explicitly states that there are exceptions and that problems can be avoided with proper socialization and training! Read the article, then read the comments; many owners have had these symptoms occur in their sibling dogs, sometimes to devastating effect.


  73. Jeff,
    We started fostering our two hound/lab mix female puppies at 2 weeks old. After bottle feeding them, there was no chance of them going back to the shelter. Of course I starting finding out about the syndrome after adoption and acting fast, crating them separate rooms, feeding separate and when I could, walking separate. I could definitely do more, but as your article states, it’s exhausting. They are only about 9 months old but we are constantly at the dog park and doggie day care. They play wrestle constantly but it’s rare that it ever gets out of hand. They are fearful of unfamiliar people sometimes. They spend their days of nice weather outside together while I’m at work. But once I’m home, one will be upstairs with me and the other will be downstairs on the couch. They do get a little jealous of each other at the park but all in all they’ve been good. I realize they are still very young, so I guess I’m hopefully it doesn’t get bad from here. But in the future I will get one, train, then get another. I think this information definitely needs to get out. My shelter said nothing about it either.

  74. I raise and show Beagles and Dalmatians and I work in a veterinary hospital. Years ago I was told by many breeders they never sell litter mates to the same family. They explained that often they would be hard to housebreak, bond with each other and often fight. I took the advice to heart and would always try to discourage people from getting 2. I have seen all to often the negative side of having litter mates with clients dogs.

    My first litter of puppies I was encouraged to keep them til they were 10 weeks old. There were 3 beagles in the litter and I was happy to enjoy them longer. Sadly, the extra two weeks was hell! They started fighting and trying to establish a pecking order and I spent all my time seperating them, not enjoying them. I was so happy when the 2 puppies left and I was able to enjoy the one I kept.

    I did keep litter mates in my last litter. There were two gorgeous puppies and I had planned on keeping the girl to show but couldn’t find a show home for the boy. I made it a point to separate them for two weeks when they were 8 weeks old by sending one to a friend. They were crated and trained seperately and I will still send one on “vacation” to my friends. They get along wonderfully in my “pack”, and the extra work and training has helped make sure they are confident, happy and obedient dogs. It has been a wonderful experience BUT a lot of extra work! I definetly wouldn’t plan on keeping litter mates routinely!

    1. I wonder if keeping two of opposite genders makes a difference? This discussion has caused me to think back to 1993 when we brought home a deerhound stud fee puppy bitch, stopping en route to collect a little borzoi bitch that was just a day younger. Might the fact that they did not meet until they were 12 weeks old make a difference?

      1. Sure, the more difference the better (see Dr. Bain’s comments in the article), so different genders are better than two same-gendered pups. And getting them after 12 weeks would make a difference too, because that’s when the second socialization period ends.

  75. My female shepherd had a litter of 8, I knew I was keeping 1, but my husband & son wanted one of the males also. They are 9 mths old now, have had no issues. I have momma and dad at home too. They have gone through obedience class, now they are working on their CGC, momma & dad both have theirs. It is a lot of work, but can be done, I also work full time. If you know what you are getting into and are willing to do your best to socialize them it can be done. My son is working on getting the male his therapy dog certificate, he wants to take him to visit people in the hospital, they are both awesome puppies, love people and other dogs.


  77. I wish I would have had this article to refer to a year and a half ago. I work in rescue focusing on senior dogs and hospice care. We took in boxer/lab brothers, 10 years old. I think everyone assumed that since they were together, they should be okay with other dogs. That couldn’t have been further from the truth. Wyatt was the dominant of the two. He was always “on guard” and never fully relaxed. There was something about one particular female boxer of ours that he did not like, and he would tear down multiple barriers to get to her and fight. Virgil was overly submissive, looking to his brother for social cues. He clearly had no confidence at all. For safety reasons, we ended up rehoming Wyatt as an only dog. Even then, his behavior remained a challenge until he passed away. Virgil is still with us. He has had a more difficult time adjusting, but his confidence is growing and his personality is starting to shine through. He is still not comfortable with our larger dogs, so he lives on a separate level in our home. We have managed to socialize him with our 6-year-old JRT/red heeler mix, Nismo. Nismo is a very confident, “show-him-the-ropes” type of dog, and he has worked wonders with Virgil. I don’t know that he’ll ever be comfortable enough to live fully integrated with our other dogs, but we work around it.

  78. I recently rescued 2 6-week old litter mates (boy Chihuahua mixes). I am highly aware of litter mate syndrome and have had them sleeping in separate crates and walking them alone for 3 weeks. However, even though I am trying to spend time with them alone, I am single and live in a 1 bedroom apartment. The puppy who is by itself will cry continuously while I am with the other one unless I leave the house. I am not sure one person can do a great job at this. On the other hand, both puppies seem very social with all people and most dogs, even while on their “alone” walks. I have 2 questions:
    1) How traumatic is it for an 8 week old to cry while I am spending time with the other one?
    2) If/when I decide to re-home one, how do I choose between them? At 8 weeks old, they are different but I can’t tell how they will be as adults…I love them both and it does feel like a Sophie’s Choice situation – though not nearly as tragic for the puppies – just for me!

  79. I need some advice. We are picking up 2 whippet puppies soon , both same litter, and male pups! We did not do our research before agreeing on 2. We just thought they will be good company for each other whilst at work. Wasn’t until someone at work mentioned this littermate syndrome.. I am now concerned. I want them to get along, treated fairly. Whippets have always been in the family, but none have brought 2 together like this. Thy have always been different ages. We still want to do this…we are 2 determined people. We just need some professional/ experienced advice please? We would of thought being the whippet bread we wouldn’t have too much of a problem with the type of nature they are. Can you help please?

  80. Hi Jeff, I have a question regarding the littermate syndrome issue. I work at a humane society in my town and after years and years finally have the ability to take home a dog, and wouldnt you know it, the dog I always said I would have “someday” just walked in the door ( 2yo red merle aussie male)! I have spent a lot of time with him and am in the middle working to take him (I am living in a no-dog apartment but will be moving to a ranch soon) and wouldnt you know it, ANOTHER “someday” dog walks in (1yo blue merle aussie male). I havent gotten the chance to spend as much time with the blue, but already he has taken to me and I would love to take them together, but I found out from the shelter owner that they are pseudo littermates (same mother, different years, unknown fathers), and all came from the same home that was having issues because they were trying to keep 9, semi-related working dogs with minimum interaction and brought in five of them saying they “just didnt herd.” The reason the red came in so much earlier is because the owner thought he was the one instigating the problems, but now several weeks later has brought in four more because that wasnt the case.
    I have no livestock and I dont care if they herd, since any herding I do would be as a hobby. Id like to take them both, but the shelter owner (who I trust entirely when it comes to dog know-how, she has been at this a long time), is worried about adopting siblings, even ones so distantly related.
    I guess my question is, how strong is littermate syndrome and would you suggest only taking one dog? The older dog has been at the shelter for several weeks and gets along swimmingly with other dogs and people. The younger dog is a fairly new arrival and is still being kept alone since he is not neutered, but for the most part seems to come out to see people and doesnt mind other dogs walking by. They were raised together, and I suspect allowed to pack up with the other dogs in their previous home, but like I said seem alright now.
    So the summary:
    -Raised together
    -History of packing up
    -Came from same home
    -Out of same mother
    -About a year apart
    -Are currently kept apart with no issues that Ive come across (the younger whines a bit but that is common for dogs that are recently dropped off)
    Do you think there would be a significant chance of them packing up with each other? All articles on the subject Ive found have been about puppies coming from the same litter, but like I said the owner seems convinced it can happen no matter the distance.
    Any thoughts are appreciated, thank you!

    1. Littermate syndrome has to do with socialization not occurring properly due to the same-aged puppies focus on each other. These dogs with a year difference in age will not experience this particular problem. They may do great. I would adopt one and see about taking the second on a trial basis. I would still work with them separately (it’s almost impossible to effectively train 2 dogs at once because you’re looking for complete focus on you, not divided between you and the other dog.)

      1. Thanks for the quick feedback!
        Realistically I may not have the time or space for two little bundles of fur and energy. My thought was that they might help keep each other busy if I was unavailable, since leaving intelligent breeds alone for any amount of time is asking for trouble! But I see the potential problems with that too. It may not be littermate syndrome per se but something similar, the packing up that they were doing when all nine of them were together, that the shelter owner is worried about. I will definitely talk to her again though.
        Thanks again!

  81. Wish I had read this 18 months ago! 2 Siberian huskies, the boy goes into “mourning” when seperated from the girl -even if just in a different room for 30 seconds! Socialization with other animals is fine (have 7 dogs). Just separation and bullying issues between the two.

  82. I bred my first litter last summer. Longhaired mini Dachshunds. Which I show. For several reasons, I ended up with the pup I intended to keep and one other (both females), even though I am a firm believer in not having two pups at the same time. I knew from the start that one girl had a more outgoing personality and the other more laid back. Things went okay for a while and then as they approached their first heat cycle around 6 months, the more outgoing girl started to bully the other one. It got worse as the months passed and there were some bad fights. I could see how it was affecting both of them and how it was going to change them. For me the decision was clear. I found a wonderful family for the softer girl. They send me videos and pictures of her all the time. I can see the wonderful, positive difference it has made for both pups. Both of them are happier, play more and are way more into interacting with people and other dogs. Proving right before my eyes something I had know as fact and now I have seen it.

  83. Please could you help with a bit of advice, i have 2 8 week old Pitbull pups, i never really took note of any of the problem until reading this article. Every thing you mentioned our pups do in one way or another. Whilst eating the female is not able to eat an entire meal on her own with out running to her brothers bowl, i figured this was due to been used to suckling, they do play a lot and are very loving towards us as owners, some times during play they do get a little aggressive towards each other but that’s when i break it up and slow them down, i figured this is normal behavior for dogs as dogs do play. I don’t think i have much to worry about currently as they are showing what to me is normal puppy behavior, i am now concerned after reading this article and would like to prevent this syndrome from occurring. There are many solutions i can think of for this scenario but would like some advice on the best option please, (best option is not re-home one). Would a solution be to separate them, for a few nights and days a week to learn to be indipendant? Male stays with me female with my girlfriend, they stay at her place for a day and night and day, then come spend a night and day back with him? or should we push for 2 nights? We can separate them at home my concern is if they cry they will hear and smell each other, been separate they can learn Independence and bringing them together for a while will keep them as companions?

    Please advise on any recommendation you could provide me.


  84. We adopted brother and sister dobes and it’s worked out for us. Maybe it was different for us because I stay at home so I was with them all the time, but they were always fine with other dogs and people. I trained both with a trainer. I will say it was more work to train them and they didn’t always listen when chasing balls or if they saw a squirrel and started to chase, but neither did my first Doberman, and he was here by himself. We did eventually get a 3rd dog which is a Boerboel and she fit in great. So I guess it can work, but you need to plan to put in a lot of work for everyone to fit in and be happy!

  85. I’ve adopted two liter mates in the past and absolutely loved them and had no problems, but that was only because I got lucky. They were purebred Great Pyrenees (which people familiar with that breed will tell you “aren’t really dogs”) and they were brother and sister. (Great Pyrs as a breed sometimes don’t adjust well to same sex parings) They have done just great as LGD’s (livestock guard dogs) and they are well adjusted enough socially to be taken on leash in public without any concerns about their interaction with people. Like I said, I got lucky, but I don’t know if I would be brave enough to gamble on it with any other breed, or with same gender pairings.

  86. I have 2 pitbulls; one male (intact) and one female (spayed). They are litter-mates and I have had them from birth. The difference I think, in my case, that they get along fine (they are 9 yrs.old now) is that I raised them with their mother there with them until she died when they were about 3yrs. old. The mother helped me SO much in their socialization skills that it was made easy for me. They NEVER even chewed anything but their own toys (all of the other puppies I have owned did). The only thing I am starting to worry about is with their age I don’t know what’s going to happen when one passes on. They have been together all of their lives. There is no fighting or aggression issues (again, probably because of 5 yr old Mom). I can very well see how this could have turned out different and would not get 2 pups again at the same time as it was hard to train them. They HAD to be trained separately, because what one wouldn’t think up for mischief, the other would! I feel very lucky to have “dodged the bullet” with these 2. Any idea about the death separation? (Life separation is okay).Thank you for your info,

  87. A very well-written article. My daughter bought 2 male (crossbreed) littermates about 3 years ago. Luckily, their behaviour is fine and they appear two well-adjusted young dogs. Both are neutered. One dog was the runt of the litter whilst the other was the largest so there is almost 100% difference in size – perhaps the better for it, from what you say. They also interact individually with the family, each having their own personality, and with other dogs too. They’ve always shared their bed and definitely have a strong bond – the downside being that they fret if separated but my daughter’s lifestyle is such that they seldom are and get plenty of interaction with other people and other dogs. I can see it could have turned out very differently. Good advice from you to share. 🙂

  88. I’m curious to know if this applies to non-siblings, as well? As in two relatively-same-age pups adopted from different litters at the same time?

  89. I had a father of a litter and we kept 2 of the litter mates. My brother also took 2 litter mates as well from the same litter. My Mom took one and MY Mother-in-law had the Mom and one of the litter mates. The puppies were all female. This was when we knew we couldn’t be breeders. They stayed with the family. We had no trouble with littler mates. The 2 sisters I had couldn’t have been more loving to each other. One of them just cleaned the other sisters face and ears all the time. It was quite sweet. The whole story of this collie story was a beautiful story. I thought about writing a book about it.

  90. Hey I have a dog, Japanese Spitz X, for the last two and half yrs. Brilliant little dog listens to and does interact with me. However he is hard to train to do tricks all he does is ‘sit’ could not train him anything else as he just didn’t seem to quite figure out what i was asking of him and he does not listen very well atall to my partner. With other dogs he can be very aggressive and growly for a long long time(still growls at my mothers dog after two yrs). He can be extremely timid and submissive when it comes to new people and if I’m doing something different in the house ie moving furniture even an inch or even lifting ornaments of shelves. He was reared on a very small pen with his father until he was 9 months old I wonder is this something similar or is he just timid and dependant on me?

    1. It is the same in that it is a lack a socialization. A small pen with his father? No interaction with other people or dogs? That is a shame. All dogs can be trained though. Find a trainer in your area that does clicker training

  91. I am just now hearing about this, which is sad. I absolutely LOVE both of my dogs(brother and sister). But knowing this problem when I adopted them, I probably would of only got one. Mine are almost a year old now.
    They don’t seemed very attached. I mean one can go somewhere and the other is just fine. The agressiveness is what I have seen. It’s kind of like the sister annoys her brother, and he won’t put up with it and will fight(we’ve only had one bad fight). I’ve tried trainers, and they’ve never said anything about this. So my question can I make this agression stop? My male can’t go places without of people because I am afraid he would bite..I thought it was out of fear? My female is fine, not very sociable but can go out in public and be good. We do not take them to dog parks or anywhere with a lot of people/dogs around together. Too much to handle. I’ve been trying really hard on fixing them. Taking them individually to a pond to let them see different things. If there’s any advice you could give me, it would be GREATLY appreciated!

    1. To add on…I do train separately. So no problems there. I’ll go outside and have them both out there..the sister will fetch the ball while her brother just roams around. I got them when they were a couple days old and bottled fed them(became very attached at kept them). I saw you comment and say that could be the problem with someone else’s. I just don’t like the agression towards each other sometimes. It doesn’t seem they’re attached…but like they piss each other off. Since it doesn’t seem they have this full syndrome, maybe they’ll grow out of this.

  92. This article is excellent information. My boyfriend and I adopted 2 chihuahua mix’s about 7 months ago. We got the first one, and felt that it may want company and also that the people we bought him from were very neglectful. So we went back that night and got the other. Between the two, the larger one at that time ate well. Used the bathroom well. And was playful. Over the next few months the larger one, slowly became the smaller one. Apparently we believe the mother was mini pin, and the fathers are different. One was chihuahua, and the other is obviously mixed with dachshund. The chihuahua mix began to become a picky eater. We noticed he would go almost a day at times without eating. He became nervous. And sort of like a really frightened baby. It was not until just this week when I decided that I wanted to make the bedroom off limits to the dogs in the day time. I began to notice heightened agitation from the dachshund towards the chihuahua. He has attacked him several times, and I have always been on edge wondering when he will loose his sh*t on him again. Through the process of beginning to set new limits and noticing heightened behavior, we stumbled upon a writing about “littermate syndrome.” It was really an awakening moment. We are lucky because there is two of us, in a one bedroom apartment so it is easy to separate them now. Beginning last night one of us slept with one on the couch, the other in the bedroom with the door closed. We have decided to raise them separately this way from now on. The chihuahua seems to be extremely care free, and almost confused that no one has their eye on him constantly. And the dachshund its having such a hard time adjusting. We are using Cesar Millan’s techniques of not rewarding the state of mind that creates that behavior. And although they are 7 months developed, we are getting a crate and beginning crate training. If the dogs are in the same room we don’t allow the dachshund to approach the littler one, as a result (since this is the very beginning of the adjustment) the larger one has been going nuts! He almost instantly tries to attack the smaller one. This information on littermate syndrome has been life saving. I never noticed that the littler one, never played on his own before. Never took walks outside on his own before. The larger one constantly interjected into every aspect of him. We thought they are just being dogs and the bigger one is just an aggressive personality. SO THANKFUL to realize that we can choose to raise them “separately” and have a real effective way to solve this problem. I think that this issue needs to be on Oprah and people need to know that if you are adopting two of the same litter, You HAVE to treat them as individual dogs and not allow them to grow up “together.” This information has saved my little dogs life and I could not be more thankful. I didn’t realize it was something like this. People out there may not either. We have to get the message out. Thank you for your efforts! Sincerely, Charles

  93. Of course this is the first I read of this. About six years ago, we got two beautiful goldens from the same litter, both males. The bond they had was like none other. We experienced some of the signs mentioned, but they also were very social with people and other dogs. We lost one of them yesterday to a short but intense battle with cancer, and we are trying to help the surviving brother cope. We are torn apart as he runs around looking for his brother. Are there any resources out there to help us? much love, kc

  94. We’ve kept and raised siblings for many years – male and male, female and female, and in the past and currently – female and male. Never had a problem. I guess it’s all in the know how.

  95. I found this article very interesting but it doesn’t really follow my family’s own experience at all. Ten years ago we adopted 3 boston terrier puppies, 2 were littermates and 1 was half sibling to the other two puppies. They were all raised in my parents house with my older female boston terrier (4years older) for the most part but roxie, one of the full siblings was my sister’s and did spend evenings and weekends at her house with her 2 year old boston, rascal, at the time. After the first year roxie was at my sisters full time with rascal The 2 boys (half siblings to each other) stayed in the same household until 4 years ago when i moved out and took my 2 dogs, the half sibling (teddy, 6 at the time) and the older female (noelle). I am curious why we never had this kind of problem with the 3 puppies, could it have been the stabilizing influence of a strong assertive pack leader in noelle?

    1. Again, it is not just that they are siblings that causes problems, it’s a lack of socialization and time apart from their littermate to develop an individual ability to relate to the world, humans and other dogs. The fact that one of the full siblings spent evenings and weekends apart from her sibling provided this.

  96. Hi Jeff! Quick question for you…

    Last May, my boyfriend and I adopted littermates separately. His puppy was his, and mine was mine and we did not live together so the puppies spent a lot of time apart. Now, however, that boyfriend is now my fiance and we live closer to one another and spend most nights together, the dogs have spent nearly every day together since March of this year.

    They are Chihuaha-Daschund mixes. The biggest behavioral problems we have had are jumping/ over-excitement and chewing. They fight each other a lot and get nervous around other people, but warm up over time. We’ve made a consistent effort to socialize them (especially with my parents’ 3 mini-daschunds) and I think it’s helped. Do you think our dogs are still at risk?

  97. The article is good and certainly worth consideration when bringing home dogs or littermates. I, however, have littermates and do not experience these issues. In fact, my dogs (Boxer breed) are very social with both people and other dogs. They also take separation in stride. My dogs are well behaved, know not to leave the front lawn (based on training, not electricity) and weren’t overly difficult to train.

    The only thing I think this article is missing is that dogs are pack animals. For folks who both work and no one is at home, not having a mate can cause separation anxiety in dogs and lead them to do awful things to your home and/or themselves. Therefore, I think stressing how much a companion is important for dogs, whether it be another dog or someone who is often home, is important.

    Great article, look forward to more!

  98. We rescued two catahoula mix female puppies that are now 3 years old. We are beyond the point of being able to give one up so I was wondering if you had advice to my predicament with them. The biggest issue with them which is partly breed, partly our poor socializing and partly the sibling issue, is their anti social skills with other people and other dogs. I can’t seem to find a way to introduce them to other dogs very well. Any pointers? The other main issue is the separation anxiety they each have with each other. I tend to do everything with them as a pair due to time restraints. By separating them in activities do you believe I’ll see results or is it to late?

  99. Jeff,

    Looking to adopt two puppies from the same litter (male and female). They are 10 weeks old and after reading this page and all the responses, I am concerned that the behaviorial issues would prevent the puppies from benefitting. If we were to delay adopting one of the pair, at what age would the socialization issues become less of a problem. Many of the comments indicate that littermates do quite well if properly socialized first. Can we delay adoption of one and have less likelihood of running into problems ? If so, how many weeks would you recommend ?

  100. Great article! Thank you so much. I manage Animal Behavior Programs at the SPCA of Texas. This is a wonderful piece to share with management, staff and volunteers to explain why I discourage adopting two puppies to the same home. Sure, there are exceptions to the rule, but why risk it?

  101. We have 2 sets of littermates and I think we’re one of the lucky stories. We haven’t experienced any of the symptoms of littermate syndrome, our dogs don’t mind being separated – in fact, they self separate. And everyone gets along beautifully. I don’t know what we did differently or if we just got lucky with the dogs who joined our family, but I do tell people that working with a dog trainer is very important.

  102. I believe that though this may be the norm to warn against, there are pairs that have a bonding that is highly compatible. If the responsible breeder senses this, they should be there to explain the bonding and training needed in a homing situation.

    I find that in general, the stronger bond is often mother to a female puppy.

    But especially with brothers, sometimes the best scenario is that they find homes where they get to have play dates and frequent visits with each other.

    My two 10 year old brothers have been able to have that all their lives, and I think it has been a big enrichment for them, even though they don’t see each other daily.

    Sara Watson, CTC
    Bluefence Bassets
    Member of the Basset Hound Club of America

  103. I run a rescue and have raised many sibling puppies, some of which have been adopted together. I’ve never experienced any of these issues (thankfully), but I socialize my dogs as much as possible with people and other animals. Even in my home there are 10-15 dogs at any time so puppies are socialized well even at home. This is the key for anyone thinking of adopting sibling pups… socialize, socialize, socialize. And don’t feel bad about taking one out and leaving the other at home, everyone needs a break from their brother or sister, even dogs. Try to attend training classes where pups are allowed to interact but again, take one and leave the other at home or register them for classes at different times. Having siblings dogs can be successful, it just requires a little more work than putting them out in the back yard and thinking that’s enough.

  104. Thanks for this article. Very thought provoking. I’m a volunteer trainer with a shelter in NYC who took in two littermate girls from a rescue in Peurto Rico. They were originally picked up as stray puppies. They’re now about 9 months old and have been with us in NYC for 3 months. They came into the rescue already very scared and withdrawn; they’ve made some progress, but not as much as any of us had hoped. They are very bonded to each other and very scared of most human interaction as well as pretty much everything outside their kennel. It’s hard to know how much of that is due to poor early socialization and how much is their over-reliance on each other. BUT… I’m wondering if there’s any research about the timing of separation. How old is too old to separate bonded littermates?

    1. I do not have a good answer about when/how to separate. My focus is on trying to keep this from happening in the first place. Sounds like you got them at 6 months. If they had had no human interaction before that, PLUS they were with each other the whole time, well that’s a particularly tough situation. I recommend that you get a veterinary behaviorist involved.

  105. Our rescue Finn was purchased with his littermate when the backyard breeder recommended taking a second pup so they wouldn’t be penned alone. Finn’s original owner was seeking a golden to replace the one he had recently lost who was the best dog he had ever had. He said they were always together & Tuck adored him. He couldn’t understand why neither one of these pups ever bonded with him like Tuck. I told him when we were discussing his disappointment that he made his mistake from the start buying 2 littermates & explained why. From the article: “as they squeeze the owner out of the relationship. They’re always living with an enormous distraction—each other.”

    The brothers were penned up together until they grew big enough to get out of the pen. Then they were placed in the yard together with an underground fence. When they kept running through it, he took off the shock collars & they ran loose in the neighborhood always together. While they were still penned, I went over and asked if we could bring them over to play with Shai who loved playing with any dog he came in contact with. I was looking for dogs for him to play with, and they lived across the street from Bart’s mother, But they would never engage in play with Shai although only a year old and the same age as Shai. Even though they wouldn’t play, we felt sorry for them being penned up so Bart kept bringing them over for a little most days. They would just grab all the toys and carry the toys around but not play with them. We stopped getting them when they started running the neighborhood. Then Finn’s brother was hit by a car, and Finn watched him die. From the article: “Cohabitating siblings may become so emotionally dependent on each other that even short separations provoke extreme distress.” That is when Finn ran away from home to our house and refused to stay at his house anymore. Even now, he doesn’t know how to play with Shai & Rani.

  106. I have 3 English Springer Spaniels. The first female was 12 weeks old when we got her. I knew I wanted 2 females. I had the time to socialize and train, so we went to a different breeder for the second female. They are 3 months apart. When we picked up the second, she had a littermate brother that was twice the size of all the puppies. We left with only the female. Within a week my husband continued to speak of this great looking MALE dog. Did I mention I never wanted a male dog? So 1 month after getting his sister we were back. Yes 3 dogs!!!! They all have separate crates. I knew about the risks of getting littermates, but took the plunge anyway. We have an open invitation at our house, if you come to visit, you must bring your dog. They socialize well. I wonder if it helped that we waited 1 month before getting the littermate? They have had many training sessions $$$$. They live with 2 cats and 10 free range chickens. Yes, bird dogs trained to like chickens. Great article!!!!
    Signed… Lucky in RI!! Oh and I’ve learned to love male dogs.

    1. IN dog behavior, there are rarely “cures”. The purpose of this article was to discourage people from adopting siblings, not a guide on how to address it, especially after such a long period.

    2. One ‘cure’ might be to find an experienced dog-owner friend willing to take one of the animals as a guest for two-weeks or so at minimum. See if you notice any change in either or both animals (and your own quality of life). If things go well, you’d realize that everyone (dogs and humans) might be better off if one of the littermates is rehomed. And one or both of the dogs will show enough recovery to be on the way to being suitable for a new permanent home. Worst case scenario, you aren’t emotionally capable of seeing them separated for even a mere 2 weeks, in which case you probably shouldn’t own even one dog.

  107. Is there any decreased risk if siblings when they are older and at different times – not leaving the breeder together at 8 weeks of age. i.e. as an example – one pup placed in home at 10 months old and the second placed in that same home when 14 months old. Interested if the lapse of time and living apart makes a difference or if this has not been considered. Thank you for your time!

    1. Not sure about that long period with the breeder – 10 months and 14 months. If the dogs spend most of their puppyhood apart, getting socialized and developing as individuals, you can definitely bring them back together later

  108. Hi Jeff, I really enjoyed the insight you provided in this article. I am currently residing two pups myself, but they are from different litters. My husband and I couldn’t agree on a breed, so we got two different dogs. We have an eight-month-old shih tzu/bichon mix and a four-month-old border collie/aussie mix. They do not mind being separated, although they do enjoy each others company. Whenever I have guests over, they are perfectly friendly. Outside the house, they do tend to be a little timid with new people, but they warm up as soon as they realize the person is okay. They are very friendly with other dogs. However, there is a lot of aggressive playing. It is not constant, and I often break it up. The shih tzu has some jealousy issues though and goes after the border collie every time I give him a lot of attention. The border collie used to allow the shih tzu to be dominant, but he is getting bigger and is starting to fight back. How long so you believe the struggle for dominance will last? Is there anything I can do to speed things up? Do you think they could have elements of littermate syndrome? Thanks for your help.

    1. No I do not think this has anything to do with littermate syndrome because they are different ages. This is pure puppy dynamics. You might want to work with a trainer if it gets out of hand. Puppy play can look pretty brutal, but as soon as it crosses the line, give the pups a time out.

  109. We have two Dachshund sisters, litter mates, and have not seen a serious problem. Rather, they have been a joy. One appears dominant. Curiously, the dominant one nursed on both her mother and a lactating Labrador. The other can be quite aloof. They have very distinct personalities and both seem to relish their alone time. They both have preferred play activities. The dominant one likes fetching the ball, while the other is more interested in hunting varmints. And when little Miss aloof does catch the scent of a varmint then they hunt as a team. One might chase a squirrel, where the other will block the path to a tree. One will dig into the front door of a woodchuck den while the other looks for the back door to catch an escape. The dominant one is more aggressive with strangers and other dogs, while the other is much more social. Overall, I don’t think I could have trained a better team. The hunting strategies they use are very sophisticated.

  110. I would like to say that I have two chiweenie puppies, now ten months old. From a youg age, we exposed them to as many other dogs as possible. Golden Retrievers, pit lab, lab, other chihuahas, and our shih tzu as well as my mother in laws older shih tzu. We have made sure to introduce them to new people often. They are very friendly, almost completely potty trained, and very bonded. One of the girls is more bonded with my fiance and the other with me. They sleep together and like to be together but definitely notice other people. I guess I got lucky! They get scared when they first meet new dogs but adjust in less than 5 minutes. We made sure not to “rescue them” when they got scared around new dogs and made them stay on the floor. They have learned how to sit and soon we will teach them some other tricks. The only downside I have seen is they like to get into mischief together, (chewing on things) it took them longer to train, but we make sure they get individualized attention. This article was very enlightening. Now i know what to watch for

  111. I will say however, when I first got them, (Lola, and Aurora) My Lola was very aloof and didn’t seem to bond with me much. I had to consistently give her individualized attention to get her to bond with me. now she is definitely mommy’s girl!

  112. We have a 10 month old boxer/pit mix. He is a great HIGH HIGH ENERGY DOG. We have gone through 3 types of behavior/socialization classes (one day of 8 weeks each) and we aboslutely love him. Due to his high energy we were thinking of getting another dog so he could have a companion to get all of his excess energy out. It seems like perfect timing-just on facebook today I see that one of his brothers from the same litter needs a new home! And then a friend told me about littermate syndrome…. Hence how I found this article… But I find that the syndrome is more with dogs that are immediately raised with their littermate… but that raises concerns as well.
    Some info regarding our pup and the one that needs a home

    Our dog: Titan
    Has been raised with cats and has been around children somewhat (he is very jumpy so we have been concerned. Gone through several training courses, is neutured and up to date on shots. Loves car rides, does well on leash (which is new, A LOT of training has been done) but is not able to be off leash due to too much distraction during recalls. He is crate trained, but is able to be left alone for a few hours at a time, (and recently at night hogging the bed)

    New dog: Puddle (we have not met Puddle yet, but this is what we’ve been told)
    Puddle has not been raised with cats, but has been raised with children AND their sister from the same litter. He is NOT neutered and NOT UTD on shots. We are told that he is good on and off leash but can be jumpy at times and VERY high energy just like our dog. We are told he is crate trained and is crated when no one is home and at night (due to playing with his sister)

    My BIGGEST concern after reading this article:
    How is Puddle going to adapt being away from his sister and now with his littermate brother?
    Does the littermate syndrome not apply anymore due to them being seperated for the last several months?

    Obviously no one will know ABSOLUTE answers, but some opinions would be great.
    Thank you!

  113. I am currently in litter mate hell! With 2 female Cocker Spaniels! Although they had fights before but only 3. And it was over 6 years, so I guess we were lucky. The last 3 weeks we have had 5 fights and nothing seems to be getting any better. We have been working with a dog behavioral specialist, but it appears there is a litter mate issue of a power struggle that isn’t getting fixed. We have a very tense house and the dogs are constantly in a state of unsettledness. We have to watch them every moment when they are out of their kennels! We actually have 3 female cocker spaniels all from the same breeder. The oldest is not a litter mate and has different parents, although from the same breeder but is 6 months older than the other 2. We had her for 4 weeks then went back to get the pups who were then only 10 weeks old. We have made the hardest decision that one of the litter mates needs a new home before they have a bad enough fight that they are seriously injured or we are or one kills the other. The though of giving one away is killing us they are part of our family! But the thought of them hurting each other is worse! Not to mention that the way we are living now is no life for any of us!! I wish someone would have told long long ago before we ever bought them maybe we would’ve made a different decision! I blame my breeder very irresponsible to sell us not only to later meets but then another one from the same place it’s been difficult at best even with three because the two littermates do not like the third dog, and although they do not hurt her in anyway or fight with her you can totally tell she is inconsequential to this scenario and always has been! Because of the difficulties we may end up giving to the dogs away one of the littermates and then the third older dog, at this point we don’t know what to do, it doesn’t appear that anyone can really help us, and if there was a way to get the situation in control and do something about it we would, but at this point we just don’t know what else to do! I’ve called 2 other dog behavior specialist and no one can give me any good advice, and although we work with somebody who comes to our home she doesn’t find it necessary to come any earlier than October 8 to help us and the other behavior specialist that I could get to come to the home can’t come until after that!!!! And quite frankly we feel like we are in crisis,,

  114. We adopted sibling chihuahua’s. One is male and the other female. Honestly the only issue we have had is potty training. They have come a long long way but still having accidents if we aren’t paying attention. They still sleep in the same cage at night but we do separate them sometimes…one will go in the car with my husband to pick up the kids and one stays with me. We have two older chihuahuas one of them has taken on the roll of surrogate mom and she will discipline them when needed. Four dogs is a handful but our hearts are also full and the puppies who are approximately 8 months don’t seem to fall in to the “syndrome” category.

    1. Hi we’re getting a male and female cocker spaniels at 8 wks. How much time can they be together a day? Can they just be in separate rooms the rest of the time? What about at night, do they have to sleep separately?
      Sorry for all the questions but we are committed to the 2 so need to make plans,

  115. Hi this is the first time we’ve had 2 pups. Our last spaniel Barley was 2 when he came to us. We committed to 2 before we realised it could be problem. Just got to do our best and find out the best way to proceed. pups coming 1st wk November.
    Like to hear from anyone who can give some asdvice/help with this..

  116. yes yes yes listen to the man, i did it 10 years ago with two sister- puppies and it works, when you do all the right things you will be rewarded and very tired! seperate as much as you can and more

  117. I have two 7 mth old male GSD littermates! I got them at 8 weeks! I don’t have any problems with them other than the fact they are twice the work! They have the very odd rumble, usually wen trying to win my attionsion!! I think the fact that I have two older dogs, a male and female, is a big help! They are put in their place very often! The also sleep in a group, but the pups may choose to sleep with one of the older dogs rather than it’s sibling!!

  118. Hi Jeff! 🙂 Thanks so much for this information! I had no idea! Would love your input on our current situation….. My husband and I just got 2 black labs back in September. They are now 4 months old today! We have them in 2 separate crates in the same room, and have two separate play pens where they eat and also have some toys. We also let them out separately when they have to go potty. We did try to walk with both of them, but they instead just wanted to play with each other, so my husband goes in one direction, and I go in another… so I guess we also walk them separately. Their “grandmother” (my mother in-law) also takes one puppy at a time every now and then for a sleep over at her house. However, they are getting trained together, and go to the vet together, and sometimes they play together outside and inside the house when we give them free range of the house.

    They both seem happy and excited when meeting new people and dogs, so I don’t think they are showing signs of the Littermate Syndrome just yet, and I hope they never do! We do want to get rid of the play pens eventually, but have been hesitant to do so because of a couple different reasons (see below). Do you have any suggestions on what we can do in this instance? How soon do you think we can get rid of the play pens?
    – all they want to do inside the house is to play with each other. Sometimes just running around the house trying to get each other’s toys. And then eventually just rough housing, and don’t want them to get hurt.
    – We’re not sure if they will try to eat from each other’s food and water bowl (the one eats all of his food as soon as he gets it, and the other takes his time and picks at it every now and then)

    How do you think we are doing so far? Do you have any other suggestions? We would love to keep both of them if we can avoid this syndrome. The main reason we got two is so that they could keep each other company when we’re not home, but just like you mentioned, we did not realize that this syndrome existed nor how much work it was going to be! Please, any advice helps!

    Thanks soo much!

  119. Wow, I never heard of this before, but now that I have, I see the problem with my two pups; they aren’t siblings, one is male one is female, both fixed, but they certainly have all the signs you mention of this syndrome; we love them both dearly, They aren’t even a year old yet, but all these problems are showing themselves, they whine and cry if they are not within eye shot of each other; they do spend a lot of time playing, sometimes I think too aggressively, and someone else would consider it maybe fighting. One seems to follow whatever the other does; and other than basic commands, training has been very frustrating, especially walking and trying to socialize them; the female is more dog aggressive at the park, while the male is not, if he’s alone; but if he’s with her, he does what she does; we also have an older smaller Chihuahua (6) and the male constantly aggravates him; I think he wants to play with him, but the little guy just doesn’t want to be bothered and is constantly getting aggressive with him, and he’s getting frustrated as well…my question would be, how do I know which one to give up; either one is going to be devastating for us, but I don’t want them to be unhappy or unmanageable either, and its causing much stress in our home; my husband and I are always arguing because I think he’s not interested in training, but now tht I read this, I realize it’s not the training issue; its this syndrome…they cannot be walked without being at least a block away, and then when they see each other, the constant whining and barking – as if they’ve been separated for weeks…yet its only minutes…Obviously, my Chihuahua is not going anywhere, but I’m torn – if we have to decide which of the other two may need to go…I can’t believe no one told me about this before; my heart is broken. We cannot afford to get a specialized trainer for this, and because they are getting older, we are worried this may get worse, especially the playing/aggression…we couldn’t figure out why neither of them were working with the training so well, but this all makes sense now…

    1. This thread has been very helpful. Lots of good information.

      2 months ago I bought two italian greyhound littermates (m/f). I had no idea about these problems at the time. I live alone and work from home, so from a time standpoint I didn’t think I would have a problem. However, I was wrong!

      Initially, I spent the first two weeks sleeping a max of 4 hours straight. I think that was partly due to the breeder (not very good; possible puppy factory). Then they finally started to calm down. From 8 weeks until about 14 weeks, they slept together in the same playpen. I separated the playpen the last few weeks and that has worked fine. They no longer sleep together but are side by side in separate pens.

      I recently started walking them separetly more to reinforce their individualism. They are trained well so far. They listen to commands and know I am in charge. BUT….

      It’s recently becoming more apparent that when they are out playing 95% of their energy is spent toward eachother.

      The play is safe and fun, but it’s become disappointing for me. They are so excited to play that they can’t even lay down separated. Even if one doesn’t want to play, he or she gets instigated by the other.

      It has also been difficult to house train them because there is no “down time”. They will play for hours and I must supervise or they risk breaking bones (Common with IGs).

      I envisioned spending time with them while being in the same room and them being calm. But it just hasn’t happened.

      Any suggestions? I love them both but I’m emotionally drained. I thought having two pups would be more challenging. But I can’t even watch tv with them laying with a toy relaxing. There is no consistency outside the crate and zero bonding with me. I’ve been gone for a few days in business and they defiantly miss me. But it’s really hard.

      Do you think this is a phase? Will they grow out of puppy play and calm down?

      They show some signs of issues but not all. I’d hate to rehome one. When I do separate them they scream and cry for hours. The idea of them never seeing eachother and keeping them completely separated isn’t practical.

      I would appreciate any thoughts!!! Thank!


      1. It’s all in the article which, by the way, was reprinted in Bark Magazine that is on the stands now. I am not sure where you live, but you might want to bring in a qualified trainer or veterinary behaviorist. Don’t rule out re-homing, for their sake and yours.

  120. dont let them play together..take all the time you can get and learn them to play with you…go to a dogtrainercourse….seperatly….they have to socialise with other dogs instead! make the disteance between benches every day [a little bigger….ask someone else to walk one off the dogs..when possibel..i think you dont seperate enough…..i did all off this for months and it worked for my sisterdogs….you dont have much time left to get it right….
    sorry for my english i am from the Netherlands….good luck

  121. As I write this I’m hanging out with two English yellow lab siblings. I’m not the owner, I’m the dog walker, and I found this site after witnessing some confusing behavior in the pair. The owner found me after moving to town recently, as she wanted an outlet for her poorly behaving dogs. She told me she was thinking of rehoming one of the dogs and I told her (wrongly I now think) that she couldn’t separate a bonded pair this late in life (they are 1 1/2 years-old). They are both male, neutered, and gorgeous. When I take them to the dog park I take them in one at a time because they’re quite big and it’s icy out, so they could quite easily pull me over if I don’t do it this way (I should say we never go to the main area, but stay in the private play area so that they don’t harass other dogs). They both cry and scream, even though they’re in sight of one another and are separated all of two minutes. Other than that, they don’t really appear to like each other most of the time. The smaller one (dog 1) is slightly more aggressive and dominant, I think mostly because he’s had to be this way. He likes to chew up stuff, to the point that it’s nearly an OCD behavior. He likes to cuddle, but I don’t see the dogs cuddling together. He’s very possessive of toys and food, and if I tell his brother to sit, he’ll knock him aside and sit in his place to get his treat. He’ll also growl if his brother (dog 2) shows interest in his toy. Dog 2 is much more playful, but he’ll often run dog 1 over while playing. Dog 1 loves to play fetch, but he can never bring it all the way back because Dog 2 will run at him and harass him to instigate a chase game before he can return the ball. But it goes both ways, as sometimes Dog 2 will be off sniffing something and Dog 1 will zero in on him and decide to chase him down and run him over. Often one dog will decide it’s playtime and the other will send signals that they don’t want to play now, and the other will ignore them. The dog will have to respond by biting, etc. until they’re both playing. Sometimes, it’ll be fine and they will both play, albeit one will seem reluctant about it. Other times, one dog will appear clearly harassed. Other times, they’ll start fighting. I see this behavior in their interactions with other dogs. They aren’t necessarily aggressive, but they don’t read the signals other dogs give when they don’t want to play, or don’t like how roughly the boys are playing with them. So they wind up being very harassing. They also don’t seem to have great social skills, despite going to doggy daycare in the past. They approach all dogs straight on instead of circling from the side and I’ve noticed it puts many dogs in a defensive position. Although they’re both clearly very smart, the only command I’ve been able to successfully use with them is sit. Although one of my rules of walking is to do a sit/stay at the door before they go outside, and a sit/stay before crossing the street, it’s very hard to complete these with them. Neither one appears to get it, and it’s hard to get them both to display the behavior at the same time, which I think is confusing for them. Anyway, I’ve noticed several other behaviors too, so now I’m wondering, do I recommend the owner rehomes one of the dogs?

  122. My husband and I rescued female litter mates two years ago as puppies, we are not sure of their first few months of life because they were born stray, but they came to us lacking confidence and very fearful. It seemed with each other as comfort and support they blossomed gaining confidence, learning quickly as we trained and socialized them; we come from big families and they have always struggled with big crowds and young children, we have tried to keep their interaction with children positive and removed them when they became too stressed. While they can be separate from each other while we are around, the few times they have been separated while we were out of the house they have had strong reactions. Luckily we have had not issues with them being aggressive toward each other. We had a daughter about a year ago and now that she has become mobile, loud and interested in them they have shrunk back into the fearful dogs they once were, To keep them from the stress of her movement and to keep her safe they are gated in a separate room for most of the day which is causing them even more stress.
    This is the first I have heard of litter mate syndrome and I question if this is an issue for them or was it their hard start at life or is it who they are? My husband and I are struggling with the thought of giving them up for adoption thinking they would need to stay together, but recently a family expressed interest in one of them. Do you think this could help their behaviors? If so, how do we go about it? Will their age be a factor in whether or not to separate them, most of the comments above seem to be young puppies.

    1. Well we have rehomed the bitch of our 2 pups to a really nice family in our road. It was just too much to try and raise 2 pups and keeping them separate in an ordinary house is impossible. Our advice-just don’t try it and rehome 1 as soon as possible. The difference in the pups is amazing.

    2. Do you have a friend who might dog-sit one of the animals for two-weeks or so to see if separation improves either dogs’ behavior (and your own quality of life) in positive ways. IF things are demonstrably, observably improved, that would make the decision to find a permanent new home for one of them an easier emotional win-win.

  123. I totally agree! When people want two dogs I strongly encourage them to take on one pup now and to wait at least a year before introducing another dog into the household. And adding another dog should depend on how well they have progressed in training the first dog as well as how well they will be able to train the additional dog to be a good “stand alone” dog. Great information for you to get out there, thank you!

  124. How does this all work when you bring home one puppy in December and then a second in June? They are both born in the same month but different litters, breeders, etc. ? We also have a 5 year old. They sleep in the same crate at night – should I separate them? They wrestle together like crazy. I feed them in separate rooms. I also show the one and not the others – so he comes with us for those – we don’t bring the dog we don’t show with us. We definitely found that the second one picked up ALL the bad habits of the first one.

  125. I raised two Newfoundlands who were twins, and the only survivors of their three puppy litters. I never had any of the problems you mentioned in your article, but I must admit that Newfies (and here I am biased, i know) are not like the average dog.

  126. Jeff, thank you for your articles. My adult son and I have 11 month old sibling golden retrievers. They live apart but get together for play dates often. He has relocated and we will house the male for a few months until he is settled. When together, they rough house and and play constantly. My female is the dominant one. They are sweet and not destructive. How can I best deal with this short term situation? It’s pretty wild when they are together! Thank you for your help.

    1. This is not the problem outlined in the article. Siblings raised separately with frequent interactions is fantastic. And I would expect 11 month old golden retrievers to play hard. But they should both be in some sort of obedience training, however informal, and their commands should be employed often, even during play.

  127. Great article! I sure wish I would have found this before adopting our two puppies. I regret I did not come across this in my research. Having said that, my wife and three kids are all very much bonded to the dogs and giving one or both of them up would be heartbreaking. They are a strange mix as the mom was a mix of Irish Setter/Greyhound and the father was a mix of Golden Retriever/Labrador Retriever/German Shepherd. They are a brother and sister of the same litter and are 10 weeks old today. Since they are not fully house-trained, they are staying in a part of the garage that is warmed and has a doggy door at night and while we are gone. They are pretty good at going potty outside and when we are awake and inside, they are getting better to go potty outside. I am concerned, though, about this Littermate Syndrome. They both seem to have a great time together, but the female, though she’s a little smaller, seems to want to dominate the male, who seems more easy-going. We have fed them at the same time and taken them on potty breaks at the same time and we have noticed that they are always swapping food dishes multiple times while eating. Recently, we noticed some scratch marks on their bellies from biting each other. Is there hope to train them and learn to socialize with other and at the same time get along if we start separating them more? Should we have them sleep in their crates in separate rooms at this point? When should they be spayed and neutered? Are they okay to be together in their garage/backyard area for 4-5 hours during the day while we are at work and school? Any advice is much appreciated.

    1. I am not sure where you are located, but you should probably find a CPDT-KA certified trainer in your area to go over these questions. They definitely should spend lots of time apart, and yes, as the article states, in separate crates. I personally would rehome one and focus on the other. Perhaps not as many issues with opposing genders. Speak to your vet about spay/neutered schedule.

      1. Thanks, Jeff! I am in the Sacramento, CA area. Do you have a list of CPDT-KA trainers in this area? I will schedule an appointment with the vet. I heard that too early spay or neuter will stunt their growth. Is that true? Thanks, Jim Sent from my Galaxy S5 Active

  128. I must say that I have raised 4 sets of littermates (3 sets of Irish Wolfhounds, and 1 Saluki) and have never had any issues. Even our Saluiks who were together in many shelters and rescue groups before we rescued them at a year were fine after a few years. We just lost one a year ago at 13, and the remaining Saluki really did not seem to notice his lifelong companion was gone, he is perfectly content.
    In all of the cases I did not make a special effort to seperate them, they would/ will be seperated on occasion due to circumstances, and when one passed the others were fine.
    That being said we always have 4-8 dogs, are all very well socialized, we show, do some coursing, educational fairs, etcetera. and 2 daily walks per dog, so perhaps our dogs way of life helps to prevent this issue.
    It might also be breed specific, Irish Wolfhounds were historically raised in packs in households with their people, they never seem to have sny issues bonding to their humans, no matter how many of them we have.

  129. Wow! I wish i had seen this as well. We recently got a boy komondor puppy for the household for christmas. we’ve had him for over a month and he is an absolute joy. he’s smart and picks up on training immediately, so when the “breeder” contacted us and asked us to take another we agreed thinking two would be easy, as we’re already doing puppy stuff anyway. we gave them their own room with side by side crates and the first couple of days were like a white furry tornado! Jasper, our first puppy stopped listening, and Chloe, our new addition, only cared about playing with her brother.

    We do have a 13 year old lab, as well as 5 children ages 8-19, and are committed to training and socializing, so hopefully we can make sure this doesn’t become an issue. After the first two days, they have calmed down considerably and are competing for our attention during training in what seems to be a good way (they are determined to be the first to sit and be good!)

    After discussing our concerns about littermate syndrome with our trainer, we’ve decided to enroll them in seperate training classes and will make sure we are socializing them seperately a great deal of the time. If there are any issues, I will relocate their crates to seperate rooms in the house. With komondorok (plural of komondor 🙂 ) being a huge and willful breed I want to ensure that we don’t have any behaviour issues! Wish us luck!

  130. Fantastic article – thank you so much for spreading the word about this issue! I just wish I had read it before my husband and I adopted two sisters – terrier mixes that were abandoned at 3 months old. We spent so much time and money on their training and repair of the damage they did to our house. The statement that, “It’s more than twice the work, it’s exponential” was absolutely true in our case. Our particular pups were very stubborn – they just couldn’t learn to behave well, because they only cared about each other. They had a horrible chewing problem (think drywall, leather couches) and we ended up living behind a succession of closed doors and baby gates. They are now almost a year and a half old, and the aggression was starting. I rehomed one yesterday through our local rescue organization (thank God for them, they are angels) and our other pup is already better. Our rehomed pup is going to a retired couple – the man loves to surf fish and the pup loves the beach – I am sure it will be a much better life than being part of the dastardly duo here.

  131. My parents have 5 month old german shepherds (male and female). They were only just recently separated for sleeping, but the crates are end to end so they are not entirely separate. They eat together (she steals his food), they go outside for bathroom breaks and play, and while the male genuinely plays for fun, she gets aggressive quickly (biting his tail, biting and twisting his fur/skin, grabbing his back leg to make him fall). My parents are getting a lot of conflicting advice about training them. The vet told them to let the dogs “fight it out”, the trainer said to let them play fight a little, but if it turns aggressive to separate them.

    I have no idea which is correct, of it’s too late to start doing everything separately. The female freaks out if she’s separated from him, and today she was aggressive and the male has a slight injury to his leg from trying to get away from her. When we tried to look him over to assess it, she whined and cried and tried to step on him to get us to pay attention to her.

    Neither of them listen to even basic commands when they are together. They are not socialised with other dogs except a few visits from my sister’s dog (he’s three) who finds them both really irritating.

    I know my parents won’t rehome either of them, so is there anything you could recommend? I am worried that as the dogs get bigger and more powerful physically that they might do some real damage to one another – her as she’s trying to dominate, and him trying to defend.

  132. It was a really good article but I do have to say it’s not true in all cases my sister in law has to boxers and they are litter mates they love each other true but they love their people and any other dog that will play with them they are 2 1/2 now they have no aggression toward people or other animals they was easy to potty train and they are well behave

    1. The article CLEARLY states that these problems to not occur in all pairs. Repeat: This does not occur in all cases. But some symptoms, often devastating and heartbreaking, develop frequently enough that it is worth considering. My intention with writing this article was to alert potential owners considering adopting two littermates (especially same-gendered, particularly females) to the risks.

      All the naysayers out there, please read through all the comments. Yes, some folks did not see these problems develop with their particular siblings. But when they do, it can be a disaster for all concerned.

  133. Having a litter of female Min Pins, I can attest to the fact that littermate syndrome is a very real occurrence. I have had my girls since they were eight weeks old and they are now seven. It has not been easy. One, in particular, is constantly picking fights with another one. Fortunately, thus far, there have been no injuries. We are working with a vet behaviorist, Dr. Karen Overall, in an effort to help our aggressive Min Pin. My blog post “Something Wicked This Way Comes” details what we have been dealing with in our home. You can check it out at

  134. Hi Jeff,
    This article and thread is a excellent piece of work and it is much appreciated. Unfortunately, This article came to late for me and my family. We bought two shih-tzu Maltese mix. I want to ask you if you can prescribe a system to manage these two dogs. We as a family love challenges and we will commit the time to properly give both these dogs their own identity. I will provide you information information about each party.
    Dog 1: (9 weeks old, male): Interacts great with humans. Have already taught him many boundaries, and limitations. Very responsive with lots of eye contact. Has mild separation anxiety towards it’s sister and us, the humans. We usually teach the rules to this one first so it can be an example to it’s sister. Lot’s of whining. He does not like his crate, he uses it only for sleeping. He loves to interact with humans. Highly curious. Takes submissive role when playing with sister.

    Dog 2: (9 weeks old, female): This one barks a significant amount while playing with the humans and her brother. When the brother plays with her it usually end up with her getting aggressive towards him. She find’s her crate more comfortable than interacting with us. Very nervous, but does not empty it’s bladder when touched petted or lifted. Not to curious at all. Takes dominant role while playing.

    Humans: (5 of us): We all share responsibilities of the puppies and take this matter seriously. We all have friends with well behaved dogs, 4+.

    Please Jeff if you would be so kind to point me in the right direction or any other body of information that deals with this issue. We just want the best for these two beings even if the worst case scenario means giving them away. Once again I thank you for any time you spend viewing my case.


  135. we raised two boxer brothers and no it’s not for everyone. It’s double the trouble,vets bills,pee and poop,training,socialisation and love.
    If you are prepared to train them seperatly and together, socialise them with other dogs seperatly and together and are consistent with your rules and paitent and loving things will be ok.
    It’s the best thing we ever did even though we lost henry on xmas day and diesel is grieving and it is hard I wouldn’t chance anything

  136. Hi Jeff

    I have an odd scenerio. I am in Indonesia and i found two homeless pups that had wondered in to where I was staying. Someone who worked there wanted to kill them. …anyway I took them to a vet who had been recommended to me to help. They were 6 weeks about then now about 3 months. I had thought about taking them back to UK if we can’t find them homes and admittedly was sad if they were to be separated (until I read this blog!)
    The difference is they are still sort of St dogs….Most people don’t keep dogs locked behind gates they are free to roam and So interact with plenty of dogs but then they also don’t get as much affection as we give our pets.
    Do you think 3 months in a kennel facility before leaving for UK would change them or make them bond more and possibly cause this “littermate” syndrome?
    After reading all of these comments it has made me think twice about this. I am not with them now but have been back to see them since I’m still travelling. ….I have really bonded with them.
    Any advice?Thanks

    1. I am never going to suggest that two pups remain together if there is an alternative. I would make sure they are getting LOTS of positive interaction with all sorts of people (the standard is that all pups meet 100 people before 12 weeks of age) and with other dogs (separately, so that one does not become dependent in an unhealthy way his sibling when other dogs are around.) A BAD SCARY interaction with either people or dogs at this point may or may not lead to life-long fearfulness. My suggestion: Keep one, find someone who lives close to you to adopt the other, then give them frequent play dates and train/socialize them intensively. You could then reunite them when they are older and have experienced the world and developed their own distinct personalities and confidence. The problem is not littermates per se, but littermates that are together constantly during key socialization periods, esp. weeks 8 – 18, but I would still have them living/training separately, bringing the second back into your home between 8 and 14 months.

  137. I recently just sent my 6 week old puppy back to the litter to make sure he gets all the socialization that he needs. I plan to pick him back up in 2-3 weeks, and I’m considering also adopting his sister for a friend. At that point, we will only have his sister for about a month before she would be rehomed. Is this going to cause any behavior issues when they are separated? If we get the boy home for two weeks before getting the girl, would this make a difference?

    1. Make sure that during the period you have them both, they spend lots of time separate, including separate crates, separate rooms if possible, but of course time together. You don’t say where you live, but you should start both at puppy socials 7 days after the first shot. A version of this article of mine on socialization before full vaccination is in the Bark Magazine (superb publication, highly recommend to all dog owners) on the newsstands now:

  138. We have two rescue dogs currently. Both dogs were adopted at the same time and male is 2 yrs old and female is 4 yrs old. They get along fine and we have no issues. The female was adopted out of the shelter with her sister as pups and never left their fenced yard and had minimal human contact. At age 2 they were both returned to shelter. Our girl was fostered and we took her in and worked with her. She is the sweetest, mild mannered dog and has bonded greatly with our family (3 teenage girls+husband) although is very shy with strangers. Her sister has remained at the shelter and not fostered and will be almost impossible to adopt because of her shyness. Since we have had such success with our girl, our hearts want to consider taking a chance on her since no one else will. Both dogs get along with other dogs and show no aggresiveness. I am wondering what your thoughts are about the 2 yr lapse in being together. I was told that our girl was less confident “back in the day” compared to her sister but has obviously gained confidence with us. I want to rescue this sweet dog but not at the expense of my girls well being. Any thoughts?

  139. We raised two springer spaniel siblings together from when they were pups and they have had a wonderful life together with no issues (until recently). It has been great because they have kept each other company when we’ve been at work. They are now 12 years old and they are starting to fight with each other fairly often. I’ve been doing some reading, and it sounds like this is common. Our boy (the alpha) has had surgery on both of his back knees which has slowed him down tremendously. And although our female is mostly blind, she has started trying to take charge. When they were young they maybe had a tussle with each other once a year. Now it is at least once a week, maybe even more often. This is breaking our hearts. Is there anything we can do?

  140. We rescued 2 golden labs at 6 weeks and can tell you they were the biggest joy to our lives. We never had any experiences as the article suggest. They loved us, people and other dogs. The female just died this week at only 6 years old. We are very worried now because the male is very sad and not himself.

    1. As the article clearly states, not all pairs have these problems, and the issues are less likely with a male/female pair. Your dog is going through grief, but dogs are resilient and he will recover.

      1. Mr. Stallings, I understand that you apparantly have a degree with, but I feel it is so generic to say that “dogs” are resilient. Not every breed is the same and not every dog in the same breed is the same. 6 out of the 7 Basset Hounds we have are blood related and our 5 month old is blood related to all 6, but everyone of them is different. When my 2 year old Cardigan Welsh Corgi died after I moved out and was unable to take her with me to my apartment leaving her to the only home she had known; I had an autopsy done because she was doctored regularly and had all her vaccines, took her heartworm preventative, etc. and I could not understand why she would have just died. There was no physiological reason; according to the autopsy for my dog to have died and the only thing my vet. could figure out is she greived herself to death for me.
        Yes dogs “can be” resilient, but not everything is textbook and not all advice will apply to all owners, breeders, breeds, dogs and even illnesses. And I don’t have limited experience; as my veternarian said to me while getting one of my litters shots; ” You probably know more about whelping a litter than I do.”

        1. I’ll be the first person to tell you that not all dogs are the same, very much the opposite. And I do not generalize breed behavior because there is as much variability in innate behavior within a breed as across them all, not to mention mutts (my preferred “breed”.

  141. I am heartbroken. I found this article while searching for a solution to our problems. We rescued 2
    Black Mouth Cur brothers at about 12 weeks of age. They are now 7 months old and the issues are getting worse. They cower from people, noise and us, acting as if we beat them. We cannot control them outside unless they’re leashed because they will take off and act like they don’t see or hear us calling. As much as they adore each other, they’ll attack one another for food or a toy-to the point I believe they’d do serious harm if we let them “fight it out”.

    We previously had 2 littermate Golden Retrievers, male and female, and had no problems in the 12 years they lived. Just hearing about this issue now makes me so sad and also frustrated with the rescue shelter we purchased them from.

    Thank you for the article, advise and knowledge. I’m not sure what our future holds with these two but I have a feeling it won’t be pleasant.

  142. We have 2 female litter mates aged 4. 1 is a chihuahua / schnauzer mix and the other a lhasa apso mix. The chihuahua mix bullies the other in the form of growling and attacking in relation to food, playing fetch, territory and basically any other times she wants something. We were not aware of litter mate syndrome until recent research. The fights are easy to break up and can be done so before anything serious happens however I am worried about how far it may escalate when we are not around. Do you have any advice? Is it too late for separate feeding and walking etc? Both dogs are very loving and affectionate to humans and to each other but the aggressive bullying is a concern.

  143. I came across your article while trying to search for the closest answer to our problem (since (couldn’t find exactly what I was looking for). Last month we adopted a 3-4 year old rottweiler and her 7 month old ‘puppy’ that looks part scottie (the previous owner said this was her puppy). I actually adopted them from the pound (Michigan) together because I didn’t think they should be adopted separately, they are so bonded. The little one is so attached to her mother that she won’t eat from her bowl until the mom is done. Letting them outside to do their business, the little one won’t leave the mom’s side, and even after several hours will come back in the house and pee! I am gathering from your article that it is very important to start separating them daily, even for a short time, so that the little one knows it is ok to be on her own. Will this even work at this stage? I am really mad at myself for not starting this process when we adopted them a month ago, as the pup has only gotten more attached this past month; I just didn’t think a lot of changes would be good right away (as it was their 2nd time being at the pound within 2 months). I would really appreciate any insight I could get. Thank you, in advance, for pointing me in the right direction!

    1. The tight bond and lack of confidence in the pup could be a similar situation to littermate syndrome. I think you should seek out a trainer or veterinary behaviorist in your area to evaluate.

  144. Jeff, I came across your article in a fashion very similar to Elizabeth’s. I was searching online for a reason two dogs from the same litter fight so often and so viciously. My two dogs, German Shepard-Husky mixes, are brothers who are just over 3 years old. About 1.5-2 years ago, they began fighting very badly, for no apparent reason. When they were younger, they, of course, would “fight” playfully, but never to an extent that caused harm or human intervention. The first time they got into a nasty fight surprised myself, and everyone in the house, since nothing like this ever happened before. We don’t know what started it and don’t know how to resolve it. We kennel them separately, and let them outside separately as well. The smaller of our two dogs, named Saber, usually is almost always the aggressor. While the larger of the two, Bentley, almost never makes an attempt to fight back. Even if the two pass each other, Saber begins a vicious snarling sound at Bentley and will sometimes even attempt to snap his jaws at him. Coincidentally, Saber is also very territorial. If someone, who does not live in our house or who he is not familiar with, approaches his kennel, he will bark and bark sometimes very aggressively. Also, Saber exhibits signs of separation anxiety. If he’s left alone for too long, he will begin to bark and whimper. Lastly, he also begins to bark whenever someone enters the room, no matter who it is, and won’t stop until petted. There’s no possibility for letting one of these dogs go to another home, as we love these dogs to no end. Are there any solutions/training methods you could suggest in order to help eliminate this problem?

  145. I’ve also never heard of this. I rescued a dog who ended up being pregnant and am keeping her and her two girls. They’re 4 1/2 months old and love playing with other dogs at the park, love my husband and I and are very sweet girls. One of them was supposed to go to my cousin but we decided that we couldn’t separate them anymore because of how close they are. I don’t want this blog to freak people out from buying/adopting siblings together. In my case, it’s been the best experience.

    1. I DO want to have people THINK! Read through the comments. This is a real phenomenon. Your puppies are only 4 1/2 months old so you can do the right things to avoid it. But please don’t pretend that you know everything about this when so many behavior experts have seen this time and again advise against it!

  146. We adopted two litter mates from a shelter at 7 months old. They are now 4, and are great together, but they do attack each other (nip at and jump at each other) when I walk them and they encounter any nearby dogs, even if the dogs are in their yard. One is worse than the other and whines when he hears something. When they do this, I’ve been making them stop and sit until I fell they are calm enough to go on, usually outside the yard where the other dogs are. Is this okay? I’m trying to desensitize them but don’t know if this will even work after reading your article. I know they need to be socialized, but frankly, I’m a bit nervous about how they will act around so many other dogs. I can’t take them to the dog park – already had 2 issues there. Should I take them to obedience school one at a time, even if they freak out when they are apart? I found a great trainer that gave us a personal lesson at our home, and they were amazing with him. The obedience class is a 45 minute drive off the mountain I live on though, so I’m hesitant to drive down with them separately. What do you think? I will start walking them separately though. Thank you.

  147. I have 3 siblings left from a litter of German Shorthaired Pointers- one female we are keeping and two males that we will train and sell as started hunting dogs at 6 months old. They must learn to crate quietly and separately (they are crated in my livingroom). They must learn basic obedience commands and respect their handler. They must be quiet and wait patiently while the other dogs are being trained within view. They must respect other dogs and work together harmoniously. They are 14 weeks old and are just starting this self-control training all hunting dogs must have. They have good role models- their mom and our other two dogs (elderly rottweiler and german shepherd). I expect manners from all the dogs and they clearly understand the rules- I highly reward good behavior and we have a great deal of fun together as a group, but the dogs learn what lines they cannot cross. I think trouble comes when you have high-drive, dominant, and/or aggressive dogs (especially if you try to raise multiple females or multiple males together). GSPs can be high-drive and dominant, but I am confidant in my ability to train them to accept leadership, work together respectfully in the field, and be calm at home. One of my puppy-buyers is considering taking a sibling as well (he bought one at 10 weeks and is thinking about getting another after the preliminary puppy training is done)- this can work well for hunting dogs if they are trained correctly (two well-trained, bonded GSPs will back each other and can be really fun to hunt with). He has his dogs professionally trained for the field (beyond the basic puppy field training that I do), so it might work in his case and the time at the training kennel will provide enough separate training and socialization that adverse behaviors might be avoided. A person does need to know what they are getting into, though, and be committed to doing whatever is necessary to produce a good canine citizen.

  148. We adopted a female husky/yellow lab puppy 22 months ago. The owner of the husky dad and lab mom kept two of the puppies. Our female has been great. She loves everyone and socialized at a very early age. She took puppy training classes and is great. She does have some confinement anxiety issues which prevents us from boarding her, but she is perfectly sane the rest of the time. We got a call a week ago from the host family asking if we would take the female sister of our dog because the family is going through serious health issues and cannot keep three dogs anymore.
    We brought the sister home a week ago and she is so sweet. My female is so excited to have another dog around, yet I am not sure that the new female was socialized in the same way my dog was. I am sure that her socialization was just with her mom, dad and sibling brother.
    So, I am now wondering, will this work? Do they know they are sisters? There are times when I think they do. The new female is very anxious and follows me everywhere. She seems a little stressed out. My female wants to play, and when they have run and played, the new female is showing some aggression and mouthing which I think is a little unsettling. My female keeps coming back for more, but I think the new female wants to be the dominant one. What are your suggestions? I am thinking about getting the new female into a doggie training class starting in two weeks. I have searched this site for any similarities in my situation, but none so far. Will they have the littermate syndrome as time goes on?

    1. NO! If they have issues, it has nothing to do with littermate syndrome…which only happens (sometimes) with pups who remain together as young puppies and into early adolescence. You can reunited older dogs who a siblings and you might encounter social problems between them, but not LS.

  149. I now have my female Doberman’s brother at eleven months of age. The previous owner is my son’s friend, and he sadly ignored the male’s solicitation needs, and subjected him to physical punishment for “puppy peeing” and acting,”wimpy”. In other words, abuse. Our Zelda, was raised well and is all a Doberman female should be. My son took them both on frequent outings and playdates together, so they remained ‘best friends’ but haven’t lived together, since the breeder’s. Now, I feel Zeus depending upon Zelda, a bit. He’s afraid of the leash, so when Zelda goes for her walks he TOTALLY FREAKS out! Crying, MOANING, burying his head in my lap, etc. However, every day he is better, and happier. He no longer crouches and pees upon seeing a male human, and let’s Zelda leave without carrying on. Any suggestions for this poor guy? Yes so beautiful and well mannered, and just wants us to love him. Ps, when my son returns from his job, in two months, he will take Zelda. Will Zeus be ok, if he finally feels at home here? Thank you,so much for your site, and reading this, Cynthia Crowley

  150. We adopted a sweet Catahoula about two months ago (he is just short of five months now) and now have an opportunity to help out one of his littermates. Homeboy, our current pup, had a deaf brother called Charlie. Charlie went to a home whom had a deaf dog before and had a very successful experience. Unfortunately, the family that took Charlie also had a new born baby and it ended up being too much to deal with so he was returned to the breeder. We see the breeder twice a week (they are also family) and were heartbroken to see that Charlie was returned. We are considering bring Charlie into our family but obviously, we want what’s best for the pups.

    They have spent the last three months apart and have both experience positive socialization with humans and other breeds. Each clearly have their own individualities as well. Do you believe that the separation in those first 4 months of life could prove to avoid some of the issues that occur with littermates?? Or should we still consider this a “high risk” pairing?

      1. This is wonderful to hear! Would you still suggest following some of the “procedures” you would with puppies who have grown up together during the socialization period (separate walks, sleeping areas, training, ect)? Or will the dogs react to being reunited as just two separate dogs, not littermates?

  151. DO some walks together, some separate. Same with training. I would tell you this even if they were not siblings. Training is easier one-on-one, adding in distractions (another dog, for example) as they get older.

    1. This is great. We really needed to hear this to feel confidant that this would be a good thing for both Homie and Charlie.

      Thank you!

  152. Me and my roomate decided to buy Huskys from the same group. They will be raised on one home, but each will have her own owner, bedroom, etc. If we really push separation and strict training early on, will this problem be mostly avoided?

  153. Hi I just got told my dogs ha e this but I’m not so confident I have 2 american bulldog x staffies brother and sister same litter both have been done so no babies there going to be 2 in September and my boy has started attacking my girl but only when someone knocks on my door I got her octo 2013 and rescued him Feb 2014 his a lovely dog they get on well play fine have there play fights which is playing as I call them and they stop but its the attacking her when there’s a knock at the door as soon as I tell him to get out his No’s I’m not happy I lovey dogs and don’t want to get rid of either is there anyway of sorting this please thanks

  154. Could this happen with puppies from different litter brought together at the age of about 8-9 weeks?

  155. We rescued/adopted 2 female lab mixes in decmeber, they arrive to us at just 8 weeks old.
    And like most humans, we adopted 2 so they would never get lonely.
    For the most part they are pretty well trained, within the first 3 weeks of getting them there were no more messes in the house, at all. They were taught not to chew on the furniture, and they do not, and they come when called and sit. These were our main training goals, we are all for lay rolling over and tricks.
    They are a little over 9 months old now, and about a month ago they got into a fight with each other, and one was brought to the vet for a minor wound.
    Never heard of littermate syndrome until I started researched female sister fights on the interent, that same night.
    Nevertheless, all my hours of research that night was not the most pleasant. I was angry, sad, and felt so stupid that with all the research we did before getting them, we did not know about this.
    I started immediatly following training tecniques that I had found, and started crating seperately, feeding seperately, bring them places seperately, walking seperately, individualized attention sessions, having them go outside in their yard at individual times, and also, showing the dominant one that she is dominant, by, giving her a treat first, feeding her first, petting her first, letting her out first, doing everythign that i have read.
    One sister is definately more confident than the other, and the submissive one, only always aims to please me and her family. I have made myself known as the pack leader/boss. There have no signs of aggression towards strangers or our family, which consists of my husband, myself, and our two children 11 and 8.
    I have always noticed that the dominant one will try and take a toy away from her sister, and the dominant one will start the rough playing.
    They are crated during the day seperatly while we are work and school, and they sleep with my husband and i, in our bedroom. We did not crate them at night due to the fact they were crated during the day, I believed that is too much crate time, and we do not have animals to crate them.
    Like I said I have just started everything recommended training wise for sister littermates at 9 months old.
    Do you think its too late for them or are they young enough to reverse the damage we have already done?

  156. I have a litter of Great Dane puppies. A woman is interested in 2 puppies. I would normally not do this but one of the puppies is deaf AND blind. Would having a sibling with him make life easier for him? They also have an adult dane in the home.

  157. We have Mini Aussie sisters that are 9 years old. When they were puppies and we took them for obedience training, we were told we would have trouble and should re-home one of them. But they love each other, groom each other, and still even play together, chasing each other around the room or yard like puppies. But they are each their own dog. Katie has bonded more with me, and Jessie is more my husband’s dog. Now and then they have a disagreement, but they don’t fight as much as I did with my brothers!

  158. I’ve got two springer spaniel girls that I’ve had from 9 weeks and they don’t exhibit these negative behaviors at all! I only learned that some were against adopting littermates after I posted about the pro’s of adopting siblings 🙂

      1. Yes, I read the article, and was only noting my experience… But based on many other’s comments, seems that mine may not be the exception!! Would be interesting to see some clinical research to back up… documenting breed specific behaviors, as well as the presence of marked behaviors as the result of irresposible owners!

  159. I wrote this on a dog forum so it may look sort of off in this reply. But basically, it’s describing what I did with my two toy Poodle puppies I got from a reputable show breeder. They were from different litters however, but they were only 2 days apart in age.

    I don’t think this is a matter of a one-size formula for success fits all. Not in the individual dogs, the breed, the humans in the picture, the environment. I think there are so many factors and variables that any blanket statement to me, sounds like myth.

    I had two adult Chihuahuas at home when I brought home my two 8 week old puppies from a reputable breeder near by me. Two males, now 2 years old and intact. I would under no circumstances house two male Dobermans together. But Poodles…meh. No problems here.

    I talked with my breeder a little bit about these horror stories about not bonding well enough with the humans, and is it okay to get two males? etc etc…and he looked at me like I had two heads. “Where’d ya hear that? Nah…you won’t have any trouble with these Poodles. They have wonderful temperaments and they’re Poodles!” LOL. So, home I trudged with Matisse and my side-kick, Maurice. I wasn’t planning on two, but I couldn’t pass up Maurice.

    I had a nice ex pen for them and two crates. I still use my ex pen at times…like when I leave the house to go shopping or something and for day time naps.

    They spent a lot of time together, but some time apart. Being together kept them from crying at bed time (though they each slept in their own crate but next to each other) and when I’d leave the house, they were in the ex pen together…no problemo.

    They each, including my older dogs got their own walk and still do, though sometimes we all go out together. (I don’t have Chulita anymore so I’m down to 3) They each get their own training sessions, usually incorporated in their walk, but sometimes at other times during the day…little snatches here and there. Jose`, my Chi doesn’t really need much in the way of training but we do a little practice here and there for the fun of it.

    Matisse took handling class with me and we’d be gone for several hours once a week and we went to shows for days and Maurice stayed home with Jose` and my ex who watched them. No problem with that….no separation anxiety or anything.

    I use to take them often, one at a time to a pet store, Home Depot or some such place where they could socialize and just be with me.

    But they did spend plenty of time together and still do. They spend more time together than separate now.

    They took a lot of time and tons of supervision…lots of work. In some ways though, it was easier having the two of them, as they kept each other company too when I was busy or something. They felt very secure when left alone until they learned they could cope all alone for short periods so it eased them into things like that.

    This is how they are now at 2: They’re both crazy about me and each other. They get in minor squabbles now and then over a toy or some such nonsense but quickly get over it. They obey me quite well. They can be called off of the distraction of each other while playing if I need one to come to me for something. If they’re out in the field playing and chasing, if I call one, he or both will come. So they definitely don’t ignore me unless we’re talking about some distraction that they’re just not ready for in their training. But it’s not about each other that is the distraction. If I go upstairs, one might follow me, the other might not. Matisse is more my shadow I’d say. Maurice is a tad more independent, at least in some ways.

    I do some training with all three of them at a time…there are some fun things to do that you can do that way. For instance, I’m teaching them all to stay back when I open the door and even when I walk out into the yard or hide around the corner. Little by little, they’re getting better at it. I do that with all of them together and separately. They totally pay attention to me…and have a ball together too.

    Here they are…the three of them (little Maurice is hard to see) learning to stay back behind the threshold of the door when I open it to go out, when I ring the bell and make a commotion and then go out…they pay attention and are very trainable. It doesn’t matter if they grew up together from 8 weeks of age or not. (no picture available here)

    I think it’s important to have some one on one time with each puppy. Plenty of training using progressive methods, some activities…going in the car someplace with each dog separately and then sometimes together too. I don’t think it’s nice to separate them a huge amount of time. They enjoy and entertain each other, learn from each other. It doesn’t mean they don’t like or bond with humans. I think that’s a myth…unless the puppies are neglected or not given adequate attention and training. Then naturally they’ll gravitate to each other. They are social creatures in a very big way. And they’re also designed to live and get along with humans by a convergent evolution with humans. So it shouldn’t be that hard as long as you’re prepared to put into them what you want to get out of them. Work smart, learn about operant training concepts and make sure you have a lot and I mean a lot of time on your hands. lol.

  160. I have had 4 litters of Basset Hound puppies since September 2014. All different mothers, but the same father. I have 2 families that took home 2 litter mates and 4 families that have brother/sister/cousins, in other words they took puppies from seperate litters but having the same father with the mothers being sisters; and yes I knew about this syndrome because 4 of the females I have are litter mates, went through it. When these 2 families expressed wanting 2 from the same litter, I absolutely informed them of the issues we went through with the four sisters; they still wanted to try. I have kept in contact with all of the forever families that have my puppies (29); only 2 have not responded back. And yes the 2 families are having some of these issues to various degress. I am monitioring the situations and advising them in the way that I know we were able to deal with it. The key thing we have found to be affective, is individual time with us. Getting on the floor and loving each one with no other dog in the room; re-assuring them of how much they are loved; it seems to have worked a great deal. Each sister has a favorite sister so they are paired together over night or while we are at work. Never more than 2 dogs together and the one sister who seemed to be the target by the other three is paired with our male who just seems to adore and protect her. It does take work; and if you are not able or willing to put in the effort than by all means for the safety and well being re-homing is probably the way to go. The other 4 families with 2 puppies from different litters don’t seem to be experiencing the issues mentioned in the article; which really does confirm the existance of the syndrome. It is real; can be really horrifying to see and I even have scars from breaking up a pack fight, not bites, but cuts from falling on the concrete or ice and snow. I was beside myself the first time I saw this. I am a former registered AKC breeder and member of the Cardigan Welsh Corgi Club of American; had 3 sibling litter mates and never saw this behavior, but my Basset Hounds are another story. Needless to say there are no toys with certain dogs in the same room and there are no longer rawhides given out; both are generally a catalyst for a fight. If you are fortunate enough to get a puppy from someone and they are a great puppy; consider waiting to get another puppy even from the same parents from another litter rather than litter mates.

  161. Jeff – I was wondering if any of your research indicated that the syndrome could be at all mitigated by having one of the siblings “foster homed” with another family for the first month or so. For example we keep one of the 8-week old puppies (the less dominate one) in our house while our relatives keep the other 8-week old puppy (more naturally dominate and slightly standoffish) for about four weeks or so – with the thought being that both will then learn what it’s like to be alone and separate from the litter. Then after about four weeks bring the other puppy from our relatives’ home to ours. The situation I’m describing would be for two male English Mastiffs. Based on your research do you think this would have any impact at all toward minimizing the chances of the syndrome developing?

    1. “Research” would be overstating the case. I based my article on my subjective observations and that of highly-regarded experts, namely Nicole Wilde and Ian Dunbar. That said, your plan is good and I’ve seen it work, but I would make it 8 or 9 months, not just 4 weeks.

  162. Jeff-
    I have just taken a female and male morkie home. One is for my daughter, the other one is for me. They are only 8 weeks old, but they are constantly play-fighting with each other. The girl usually initiates it, but she will then roll over and let the male dog win. There is constant yelping, growling, and chasing. The male dog listens to my daughter, but we cannot get the female to listen to anyone. Are we on a track of littermate syndrome? If they are fighting now, will it get worse as they get older? We have enough space to keep the puppies apart, but my daughter and I both work during the weekdays and I am now afriad to leave them home alone in their play-pen together.

    Do you have any suggestions?

    1. My littermates still play fight and also bathe each other and sleep together. They’re 10 months old now and are still doing fine. I’m glad I kept them both.

  163. Hello! This article was very informative, but I’m still unsure of what to do in my own situation. I have two female boxer siblings, five months old, and they are exhibiting some of the symptoms in this article. They hate to be separated, and haven’t been since we adopted them. Even when walking them both, they are reluctant to split up if we take them in different directions. When eating, they refuse to eat out of separate bowls, and will actively try to shove each other out of the way to get at the food. Even with two bowls down, they try to take what the other has. They love to meet new people and dogs, and are very affectionate, so I’m not very worried about them becoming antisocial. However, I don’t know how to go about separating them because one is deaf. We strongly suspect that she uses her sister as a guide at times, and makes decisions and reactions based on the way her sister acts. We also believe that her deafness causes her to feel vulnerable- thus she can’t stand to be separated. What should I do in this situation? They need to experience separation, but they both panic when it happens.

  164. I have two 10 month old pitbull/terrier sisters. I had never heard of this syndrome before yesterday, and it makes so much sense! They’re not aggressive toward each other, although they are constantly play fighting. One definitely is the dominant one, though, and it’s starting to affect her relationships with my other pets (I have three other dogs and two cats). Before recently she was fine around them, but she’s started acting out. She is great with people but she does very poorly meeting new dogs.
    I do crate them separately, but I was wondering if you could give me some tips for increasing their training. I’m hoping that since they’re still relatively young, I could fix it if I alter our habits now. Any suggestions?

  165. Would it make a difference if you adopt one sibling at 7 weeks and find out the other sibling needs a new home at almost 4 months of age? Sibling #2 has been at home with the parents. Sibling #1 has been in our home as an only dog. (well he has 2 cat sibs, if they count 🙂 )

  166. Does littermate syndrome only apply to puppies coming from the same litter? Or could it also occur if you were to get another puppy who’s parents are the same, but born at a later date.

  167. I cannot tell you how impactful this article has been to me and my brother-sister boxer puppies. We’ve had them in our home since they were 3 1/2 months old (now 5 months) and we’ve had attachment issues from the onset. We seriously thought they may have been neglected or abused by the breeder. They currently exhibit every symptom you discuss in this article, the female more so than the male. My kids have been very hesitant to re-home one of them until they read this article. Fortunately for us, my brother and his wife are eager to take the female, so we won’t loose contact with her completely. I feel so foolish for not researching this further before diving in to litter mates.

  168. In reading this im a little worried about my two puppies i got. They are 12 week old littermates mix bread. They so fight but do well in socialization class. So we are thinking of seperating them in the house
    My question is how long per day and how long we should till they dont have to be seperated for long periods of time.

  169. I have sibling sisters 12 weeks old, that fight some but do well in socialization classes
    They will bark and growel over high value chew toys sometimes. After reading this we are going to seperate them in the home
    My question is how many hours a day should they be seperated, and how long to we continue seprerating them for?

    1. I raised two girls from day one when my rescued dog was pregnant. They acted like normal litter mates and would play fight, and still do at a year old. They love each other so much and also bathe each other. Hope yours turn out the same.

    2. I would recommend that they are separated nightly and that they are crated separately when you are not at home. Get them spayed because their heat cycle will cause them to fight. Make sure that they are not running your household. A good exercise to do with them is to make them wait for food and wait to be walked. Don’t feed them until they are both sitting quietly and waiting patiently for their food. Same with the door. Don’t open it to let them out until they wait for you (leashed or unleashed). If they are sitting but are shaking or sitting and getting up when you go to open the door, close the do and wait until they sit patiently. This is not an easy task especially with hyperactive breeds, but it is vital in developing yourself as their pack leader. Just be calm and assertive during these activities. It doesn’t take a lot of talking either. If you can’t seem to manage to get them to listen to you and establish yourself as their pack leader, I highly recommend that you rehome one for sure because one of them will take that position and the other may end up being bullied. Some dogs that are forced to become the pack leader are forced out of their natural beta roles and these dogs are usually the ones that take things too far and generally give their owners behavioral issues that are unwanted.

      Sibling syndrome can easily be avoided with the proper handling and socialization of your puppies. But do it sooner rather than later. Your socialization window for these girls will end once they reach 16 weeks old. It’s important to treat them as individuals and train them separately and then together. The most important command to learn is the “come” command. It keeps them from loads of trouble if they learn that coming to you is more valuable than anything else they find to grab their attention in the world (even each other). So basically you have to be more valuable to them than they are to each other. Have them interact with other dogs individually. It will help them develop their socialization skills and they will not be as dependent on one another. I know it sounds like a lot of work, but owning a dog is a lot of work and being a good dog owner means you are working with your dog daily. You will just have a little more of a challenge, but it’s just double the love and companionship in the end.

  170. We just brought home two male lab puppies. So far we haven’t noticed anything alarming except one incident over a toy. Other than that the pups are on different sleep schedules; while one is up and playing the other is sleeping and then they just magically seem to switch. They sleep in different crates on opposites sides of our bedroom at night and when we take them out to walk we go in separate directions. One pup does cry when we do this at first, but it is becoming less frequent. They are both very curious when it comes to meeting new people. We’ve introduced them to a few dogs and only one seems to be fearful. I’m hoping they won’t become dependent on one another if we continue with this current routine.

  171. Great article, thanks! What do you think of this scenario? We have an entire cockerspaniel family living together. The father is 8 years old, mother about 2 and the 7 siblings are now 7 months old. The parents live in the house with us and are very well behaved, the puppies have been living in the garden and have their own big doghouse where all can fit well. We feed the puppies and parents separately but all the puppies together from 2 or 3 bowls. We see no levels of agression yet and despite there being a hierarchy we do not feel that the dogs are intimidated by each other, other dogs or humans. They play with kids and our 5 year old son. Every night one of the puppies (randomly) is taken into our bedroom to sleep with the parents and there seems to be no separation anxiety. The dogs have a vast space within the limits of the property and are taken on walks in parks and in the city two by two, frequently.
    Now the question is, should we expect all of the horrible things you and others describe to start happening to us, only on an even worse scale and when and which dogs should we castrate? Currently only the mother has been spayed after giving birth. Both parents seem to be playing a vital part in the developing of the puppies and the pack hierarchy. Thanks and regards! P.S. We do not live in an english-speaking country.

  172. Wow! I have two male doxie siblings since they were two months old. I had never heard of littermate syndrome. My dogs don’t fight each other and get along fine with both other dogs and cats. They also love people. They are going to be eight years old in july. I guess I was lucky..,!!

    1. I think Dachsunds do get along well with other Dachsunds. Can’t find information to support that though. I am an experienced dog owner and the breeder allowed me to get my current dachshund brothers right after they were weaned. Everything is great. I would be interested in hearing from people that have had bad experiences with Dachshund “littermates”.

  173. I had never heard of this before, and now I’m grateful for not having to experience it. We have a pair of husky/mal male litter-mates. We’ve had them since 5 weeks of age and they are two and half years old now. We had no problems training them…which we did sometimes together, sometimes separate, they get along…never fighting, except the normal roughhouse play.

    We did have an older female husky when we first brought them home, up until last year when she passed. When they were little we kept them in separate crates in separate rooms (one is sort of our sons) at night. Now they sometimes sleep in the same room, sometimes not. I walk them separately, because there’s no way I can walk two big dogs together, and they are fine when the other is gone…although they do a get a bit of separation anxiety when one or the other is gone too long. They are very close to each other, but are also very close to us….their litter-bond didn’t hinder them in bonding with us.

    I am glad we have been fortunate in not having to deal with the behavior problems that can stem from adopting litter-mates. Something I didn’t know about until now, but will definitely keep in mind.

  174. Question kind of related.. I bought my Yorkshire terrier about 6 years ago, and my mom decided to buy his brother from the same litter, they love each other. Sleep in the same kennel, go everywhere together Ect. I got married and my husband and I want to take my dog. I’m worried that he will get depressed. Would it help if we bought another dog to keep him company? Or would that make things worse or harder for him? Thanks in advanced!

  175. I have three littermate dogs I’ve raised since birth. I had their father and mother but both the father and mother passed away. The three littermates get along and have never fought. They are pure bred american pitbull terrier. Their genders are two males and one female. The female is timid towards strangers in public. She is aggressive towards strangers at home.The males are not timid or show no aggression in public but both show aggression towards strangers at home. They all have thier own dog areas. I allow them to play together but not every day. I allow all three to play together and i am proud to say there has never been a incident. They are currently 22 months of age and the female has never been bred. Both males have cross bred to different females and have produced offsprings. Note: I seperated them at 10 weeks of age.

  176. Hi Jeff, I’m in a terrible situation. We adopted boy/girl siblings a year ago. They are Germam Shepherd Lab mix. They play together and rough-house but nothing too aggressive. The problem is when we took them to be trained, they went crazy without each other, even for a minute. When we go to the dogpark, they snap at other dogs trying to protect us and each other. In public, they cling to us and each other. When we leave them outside during the day, they bark incessantly. Then we left them inside for the day and tore up everything in sight. Then we left them in their separate crates inside they cried all day. Bottom line –when we are at home, things are ok. When we go out or leave them alone, it’s a disaster.
    It got so bad (for many different reasons), we put them up for adoption on social media with no takers then eventually surrendered them to a no-kill shelter. We are heartbroken.
    I called the shelter to see how they were doing. Many people have shown interest but they show “fearful aggression” towards people who want to pet them. They are keeping them in the same kennel because they go crazy if they are separated.
    I feel this is all my fault. I’m worried that surrendering them made them worse. We are so sad and feel horrible that we couldn’t deal with them – leaving the shelter to handle them. I want to go and reclaim them and bring them home because no one will adopt them. It’s only been a week since surrendering them and I feel terrible. What should I do?

    1. I think you shouldn’t have left them in a shelter and seeked further assistants or training for them.
      They probably don’t understand why they were left and will probably cling to each other more.
      Sorry, I’m not an expert but maybe you should get them back before they are separated and seek further advice.
      If they were your children you wouldn’t be allowed to just give them up.

  177. Dont agree…i crate them together during day…at night separate…they play together..have older dog and cat in household…that are in room with them and dont have problem. Playing sometimes gets crazy and one usually yelps but right back together. They dont have problem with one in crate and other one out. I think it depends on the owners and how much time they spend with them….Im there everyday but one and dont leave them unsupervised just like you do children. You teach them as they go…So I disagree and this is third pair of littermates I have raised.

  178. We have just taken on two golden doodle littermates (sisters) unaware of littermate syndrome till I Googled their behaviour. During their playtime they fight constantly and vocally . We have had them for less than a week, is this something that will correct with the tips you have given? Thanks

    1. Bethany,
      Although I am not a dog psychologist nor do I have any letters after my name I do have plenty of personal experience in this matter. The tips that Jeff suggest should help and time is key.
      I have eight Bassets Hounds; and 8 y/o female, four of her daughters (all litter mates) that are now 5 y/o, an unrelated male, a 1y/o female that is the offspring of our male and one of the daughters, and a 7 month old male the offspring of our male and a different daughter.

      When the daughters started coming into heat they became aggressive toward each other to a point where 3 would gang up on one and one time even their mother. We were at our wits end. I had bred Cardigan Welsh Corgis before and had kept 3 from the litter and did not experience this. As they matured and also realized we humans were not going to tolerate this behavior they have ceased this behavior. Walking them separately helps, feeding them separately, playing with them separately all of these things will also help, but above all, spay them ASAP. This will help to tame their aggression and their natural instinct to fight for their position in the pack.

      Now none of the sisters show aggression toward the two youngest and have been told if they do they are gone or no more, but it was not going to be acceptable.

      If you are not willing; nor if you don’t have the time it will take… cut to the chase and re-home one of them now before you become too attached to both; that is if your aren’t already. The four daughters that we kept were born here and we whelped them. After we had them for about 12 months and height of this behavior brought us to true concern we tried to come to terms with re-homing three of them and we just could not decide who to re-home. Our girls are not spay (will be soon) they have all had a litter and two of them have had 2 litters.

      We have whelped, raised, loved and cared for 52 Basset Hound puppies since 2011. Litter mates start to fight anywhere from 3-5 weeks old. Their early development is a key to how they will behave. We have taken different approaches with each litter; based on what we have learned from the previous. We have always loved and handled them, but at first waited until they were 3-5 weeks old. We have found that handling the puppies and hand feeding them really helps them to develop into loving and loyal pets. Know what you want and work for it..

  179. I have two dogs who are brother and sister. The boy who we’ve had since he was about six months old and is a joy to be around. He’s always happy. The girl is completely opposite. She acts very depressed. If you try to play with her she’ll go lay in her crate. They did not grow up together, we just got her about two years ago from an owner who didn’t want her anymore. They kept her crated a lot. I wonder if that had anything to do with her personality. She’s still a very sweet dog, but very timid. I would like to break her out of her shell. I guess dog siblings can be complete opposites like people can be.

  180. I didn’t read all of the posts, but I like the many that I read. I don’t think that proper attention is given to breed type when discussing litter-mate syndrome. From my experience, dachshunds can do very well in a pair. I purchased two six week old male dachshunds (different litters) two years ago. They are wonderful pals and family members. They slept in my bed from day 1, usually one one each side. I can’t imagine a better situation. They are individuals, but love their pack (which includes 2 cats and 5 humans). I love it.

    1. One follow-up. I think that littermate syndrome would not be an issue with many dog breeds if the humans give the dogs enough direction and love. Since most people work for a living, they cannot provide enough of either and therefore should only get one dog (or even none). I am retired, live in a small house, and am constantly around my animals. For people who are good with dogs and have plenty of free time, littermate syndrome should be the exception.

  181. I was not aware of this problem and have two sibling labs, a male and a femaele. The male is dominant over his sister but we also have a 10 year old female lab who is dominant over both the younger dogs. I guess having the older dog prior to getting the siblings prevented most of the problems. But we do have fear of strangers in both dogs and separation in the female when the male leaves the home. The male has no separation anxiety. They are three years old now and do not play rough, but they did play very aggressively as puppies. The fear seems to be getting better as they are getting older. I’m hoping with more separation, socializiation and more obedience training they will do better. They are very well bonded to all family members. The show no aggression with other dogs at the dog park except for fear as we approach the fence, but once they are inside they are fine and get along quite well with other dogs. Any advice appreciated.

  182. We adopted two border collie pups..sisters. Fine w company. Play together well. And get along fine w company but every so often a viscious fight breaks out. How do we correct this? Love both of them.

    1. Hi Nadine

      You have received copious info on the topic of siblings, littermates and the pros and cons – all variable due to variable personality factors that are often unknown in the beginning.

      I am a physician and mother of children and mother of multi sibs boy dogs, with lots of formal psych training, but the more valuable hands on life experience knowledge. Will sum it up this way:

      We adopted 2 male white shepherds (and the particular blood line I got this time is more wolfy wild than others in temperament) – one turning out very alpha and the other the runt – more middle dog personality, but would usually capitulate to the rule of the alpha. They love each other unreservedly (groom each other like cats, sleep with their heads draped over each other or me). But, occasionally, there has been a flare that has escalated to a full fledged fight – which I break up. Grab them by the scruffs of their necks and then timeouts in their indoor kennels which are side by side.

      It’s no different than raising multiple children (boys, girls or mixed). There will be scuffles and very occasionally challenges. They are just 3 yrs old now and I can count only 3 of the truly serious challenges.

      After a reasonable timeout – they are back to their former darling loving selves. People have multiple children and deal with the same issue. Group dynamics seek their own levels and negotiate positions and behaviours. Dogs are no different than human toddlers. They must be taught the rules, use of familiarity, consistency, love and kindness but firmness. It is no easier being a dog owner of baby and adolescent dogs than a parent to same. Too often people think that dogs come with more built in ‘pet behaviour’ script. If you can discern what the fight was about (only one toy available) and it can be remedied – great. But, if it is over time with you or a food dish (though the other is the same) then a timeout in their kennels teaching them that this behaviour won’t do. They’ll figure it out – but if they are very young – may take many timeouts – but they will figure it out.

      I wouldn’t worry that your adopted Border Collie pups had a fight. This is the smartest of all breeds and can be taught so very much. They will have to be supervised for a good long while, as they learn the rules and adjust to each other. Then you can let your guard down some and later you will all just lounge around together. Believe me on this — is the way nature planned it and is what my husband and I have both experienced separately and together as parents of various mammals – including human. Do keep in mind that the dog’s brain processes more simply than human adults (about the same as young children) in that they have very little frontal lobe activity – no abstract thinking – no forward planning – far less able to connect all the dots — which is why they are also usually very happy and loyal. They are incapable of spite or guile. They are innocent, just like young children. But, they do feel genuine emotion and love and need security and reassurance.

      Please hang in there – even though you might have those moments. Just be a confident, kind, but consistent and firm mother. You’ll love having the two!

      ps – I suckered in for adding a 3rd male – 18 months old to my 2, 3 y/o boys – and each boy had 3 days one on one with new boy and loved him. My initial worry was that they might gang up on him. Not at all what happened. When I went to retrieve 1st dog – everyone played nicely for the evening.
      Later when lounging by the TV – alpha dog wanted to attend to new boy who was on leash to protect him – and number 2 brother dog joined in. No deal – alpha dog wanted nothing to do with brother. They fought over new boy. This went to a kennel time out for brothers a few times. Now seems to be going smoothly – but won’t ever leave them completely unsupervised for many reasons. Don’t want my home wrecked. lol There will no doubt be challenges in the future – as with kids – but same action- discipline (means teaching originally from the word disciple – which is student)

  183. Thank u so much for your article it is so what I’m dealing with it I have a horse rescue and was working with a client and she had told me that her neighbor had lost their home and left there dogs to die and they started taking down deer and eating road kill to survive and she thought the female was pregnant I got the female and was going back for the boys the next day and someone called the police and they killed the dogs so sad but she had her puppies in my living room and we were able to rehome mom and 4 of the pups but the other 6 are with me we are having a hell of a time they are now going to be 5 years old in March and we have had fights on and off and it is getting to be to much the females can’t go together at all they are not done with their fight so they are separated but now the boys are getting into fights it’s our fault with having so many we couldn’t separate them and then if we did they would fight through the cages with cage aggression we put them in different rooms and then when u bring them back its fine for everyone for months and then the boys will get into it again I don’t know what to do anymore I’m at a loss if I get rid of them they will be put down they are really good dogs just have there times where out of no where they explode

  184. I have 2 Australian Shepherd / lab littermates. 1 male & female. 15 months old. I had not heard about any issues with this until recently. I came across an article. I haven’t had any of these issues. However, they were raised with 3 other dogs. All of our dogs are rescue or pound bound from friends. (Our hearts are too big, and there is no non-kill shelter around). We have a 8yr old lab female, a almost 2 yr old rott/husky female, and an 3? Year old Boxer male.
    So yes the pups are close they have been influenced by the other 3. I also am home almost all the time, have 3 teen boys and my husband. Kids are always in and out. We have a small wooded area on the river, but only have about 1 1/2 acres, which is plenty for them.
    From what I’ve heard we are the exception though.
    I’m not encouraging anyone to get littermates unless you have the right situation to pull it off. If I knew about these problems above and all the work I’ve done accidently I would never recommend it.

  185. I adopted litter mates and did not have an issue with the syndrome. HOWEVER, I was not a first time owner, it was a lot of hard work when they were puppies, and I dedicated enumerous amounts of time to them. I was younger and single when I brought them home. So, I had the time, energy and no other household distractions.

    I believe that having opposite sexes played a role. Too, I crate trained them in seperate crates, they were socialized, going to the dog park often and taking walks when they were pups. I also monitored them a lot early on. Additionally, starting off I kept one in the crate while i trained with the other until they started having consistency. Overall, I tried to create consistency in feeding, walking and potty breaks. These are all things that I think created a healthy mentality. In the long run, through all the hard work…times I wanted to give up; it payed off. They were both well adjusted, taking on their own little roles in the house.

    Unfortunately, one of my doggies got peritonitis at the age of 4 or 5, and she (sheeba) had to be put down. Thats was one of the biggest heart breaks. Thats a whole nother story, but brings me to the point that two dogs are expensive! Nonetheless, when Sheeba did not return, her litter mate, sly showed no signs of separation anxiety. I think I took it harder then him. But I also pushed through my sorrow and continued the dog park and walking routine. This may have helped him.

    I still have Sly. People may think I am crazy but he has been a true joy…my best doggy friend! He and I love to go for walks, he’s traveled with me…and is a very well manner dog.

    Long story short…litter mates are a handful. If you are a first time owner…dont do it! If you have A LOT OF TIME to DEDICATE, and patience then go for it! But you have been is must be vigilent and attentive…all the hard wotk does pay off!

  186. We have raised 2 female littermates for 6 yrs. We have a horrible fight once or twice a year. They went to puppy obedience training & we have had 4 different trainers. We just had a big fight today. We are heartbroken. It had been 1 1/2 yrs since our last fight. We never heard of this either until we were already in love with both of them. We want what’s best for the dogs. It’s just a horrific situation. Did I mention just how much we love them? We live in Norman Oklahoma.

  187. Do you see this same situation in puppies that are not littermates but are started at a new home at the same time? We have a deposit on a male Maremma puppy and a female KaraKachan puppy from the same breeder. They were born on the same day but have been maintained in separate areas on the farm. We will be putting them together once we receive them to start their bonding with our sheep flock (for their eventual jobs as Livestock Guardians).

  188. We have two Westie sisters. They have little tiffs once in a while over food. But generally, they are happy together. They both love human attention, but one of them wanted human attention right away, while the other was more dog-oriented for about six months. Socialization of both has been very good because they want to be good dogs, basically.

    We have always considered them lucky. If we are out of the house, they keep each other company. They lick each other’s ears.

  189. Raising two male littermate Maltese puppies. They are 4 months old . Brought them home at 9 weeks old. They were trained in the first few days in using the wee wee pad, have learned to sit and give their paws and seek attention and are loving to all family members. They sleep in separate crates for 8 hours a night. If I would have believed all that I had read, I would have been deterred from keeping them. They are a delight and with consistency and diligence it can be done.

  190. Hello, I’ve been training for about 12 years, and I’ve dealt with a few cases of what I’ve always called Sibling Syndrome. None that were ever too terribly extreme and generally singular training and separating for large parts of the day has worked. This morning I got a call that I’ve been expecting for quite some time. A friend of mine, against my advice, allowed a gift of two sibling puppies ( lab x APBT) for her young daughter (age 5) . There are three other teenagers in the house, and I could see that this was going to be very muddled in the way of training. She called this morning with a plea of assistance because they are becoming aggressive and fearful, unable to be walked or taken to the dog park. I have a feeling she isn’t going to like my advice.

    1. Wrong family and setting for sibs. Too chaotic. Don’t like these environments myself.

      My own situation defies all odds – but the truth is that has a lot to do with the ‘owner’ and her understanding of the canine and skill with them.

      My 2 white shepherds sibs (now 3.5 years) are so great and we added a white shepherd wolf mix rescue (soooo wasn’t planned). But, amazingly – has worked out just fine. Even the 2 mil house is surviving (which I never wanted pets in, let alone energetic shepherds). Boys worked out pecking orders and have a ball with each other. They are nearly perfect. Never imagined having any dogs let alone a pack of 3 whites (and one mixed with 60 % wolf).

      I can’t see the usual owner ever having what I have. I understand the more intense canine mind and responses, which I already had in my 2 older WGS – but way accentuated with new dog (scarey that it makes sense to me). Wolf-dog mixes are not to be taken lightly and really should not ever be marketed as a pet. Most people just wouldn’t begin to understand or cope. But, on the flip side – their high intelligence makes it so much fun – tho, have to keep that extra stubbornness and extreme adherence to hierarchy in mind at all times. Mine want to please me – so I have that going. When they need a time-out for barking at walkers or fighting in the house – I just command them to “kennel (their extra large crates they love) — go to kennel” and they all do.

      I can’t recommend the more spirited (or work type breed) dogs to most people – let alone sibs to the usual owner. I take mine out ‘one at a time’ in public so to keep control. I will never trust them with strangers. Again, most owners want a pet and either can’t go thru what I do or just wouldn’t want to. I didn’t bargain for it — but, like having special needs kids — you accommodate as you must — and I couldn’t imagine not having all of them. We’ve had wolf-dog for about 4 months now and is like he has always been with us.

      Enjoy your articles. dr. h

      On Sat, Feb 11, 2017 at 1:53 PM, Jeff Stallings, CPDT-KA wrote:

      > Juliet commented: “Hello, I’ve been training for about 12 years, and I’ve > dealt with a few cases of what I’ve always called Sibling Syndrome. None > that were ever too terribly extreme and generally singular training and > separating for large parts of the day has worked. This ” >

  191. We have Dachsund/Terrier mix siblings. 2 females. One is bigger than the other and is black/white. The smaller one is white/tan. We have taken them to dog parks and they interact with other dogs differently but friendly. We train them daily and Incorporated agility excercises. Being consistent is key. They love humans equally. No jealousy, no fighting. The Black/white dog is top dog. The White/tan dog is more stubborn. Both have been easy to train.

  192. I am experiencing this all too well right now with my two girls. In December of 2015 we got our girls (chihuahua/pitbull mixes). For the first 8 months or so everything was going great. But lately every time we give Harley attention (or even after we give Ivy attention) Ivy will attack Harley full force. We have had to take Ivy to the vet for stitches. When they start fighting it is impossible to distract them and breaking them up has caused us to get bitten as well. We have asked the vet for recommendation after recommendation. We have tried DAP with no success and now Ivy has been placed on anti-aggression medication. Its to the point now that when we put Harley down she goes immediately on the defense like she is anticipating her sister to pounce. Last night and this morning they got into again and now Ivy has some new cuts on her face. If they are left alone and we don’t try to touch either of them of them they seem fine, laying together and playing together and they share food great, but any type of affection shown to either of them now provokes something. Has anyone here had any success with correcting this behavior or managing a way to keep both pups in the home. I simply love them too much to see one of them go. The whole thing just makes me so sad. Any help would be greatly appreciated.

    1. Dogs do have well developed limbic systems (emotional centers) and do experience jealousy. We have a much less severe situation, but some jealousy for affection between our 3 white shepherd wolves. And, they do not have to be actual ‘littermates’. One of ours is an adopted wolf shepherd (was a rescue and would have been put down). You’d never know that he wasn’t part of the litter, though as they are all very tight.
      One in particular just won’t be denied. If either of the others is being given affection, he wedges himself into the mix and pushes the attended one out. A few times, they have all shown aggression toward each other if one has ‘claimed’ mama’s attention for himself. The supreme alpha dog is bothered the least just for projecting a supreme presence. However, the adopted shepherd and the beta do get into it over a variety of things. Each holds his own and blood and scarring hasn’t been a problem.
      Like with children — you’ve probably already tried this — but take both at the same time and reassure them as BOTH are given affection. Might need to perform exercises with help – where two people are engaging both dogs at the same time. The one who would show the aggression should be given a firm ‘NO’ to learn that that behaviour is not acceptable. As soon as she relents, then praise her for being a very good girl. This will take some repeating and consistency. Might need to take a more remedial step initially. When she shows the aggression — immediately take her to her crate (saying so while doing it — ” going to so and so’s crate” for a time out. (Ours will go on their own when ordered to). Then after 15 min can let her out with the ritual of telling her “easy easy” and petting her before letting her go on her on. This exercise is to be activated EVERY TIME she shows aggression toward her sister in receiving affection. Eventually, ramp up the ‘letting her go’ out of the crate procedure by having her sister in another person’s arms receiving affection standing nearby.
      Eventually (and maybe right away) the “NO” when the aggression occurs should be combined with stroking the dog when she stands down and then presenting her sister to her while stroking both dogs. This is a matter of reassuring the jealous dog that she can share affection. This falls a bit into the ‘resource aggression’ category – but jealousy is very real in dogs. I’ve had to counsel parents with newborn babies to never let their dog be alone with the child. Have had mauled babies because of jealous dogs sneaking into the child’s room.

      1. Thank you so much for your response!!! Your directions are very precise and I look forward to implementing these actions to save my fur family.

    2. This advice is based on personal experience. We currently have 8 Basset Hounds. Up until Nov. 25, 2016 we had 4 sisters who were litter mates. The first time I experienced a “pack” fight I was horrified. It also seemed as though 3 sisters would gang up on one. No matter who the conflict started between they would all eventually turn on the 1; and she is now on the offensive. The sister that passed away seemed to be the aggressor. Don’t get me wrong; we still have some conflicts, after all we do have 8 (3 males and 5 females), but now that they are going to be 6 y/o there just doesn’t seem to be that animosity between them that was initially present. We also use 2 liter soda bottles to get there attention; by smacking it against a service, our hands and yes their heads (it does not hurt). I have hit myself in the head as hard as I can and it does not hurt, it does get their attention. Also my partner sat them all down and had a talk with them. He basically told them that we do not hurt the ones we love and he will kill them before they kill each other. I use to breed Cardigan Welsh Corgis and had 3 adult litter mates; I never experienced this with them; hence my horrification when it happened with my Bassets. I do believe it must be more prone in certain breeds. My true advice is perseverance, discipline, love, and trust and above all don’t take no s__t……. .

      1. This is too cute. My husband thinks I’m mad when I sit my hounds down to have a tete-a tete. It worked with babies. Fact is, while they might not understand what you are saying — they do receive reassurance and the act builds trust to look to you for guidance-leadership. There are pecking orders and the hounds more than we, at times, can sense the ‘prowess’ of other hounds — ie. who is alpha and the gradation of this. The bassets all knew whom the weaker dog was. There is no rationale of how or who started the conflict — but nature will dictate that the pack turn on the weakest link. They are a liability in the wild and is still ingrained instinctively. The plastic liter bottle is very good. I have used same to get attention. I have also used a flimsy fly swatter smack on a table or butts etc. to get their attention, when whistling or hand clapping doesn’t do it.

        Dogs cohabiting together do get into conflicts over a multitude of environmental stimuli, resources and interactions – and behave as sibs – regardless of genetic links. All in the household comprise “The pack” (same as “the family”) dynamics apply – but a bit more intensely based in survival programming. Reasoning, which humans do have the benefit (if utilized) is attributed largely to the “prefrontal cortex” – which, our canine loves have little (no abstract, consequent, or anticipatory thinking). The more rudimentary you can see the world — the more you’ll understand canine think and response.

        Our newest boy rescue – is very very demanding. Initially, we saw his behaviour as threateningly aggressive – very off-putting for the rest of the family. For some unknown reason I’ve never been fearful of him – will tackle him and/or put my hands over his mussel when he is going off on someone (human or dog). Our household often reverberates sounds reminiscent of wolves attacking. But, we have since learned that this is a ‘play’ or a demand for a toy from another. He does target the beta in the group and pretty much leaves the supreme alpha alone — He adores the beta and goes into a profound funk whenever I take the beta with me overnight on a visit. After play attacking (which is just too aggressive for normal settings) he will ‘groom’ the beta and kiss him all over.

        My husband and daughter were somewhat scared of the new boy’s aggressive behaviours toward them (understandable) – but now get him and are no longer concerned and simply ordered him to ‘knock it off’, which he usually does. They now understand that the wolf hound was either ‘over-protective of me (takes this responsibility very seriously), demanding that they play with him or give him something he wanted – or he was warning them in being overly protective/possessive of resources.

        He was abandoned quite young and lived on the lam some while. 8 1/2 months later he is more secure and better. But, I DO NOT recommend that anyone get a wolf mix for a pet. They are NOT pets — but require much accommodation, understanding and knowledgeable technique. I happen to love mine very much but can certainly see how most would not be able to deal with him. BTW — they are trainable (if they love and trust you). For ex. took a bit to get him to understand to not potty or mark (2 other boys to compete with) in the house anywhere (too big of a house and easy for him to sneak off somewhere). He is completely trustworthy now. The 3 boys do have ‘pissing contests’ in their approved potty area – which is amusing to watch. It is natural for dogs to seek to relieve themselves anywhere so long as it is not near where they eat or sleep or where you eat or sleep (a respect thing). They will abide by your wishes to go in a designated area with consistent coaching and praising – just as a matter to ‘please you’. He knows all the commands if he wishes to comply.. But, understanding these guys is so key to training and calmer living. He stills has the bad behaviour of very aggressive ‘demanding’ for what he wants. We are seeing some progress where is his learning to ask for something more ‘nicely’.

        I continue to work with him to be ‘gentle’ but attacking and dragging the beta around is ‘so much fun’. When I take him alone for an overnight visit to my daughter’s, he is so much calmer and obedient – though, he does attempt to engage my daughter as a substitute to the beta in rough play. She modifies it. But, the demanding nature – loud barking and taunting prance go on for a bit till he is unsuccessful in engaging her on his terms. I digress.

        Problem with the beta is that he will instigate the rough play occasionally, which puts the wolf shepherd into absolute heaven. No serious brawls have escalated beyond a flash in time – but on rare occasion I’ll get a yelp from someone who will come in for some quick coddling and then immediately go back to the fray. Is no different than several brothers horse-playing/fighting dynamics – as I experienced first hand in my childhood household.

        I echo the advice above — training and discipline. Dogs understand “no” – time-outs and reward. Their behaviour can be modified. I am probably too lax with my new wolf-boy – but they do not accept the usual dominating dynamics we often resort to in training work breed type dogs. These require this technique more often than many domestic house pet breeds. But, wolves absolutely will not accept tyranny in any form. They seek to please the one they love and trust. So, have to build this. Mine still pee’s in place when my husband commands him to do something – whereas I simply ask or motion.

        We have the sibling syndrome with my beta and new dog — but not viscous. So, other than the ‘sound effects’ that would give most ‘pause’ – they are vigorously horse-playing and the beta can stand down the new boy anytime he wishes. He was beat upon by his alpha liter-mate brother in younger days – by now is the target of our new alpha – who is not near as alpha as our supreme alpha who is so ‘refined and mature’ now. The beta just has to ‘dog up’ and defend himself. I do occasionally make the new boy stand down when it gets too rambunctious indoors, but no serious harm gets inflicted.

        Packs of dogs will always present a challenge of some sort – just as packs of children do. Engaging them frequently in organized play and/or training does much to alleviate their boredom, wear them out and make them more receptive to ‘instruction’. Otherwise, smart work breeds will find ways to amuse themselves. Other breeds could be subject to the same.

        Apart from my former ‘exercises and discipline’ advice for the bassets — engage them more as a pair in structured activities.

  193. Might add, if your dog responds to treats – once she ‘stands down’ on being aggressive – have treats at the ready. Ours don’t respond to treats – just verbal commands and praise. But, if yours do respond to treats – this may expedite the behaviour change process. Praising and stroking while presenting the treat initially in the process will then permit you to advance faster with just the verbal and petting with no treats. As progress is made, however, do give a treat (always with praise) periodically and without a pattern to ‘reinforce’ the operant behaviour training. Praise will eventually be enough.

  194. I wish I had read your article before we decided to get a male/female GSD littermates. They were great siblings but she is now repeatedly attacking him. Not over things. Just him looking at her. Started the day after she was spayed. They are almost 6 months old.

  195. I didn’t know about littermate syndrome and I’ve had two Chiweenie sisters for over a year. The time that I’ve had them, I’ve noticed they’re so afraid of people and other animals, they never leave each other’s side, they’re always fighting when I take them out to the bathroom, and they hardly obey me. When they were younger, I used to keep them in the same cage but now I have them in separate cages although they’re right next to each other. I guess I’ll be leaving them in seperate rooms from now on.
    I went on vacation over the past summer and I took one of the Chiweenie girls with me and left the other with my mom (I was only on vacation for about a week) and the first night she was fine, but then the rest of the time we were there, she was shaking all the time, whining non-stop, barking non-stop, searching everywhere like she was lost, and when I took her out for walks it seemed like whenever we passed people she wanted to pull me in their direction. I didn’t understand why she was doing this at the time, but now I do.
    I have one question though, one of the Chiweenie sisters has been breaking her cage lately and is pulling everything she can find through the wiring of the cage; could that be another symptom of littermate syndrome? If it is, I think I should consider giving one away…..

  196. I have a sister and brother 4month Chiwawas. The male is the runt, mom lives with us and a older male. Jada had 4 pups and almost died after a c section. I had no idea that i was hurting the last 2 siblings keeping them together. Help

  197. We too made the mistake of getting boy littermates…. they were the best of friends until we just had them neutered 3 weeks ago. They now hate each other and can’t be together without getting into a horrible fight. They are Cairn/Boston terrier mix. Both wonderful, well behaved boys…. just not with each other anymore, we are heartbroken. We will be rehoming one of them, but recently found out that their parents had another litter and the owner is keeping a female for us. Would siblings in this case work? Perhaps a male and a female from different litters would work? We certainly don’t want to make the same mistake…. can you advise on whether siblings but from different litters is ok? Thank you so much!

    1. The issue isn’t with siblings per se, but with siblings (littermates) from the same litter due to the two puppies being at the same stage of development. Also, mixing genders is always a good idea. When you talk to the breeder about getting the female, ask them why they would send two puppies from the same litter home with one owner!

  198. Would love to learn what we can do at this point. My wife a veterinarian (has no real knowledge of dog behavior) and me a prior K9 trainer knew this was a ticking time bomb. Well, we have 2 litter mates Chiauauas she raise from birth, bottle feeding every two hours. I met her a year ago so there was no help at that point. Both dogs have kidney issues but one way worse than the other. Long story short one is much more likely to die sooner than the other. They sleep in the same crate and when speperated for even a short period both freak out. Any tips on how to help this even though I’m sure it’s almost a lost hope.


  199. What do you do and how do you treat littermate syndrome, when the dogs r different ages, breeds and genders?

    Our trainer says ours has all the signs, but it’s never heard of and has to be extremely rare. 😢

    We r so lost!

  200. I have two dogs that are littermates and the mom and dad .well the two daie and little man are two years old any how they always got along up until three or four months ago . anyhow they have been in four serious fights. Well we decided to seperate them on two different. Occassions but when we bring them together after two weeks they still growl and act like they hate each other and fights. So we keep them seperated .im asking why do they do this and what can i do . i love my dogs they are my children. But i miss dale real bad cause hes the one that goes with are friend. My heart is so broke over them i want my babies to be with us . and get along . my boyfriend says we have to get rid of them both. If one has to go . i cry almost every day. Over this. .please help me

    1. Hello Connie. Don’t despair.
      Didn’t catch the breed which can make a bit of a difference – as the larger breeds can be a bit more challenging. Their age (2 yrs) signals coming into young adulthood (if smaller breed – often 3 to 4 yrs with larger breeds – so would be mid adolescence). Either is a mile stone. The falling out could represent the differing imprimaturs of the differing genders as they come into greater awareness of being. Keeping them entirely separated (no exposure) is not going to repair their relationship. They need to be in the same environment, but controlled (ie. one outside, the other inside; one or both separately kenneled/crated for a while, on leash for each adult and made to mind – ie. a sit down or lie down while everyone reads or watches TV. They don’t get to be unsupervised or loose together until more detente is displayed. I had to ‘introduce’ my new boy to the others in a control fashion as above. It would have been a full out fight otherwise.

      Crating them in adjacent kennels over night did the trick. They became accustomed to each other and then limited togetherness, both on leash eventually did the trick. Now they play again – though the wolf-shepherd can be a handful and his idea of ‘love and play’ can be over the top (is still immature – only 2 1/2 yrs while the 2 others are 4 1/2 years old). We let the wolf dynamics play out (aggressive play usually ends up with kisses – lickies and nibbles on the face- and in the end they all insist on being on my bed (260 lbs of dog -I lost that battle of keeping them off. Could banish them but can’t help spoiling the fluffs).

      I digress. For your little canine brother and sister impasse, controlled exposure is the key. You may need to make some environmental changes temporarily -(ie. crates in the main room or bedroom if they won’t settle down in their own beds) and them on leash – not always tethered if not needed, but can drag it around inside. Dogs feel a little bit vulnerable with the leash on and more receptive to your ‘directions’. And, it is more than time to engage them separately in training exercises (15 to 20 minutes of teaching simple commands – and the school walk etc.). The more they see you as their undisputed leader and learn that you have behaviour expectations – this will spill over into their sibling behaviour. If you aren’t confident of being the trainer — then I suggest you find a PetCo (much more reasonable in cost) to undertake some initial classes for you and the pups. Won’t take many to begin to understand how to think primitive young canine. Also, canines can be possessive and competitive – just like us. Make sure each pup has a unique toy that is just theirs and when one shows displeasure at you giving or the other seeking attention from you – (possessiveness and competition for you) caution the aggressor followed by a command of a time out (sit or lie down) and after 15 seconds give them a praise/petting/treat so they associate that their ‘standing down’ is what you like.

      By the way – alpha really means “First” and should be thought of in this manner. The “First or number One” sets the tone and course for the pack – is seen as having the primary responsibility of the pack’s welfare. The “First” is looked to for ‘Leadership’ and emanates – very importantly ‘confidence’. This inspires ‘trust’ which makes the alpha dominant through conferred respect – and, contrary to what is commonly misunderstood — alpha does not need to use ‘fear’ to govern and alpha does not mean dominating, domineering, or tyrannical. Wolf packs will ‘unseat’ an alpha who is a tyrant and does not put the pack’s welfare ahead of himself – he then becomes a gamma (lowest ranking position in the pack- look for professional wolf experts’ writings to read more on all of this). One more note on this. In our human-canine families/packs – the alpha often has to be the ‘enforcer’ as well. The enforcer sometimes has to be use his ‘weight’ so-to-speak to make a point of discipline. I’m lucky in that I am the alpha (dogs look to me for direction, are obedient to me) and my husband is the enforcer if some pointed reminders of expectations are needed (just wait till your dad comes home -LoL)

      These adolescent pups of yours are feeling new oats and just need proper discipline, clear lines drawn with expected behaviours – and of course, will take much reinforcement to get the message across (copious praise and rewards would be helpful when they display ‘social’ behaviour – especially toward their sib). Discipline (ie. teaching in what ever way is effective) begins with the mom – and then becomes the job of the ‘enforcer’ for actual wolf pack expected behaviour dynamics. Canines aren’t born with automatic programming, they must be raised like all mammals.

      So, Connie, get those babies back into the same household with the barriers recommended above – and it WILL sort out in time. If it becomes overwhelming – just put them (or order them – ours go on order now) into their crates for a time out. Think of it like the school yard falling outs that happen and then with proper measures – the kiddo’s are all playing again.

      1. I raised two boy poodle puppies, same breeder, two different litters though. So that may be a tad different. But just after being removed from the breeder’s, they latched onto each other right away. They’re 5 years old now and they’ve turned out beautifully. They’re both confident and have no problem being left behind when I take one of them away or being separate for anything. They’re best buds and play and hang out together most of the time now. I don’t worry anymore about making separate times for each. They’re well established and accustomed to alone time.

        They utilized the ex pen when I couldn’t watch them and they were in there together. They slept at night in two separate crates but next to each other. One benefit was that there were no sleepless nights for me…no crying or howling since they slept side by side, but in their own crate. During the day they went on their own, separate walks, their own, separate training times several little 10 minute one on one times with me. Sometimes they went on walks and such together, but plenty of apart time. They each had their own outings to various places we’d drive to, like the pet store or the vet for socialization or a visit to a friend’s or family member’s house. One of them turned out to be a show dog… and there were times where I was away with him for 3 or 4 days at a time and I had my ex stay with the other and the older third dog I haven’t mentioned. He looked after them and I went off with the one show dog. We all played in the back yard together so they weren’t all the time separated. That wouldn’t seem natural to me, as they really loved each other. But they learned how to get along independently of one another without going to the extreme that some people recommend, as in keeping them totally apart for a very long time. That is not necessary. So, from my perspective it does not have to be such a big deal as long as you take the extra time and effort to show them life is fun without the other one around and that they will get to get back together again in a while.

        If you’ve already got a problem with two older pups, do some separation exercises, but keep them short at first and not too much. Don’t cause a lot of stress in your pups. Gradually condition them to tolerating small bits of *very* rewarding times alone. Get some help. Get someone to distract the one that’s left behind while you work with one of them or take a short walk with one. Have that person take the edge of the loneliness just a little bit. Short, frequent practice sessions. I think they can learn to manage or tolerate some alone time even if they’ve gotten very dependent on each other. Practice some obedience with each at separate times, play some confidence building games. (Google) And help them learn some independence.

        On Sun, Aug 19, 2018 at 6:24 AM Jeff Stallings, CPDT-KA wrote:

        > Alex Buick commented: “Hello Connie. Don’t despair. Didn’t catch the breed > which can make a bit of a difference – as the larger breeds can be a bit > more challenging. Their age (2 yrs) signals coming into young adulthood (if > smaller breed – often 3 to 4 yrs with larger bree” >

  201. Connie. In your initial comment — mis-saw the ‘l’ in Dale as an ‘i’ – so thought we were dealing with a boy and girl. But no matter and makes more sense – the bristling. All of the above still applies, regardless of gender. Competition would be more expected between sib boys as they come out of puberty. Follow my recommendations previously noted and you’ll be fine. It may take a little bit more maturing on the boys part to work thru this stage. Have your boyfriend read the above — very important. Getting dogs is no different than raising children –it is a commitment and when they are in the midst of adolescence – we simply cannot give up any more than you can with children. Good news is that the boys will mature thru it much faster than children — but proper training and barrier control is necessary (ie. crates, leases). The dogs will eventually be fine with each other. I’ve taken adult male dogs and eventually established detente – but takes training and commitment and surely your boyfriend did not expect the dogs to come with automatic proper behaviour programming. They have to learn just like us.

    You could handle this yourself if need be, if your boy friend isn’t willing to stay the course. Might have to make some other arrangements for awhile.

  202. We adopted a brother and sister from the rescue league. They were they only ones left from the the litter, climbed on our young son’s lap.We adoped them and then were told we probably shouldn’t have adopted siblings because when one dies ……. That was the only reason and now they are 10 we are terrified of that. perhaps because they are different genders – but they had been the best of the best. We cannot imagine them seperated. Different personalities. Take care of each other in different ways. Love each other. Put up with each other. So if same sex siblings is an issue – our brother and sister were never an issue. We would have died without them. Just scared to deal with the end of life.

    1. I have mom, her son and daughter. Though it is a huge amount of work and patience the two siblings are like any kids.. . Kids lol. Mom kicks their buts every so often and I’ve learned action is the key. I adopted a tactful way to teach them if I pick up the fly swatter and snap the sound on a table they immediately are at attention…. I’ve never hit my babies with one but they seem to believe the table was in great pain. Lol I can not see keeping the 4 from the litter but these two I’ve fallen in love with,therefore threat them with CONSISTENCY and AWARDS system when they correct a wrong and you will be exhausted but proud and in love.
      I would not recommend having siblings by choice but when left with them it is doable….

  203. Hi I unknowingly adopted sisters! They where 3 months old? I went to get 1, but felt guilty, they were so close to each other! However, one is really out going and the other is shy of people, Iv noticed that they don’t like to be separated, they are one! In training again, play at a doggie daycare, Emma, doesn’t like anyone coming at her so I have to warn people, she’s ok after being around them! Iv noticed that her sister bell, doesn’t like her being with other dogs ? But they play when off leash with other dogs fine? I’m working on Emma’s people issues! They both sleep with me also! They will play with other dogs though, it’s weird and I feel Emma gets anxious when bell leaves her?? Know I see but I can’t imagine giving either up now!!

  204. Adopted two Lhasa/Cocker cross brothers when they were 9 months old, they lived in a pet store for 7 months. Have not had one incident of fighting, they spend all of their days together, sleeping, eating, playing and walking side by side daily. Although I feel badly for experiences listed, I am so pleased that I brought them both together home. I cannot imagine them living apart from each other.

  205. Hi – and thanks for your informative article Jeff, it’s answered questions I had about my current litter sisters (Rhodesian Ridgebacks) – and helped me plan for future! For past 20 years I have had RR litter sisters. As current pair are now ‘seniors’ (and have problems you describe) I went looking for info ..

    Can see now that original RR litter sisters (adopted at 8 weeks) ‘organically’ had the upbringing you advise – as I shared (diligent) care with a neighbour. Both were beautifully well adjusted girls.

    I adopted second pair Ridgeback litter sisters (without help) at 3 years old – owners returned them to breeder, who asked me to try with them – as no-one else would consider adopting both, and they couldn’t be parted … They were raised together from 8 weeks, with minimal socialisation, and no separation, and had all the problems you describe, other than aggression to each other.

    It took 2 years of EXHAUSTING (and very lonely) work to train and socialise them so they could be safely off lead without running down any dog smaller than them as ‘prey’, nor threaten to bite any human that gets too close. Encouraging time apart has helped, though they suffer when separated for Vet visits etc. Even though they now almost 11 (and have many human and dog friends) I still have to be constantly alert to potential problems, and have to confine the girls when I have any friends over who aren’t knowledgable about dogs, or when there’s a crowd of visitors. They are lovely dogs (thankfully very bonded to me also – perhaps Ridgeback trait of strong loyalty also helped with this?) and I have learnt a lot in the process of training them, but I would not now get 2 litter mates together again. I hope people reading this will strongly consider their circumstances (and stamina!) if thinking of adopting litter mates simultaneously.

    Thank you again for your excellent article (and advice about socialising pups early.)

  206. Thank you for this article which is giving us much food for thought. We are early in our journey, and our case is “classic” – we figured since we wanted two dogs eventually, why not get all of the puppy madness over at once and the breeder encouraged our decision. While we second-guessed our sanity in getting two pups soon after, we were oblivious of this “littermate syndrome” until our dog training class instructor mentioned it to us. We are now at 14 weeks, and are a bit worried about many of these issues in the time to come, especially with two males. That said, I do feel like we’ve done a few things right from the start. 1) We socialized them with both people and dogs at a very early age. At just under 9 weeks, we took them to a city neighborhood night market which was swarming with people. While we didn’t want to overwhelm or scare them, it turned out to be the best decision we could have made. Of course we carried them separately the whole time, but there was such a line of people of all ages to see our cuddly pups, they learned to love the attention of strangers. 2) Since then, nearly every weekend we’ve taken them to an outdoor concert venue where they have free concerts in a large field (we stay back away from the speakers and major crowds) and there they’ve had the opportunity to meet many wonderful people and pets. One of our males in particular, has become the official greeter and gets so excited anytime someone or some pet comes near and only confused if they ignore him! The other comes in for the playtime after the first has greeted the guest. Both seem equally fond of people and other dogs. 3) We’ve started taking them to doggie obedience immediately, and to counteract their bond, my husband and I take one and stick with that one for the whole class and we keep ourselves several dogs-lengths away. I know that there’s more we need to do with separating (but this is definitely a LOT of work) walks and such but so far, I am feeling optimistic that we may avoid some of the problem behaviors (at least the fears) that others have experienced. I think early socialization is key. Luckily we live in Pittsburgh, a pretty dog friendly city where a lot of outdoor events, dog parks, etc. are within easy reach.

  207. I adopted 8 week old black labs, brother/sister. Started immediately training them not to jump up on people. If together, they only had eyes and ears for each other. If training apart, they cried and looked for each other. No luck training.When they were grown they had eyes FOR each other. Finally rehomed them,as they ran over me, knocking me down. Having hip replacements, that had to stop! The new home was much nicer than ours.K

  208. I have two siblings male and female I rescued at three and a half weeks old. They are American pitbull terriers. Jack and Jill. They have been around other dogs and play well with them can I go to my mother’s and my youngest son who still lives with her has a Staffordshire Pitbull that’s the same age they play very well together. My oldest son has a pitbull that is 3 years old and they love playing with him sometimes he is not is tolerable LOL. They are crate trained overnight they are house trained. They do wonderful together. I have taught them how to sit in to stay. I’m just blessed but I have not had none of the issues that I have read about

  209. I had two large, mixed breed male puppies…Crush and Riggs. When they were young, they played well together and got along just fine. As they grew older the difficulties began; play that was too rough; spats over toys; bullying and out and out fighting. At 101/2 months of age, I sadly had to rehome one of my boys. (This was after I ended up with 7 stiches in my hand and a puncture wound and huge bruise on my arm after breaking up two vicious fights.) My daughter found a loving home for Crush. A co-worker of hers adopted him and he has landed in the lap of love and luxury! The family instantly fell in love with Crush the moment they saw him. This helped to ease my guilty conscious and lessen my unbearable grief because I had no choice but to give him up. I loved Crush so very much and still do. His brother, Riggs is just a big, black teddy bear and we love him to bits! He has become much calmer, less anxious around other dogs and generally happier. He gets along well with our 14 year old boy, Kipper. Had I known about the potential problems of adopting littermates, I would never have done it. It would have saved me, my family and the dogs so much pain and suffering. This article has been eye opening. I saw my dogs’ behaviours over and over again as I continued reading. Both Crush and Riggs are with families that adore them. They are well cared for, much loved and thriving. Thanks for printing this important, informative article.

  210. I’ve four large great Pyrenees German Shepherd male littermates. Ialso have the German Shepherd dam as well as the great Pyrenees sire with them.
    The only problem I have is that whenever 1 brother goes down playing or even when I roll him to check for fleas, the others want to attack him.
    The sire is around he breaks them up. No argument allowed. Dad is alpha. This seems to be the only way to raise littermates. They don’t do this with mom are dad getting belly rubs. Thank you for a great article

  211. Interesting read …I adopted litermates male an female huskies…they have no problem being seperated ….none of the problems suggested in the article exsist between these two. I do have a 15 yr old husky who is the alpha so maybe that has helped.

  212. What about if the dogs mate with the each other and have puppies like mine did on accident. Now I have 5 adorable pups and they all look normal and healthy but I’m not positive. What are health factors I could be facing

  213. My dog had five puppies we gave away two and had someone that was going to take another one ended up not taking her so I ended up with three puppies they are about 5 months old. the other night they were out in the yard playing and to the puppies are bigger than the other one she was the runt of the litter and they started fighting. they tore open spot under her arm and she had several areas with no hair. I tried wetting them down with the hose pulling them off and they just kept going back for more . she really could have been severely hurt luckily there is two other people here at the house with me to help me pull them off. So I have found homes for the other two. You don’t know how much guilt I feel over this I do not recommend raising siblings together especially if one is smaller than the others.

    1. We went through the same thing for 7 years with 4 sisters from the same litter. We just re-homed them all to separate homes last year. it broke our hearts, but it was best for them. Sibling rivalry syndrome is a real thing. Sometimes it goes the other way where they are so attached they go through separation anxiety when apart.

  214. 6 weeks ago we rescued 2 8year old litter mates that were in the shelter. The shelter wouldn’t separate them as they had always been together. They had not been in the best situation in their previous home and were left outside most of the time.
    At first when we got them they curled around each other. With our love and patience they started snugling us and needed to be right on top of us.
    Now, when I leave the house or room. They display intense anxiety and run to the door constantly, until I come back, even though my wife’s in the home with them.
    They smaller one also is now attacking her sister for what appears to be no reason. This is getting worse.
    We love them both and want to work through this to give them a great life.

  215. Hi Jeff, thank you for this article. I have been reading about litter mate syndrome a lot recently. We just got a female wire haired dachshund (she is 9 weeks old) and are thinking of getting her a male companion in 3 months time. I had dachshunds before and know they don’t like being alone hence we are really determined to get two. They wont be from the same litter of course but are only 3 months apart. Do you think a litter mate syndrome is possible if the dogs are from different litters but the gap is only 3 months? Thanks.

    1. I usually prefer there be about a year between dogs’ ages, but these symptoms are less likely to occur even with 3 months difference. Follow the guidelines for separate crates, training, socials, etc. and you’ll reduce the likelihood.

  216. Hello! Hoping you might be able to weigh in. Like many commenters, my husband and I had not heard of littermate syndrome and we adopted female border collies sisters. They are now 1 year old. They have exhibited classic symptoms- the submissive sibling is still not fully house trained, they have both struggled with basic training even though we have been working with a trainer for a full year, and they cannot be walked together. The more dominant female is incredibly aggressive with other dogs when they are together and the more submissive female also gets aggressive when her sister is around. We had resigned ourselves that they just might not be able to be around other dogs but this weekend the more submissive dog attacked my 4 year old niece. She did not break the skin but out of nowhere (not triggered by movement as my niece was standing still) she jumped on her and bit and scratched her face and shoulder. We are devastated. From what I’ve read I’ve been wondering if it was her trying to establish dominance as she is the bottom of the pack (two other dogs were also visiting). We are committed to training them and don’t want to rehome either dog unless it’s absolutely necessary. I’ve read that homes that have one dog of a different gender, breed, and size sees littermates do better. Have you heard of this? We considered adopting an adult, male, large breed (calm) dog to help break up the pack mentality and to allow them to bond with another animal, but don’t want to make it worse.

  217. On August 7th, we got 2 Siberian Huskies, a male & female, from a breeder in Illinois. Nothing was said about Littermate Syndrome. We found out about it today from a trainer at Petco. We were in the process of buying another crate as they were getting to large for the one we bought. Tonight we had some signs of littermate syndrome when we put them to bed. We listened to them howl for almost an hour. Now they are sleeping. As of right now the crates are right next to each other. Will slowly separating the crates help? The puppies are about 5 months old and get spayed and neutered in November.

Jeff Stallings, CPDT-KA
Dog Trainer and Author

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Jeff Stallings, CPDT-KA
Dog Trainer and Author

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