Dog Trainer Philadelphia PA

Littermate Syndrome

Years ago I use to offer free evaluations for a private rescue. They adopted out a lot of dogs weekly. And they adopted out a lot of siblings when they had a litter that was up for adoption. Over the course of 6 months I had about 8 clients that had puppies with littermate syndrome. I quickly discontinued my affiliation after I warned the owner of the rescue of the potential consequences of adopting out littermates. The owner kept adopting them out and that’s when I cut ties.

Many people assume raising two puppies at once will be easier because they will occupy each other’s time but this is rarely true. It’s double the work across the board. It’s a way better idea to not buy or adopt littermates. It’s also a good idea to run from any breeder or rescue that tries to send two puppies home with you.


Littermate syndrome is a pair of littermates raised in the same home that their bond is so deep that it interrupts development in maturation stages which then impacts their ability negatively to develop communication skills with other dogs and their human owners. Training basic obedience commands can be way more challenging vs. if they were separated at 8 weeks. Essentially, they can bond so much with each other that you’re importance is minimal in their eyes.

Because they might not mature properly they can develop separation anxiety, fear of strange things in their environment. They also can be fearful of strange people and dogs. Even worse they can start having severe aggression towards each other which starts out a fight here and there but then turns into them gunning for each other whenever the opportunity arises.

If two puppy pairs develop littermate syndrome there is always one that could live and one that can not live without the other. It’s pretty much an unbalanced, very unhealthy relationship. You have a more confident one and one who is on the insecure side.

This is a condition that is not seen in every pair of littermates, but it’s seen enough to make the risk not worth taking. I’ve seen more cases of littermate syndrome with same sex littermates raised in the same home than opposite sex littermates.

Moral of the story is get one puppy at a time. However, what if you’re reading this and you already have littermates, what should you do?

  • Raise them seperately
    • They should have their own crates and they should be in different rooms.
    • They should have separate training sessions and they should also have separate bonding sessions with their human family. The more time away from each other, the better it will be for the more insecure puppy. It will help him or her develop more confidence.
    • Lots of people like to take their young dogs to places like a pet store for socializing. Take them separately. Essentially, we want them to see the world without each other while they’re maturing.
    • Play sessions should be done separately as well. If you’re out throwing the ball or frisbee, the more assertive one can intimidate the more insecure one into not trying to play. Which then could lead to the insecure one not developing the play skills he or she would’ve developed if you took them out separately for a game of fetch or frisbee.

I personally have bred a couple litters of Malinois and held a couple littermates back to see which ones would be better for competition. I’ve never had littermate syndrome with any of the dogs I bred. But, I raised them away from each other which is very time consuming. It’s so much work that most people ultimately are not willing to put in. You’re better off not doing it. Hope this helps. If you need any help don’t hesitate to call or fill out our contact us form.