Can Cats Have Littermate Syndrome?

What is littermate syndrome?

Littermate syndrome refers to a set of behaviours that can develop when two or more puppies from the same litter are raised together in the same home. These challenges can make both training and bonding more difficult for the owner and can also lead to a range of behavioural issues for the dogs involved.

Common signs of littermate syndrome:

Overbonding between siblings: One of the most prominent concerns of raising littermates together is that the puppies can form an intense bond with each other at the exclusion of human family members. This intense canine-canine bond can create various challenges:

  • The dogs may become highly distressed or anxious when separated, even briefly.
  • They might prefer the company of each other over humans.
  • It can inhibit the bond between each dog and its human family.

Training challenges: Raising two puppies simultaneously can make training more complicated for several reasons:

  • The puppies might distract each other during training sessions, making it harder for each one to learn and focus.
  • Training sessions may need to occur separately, which doubles the owner’s time commitment.
  • Reinforcing desired behaviours and discouraging unwanted ones can be inconsistent, especially if the dogs egg each other on in mischief.

Development of fearful or aggressive behaviours:

  • There can be a significant risk of one puppy becoming dominant and the other becoming excessively submissive or fearful.
  • The puppies may become competitive with each other, leading to frequent fights, especially as they reach adolescence. This aggression can sometimes be severe, with siblings who once played together harmoniously now unable to be in the same room without conflict.

Uneven development and social skills: The personalities and developmental progress of the puppies can vary. One might become more dominant, outgoing, or advanced in certain skills, while the other might lag behind or become overly reliant on its sibling.

Decreased socialisation: While it may seem that having two puppies means instant socialisation, the opposite can be true. They may become so focused on each other that they fail to engage properly with the wider world – other dogs, people, environments, and experiences.

Maisie and Peach

Maisie and Peach

We recently adopted two cattle dog puppies from the same litter, and have experienced some of these behaviours associated with littermate syndrome. Maisie (blue) was adopted first, followed by Peach (red) a month later.

It can be a challenge to separate the puppies, however, that’s more to do with the other one not wanting to be left out and training is difficult unless I separate them, as they just run amok and don’t follow instructions.

Maisie is certainly the alpha of the pair and is very people-oriented and outgoing. Peach, on the other hand, is shy, introverted and actively rejects attention from strangers. As far as bonding with human members of the household, both have formed bonds with us, however, Peach can be a little fearful towards our son.

I would say the hardest aspect of raising littermates is having to deal with two teething puppies at the same time. Their relationship with us is strong, although Maisie has exhibited somewhat of a jealous streak when Peach gets attention, which she doesn’t exhibit towards our older dog.

Do cats get littermate syndrome?

Littermate syndrome is primarily associated with dogs. The social structures, communication methods, and development of cats and dogs differ in significant ways, leading to different behavioural outcomes.

  • Different social structures: While both cats and dogs are social creatures, their evolutionary backgrounds are different. Dogs evolved from wolves, which are pack animals with distinct social hierarchies. Cats, on the other hand, evolved from solitary hunters, and though domestication has made many cats more social, they don’t have the same pack mentality as dogs.
  • Less reliance on social learning: Dogs learn a lot about behaviour from watching and interacting with other dogs. This makes them more prone to the behavioural challenges of littermate syndrome. While cats do learn from one another, their behaviours are less influenced by their peers compared to dogs.
  • Cats often benefit from sibling company: In many cases, kittens raised together can benefit from the companionship of their siblings, especially in homes where the human occupants are often away. The play between kittens can help them develop good motor skills, social understanding, and even boundaries.
  • Independence: Cats are generally more independent than dogs. Even when raised together, kittens tend to develop individual personalities and often spend a good amount of time doing their own thing.
  • Less training and structured socialisation: Dogs require more structured training and socialisation than cats. Most dogs learn sit, come, wait, heel and leave it. With dogs, the presence of a sibling during formative periods of training and socialisation can be a distraction or a crutch. Most cats don’t go through the same rigorous training routines, so there’s less opportunity for a sibling to interfere.
  • Different forms of aggression: While cats can and do exhibit inter-cat aggression, it manifests differently than in dogs. It’s not uncommon for sibling cats to become less tolerant of each other as they reach maturity, but this isn’t directly analogous to “littermate syndrome” in dogs.

That said, not all cats will get along with their siblings indefinitely. As they reach maturity, changes in the relationship might occur. Some cats that got along as kittens may have disputes or territorial issues as adults. It’s essential to monitor relationships and provide resources (like separate feeding areas, litter boxes, and resting spots) to minimise potential conflicts.

Can I adopt two kittens from the same litter?

Yes, in fact, we recommend that busy households consider two cats who can keep each other company when their humans are out of the house.

Pros of adopting littermates

  • Having each other to play with can help kittens to burn off energy and reduce boredom.
  • Playing with a sibling can help a kitten develop social skills and learn boundaries. They learn from each other about what’s acceptable play and what’s too rough.
  • Moving to a new home can be stressful for a young kitten. Having a familiar sibling can provide comfort and make the transition easier.
  • Kittens are curious by nature and having a sibling to explore their new environment with can be reassuring.

Provide separate resources

Even if they’re siblings, it’s important to provide separate resources to prevent competition. This includes multiple food bowls, water dishes, litter boxes, and resting spots. No matter how well cats may get along, having to share resources can potentially lead to disputes.


  • Julia Wilson, 'Cat World' Founder

    Julia Wilson is the founder of Cat-World, and has researched and written over 1,000 articles about cats. She is a cat expert with over 20 years of experience writing about a wide range of cat topics, with a special interest in cat health, welfare and preventative care. Julia lives in Sydney with her family, four cats and two dogs. Full author bio