09/07/2025
This is real thing I’ve seen with clients’ dogs.
Have you heard of LITTERMATE SYNDROME? If not, keep reading!
We see the comments often. People asking us to adopt out bonded siblings together. We understand the intention behind it. It feels right, even loving, to want dogs who grew up together to stay together forever.
But in reality, keeping sibling puppies together can do far more harm than good.
There is a behavioral phenomenon called littermate syndrome that can happen when two puppies, especially from the same litter or close in age, are raised together in the same home. Despite the heartwarming idea of lifelong companionship, littermate syndrome often leads to serious emotional and behavioral issues for both dogs.
So what is littermate syndrome?
Littermate syndrome refers to a pattern of developmental and behavioral problems that can occur when two puppies are raised in the same home. This can include:
🐾 Extreme attachment to each other and difficulty functioning when separated
🐾 Lack of individual development, which leads to poor socialization with humans and other dogs
🐾 Increased fearfulness and anxiety, especially in new situations
🐾 Difficulty in training, as the dogs focus more on each other than their handler
🐾 Aggression or conflict as they mature and develop different personalities
These issues can begin as early as 8 to 10 weeks of age or may not appear until adolescence. The effects can be long-lasting and very difficult, if not impossible, to reverse.
What does this mean for adoption?
Veterinarians, trainers, and behaviorists strongly advise against adopting sibling puppies, or even two unrelated puppies close in age, at the same time. Many reputable rescues and shelters, including ours, follow this guidance and do not adopt littermates out together. This is not a rule based on convenience. It is based on real experience and our desire to set each dog up for long-term success.
Puppies are kept together in foster when young, but as they grow, allowing them both to flourish on their own is what is best for everyone! Our goal is not to separate loving siblings. It is to prevent them from becoming overly dependent on each other and missing out on healthy development.
But what about kittens?
This is an important distinction. Kittens are very different from puppies. In fact, kittens thrive when adopted in pairs. They learn social skills from each other, burn off energy through play, and are far less likely to develop behavioral problems when they have a feline companion. For kittens, being adopted together is often the healthier, more compassionate option.
What is best for the dogs?
The best path forward is for each puppy to be adopted into a loving, committed home where they can:
🐾 Form a strong bond with their human family
🐾 Build confidence and independence
🐾 Be properly socialized with a variety of people, animals, and environments
🐾 Receive individual attention and training
Dogs are incredibly adaptable. Within days or weeks of settling into their new homes, they form new bonds and begin to thrive. In many cases, puppies that were separated from their littermates go on to live happier, more emotionally balanced lives than those who stayed together.
We know it’s hard.
We love these animals deeply. We want what is best for them, not just what feels right in the moment. And in this case, what is best is helping each puppy grow into a confident, well-adjusted dog on their own.
Thank you for trusting us to make decisions based on the dogs’ long-term well-being. That is always our priority.
