What is littermate syndrome and how can we manage it?

In the animal world, there is a phenomenon called littermate syndrome. It’s when two animals from the same litter are so close that they refuse to be separated from each other and will even try to get back together if they’re ever separated.

When it comes to humans, we don’t have many things in common with our littermates but we do experience something similar- people who were born at around the same time as us often share experiences that nobody else can understand because of their shared environment during childhood development. That includes twins and triplets.

Introduction to littermate syndrome

Littermate syndrome is a term used to describe the strange phenomenon when one dog in a pair of littermates will not be happy with another dog coming into their home. It’s where two sibling dogs have formed an over-strong bond and those two puppies for a whole pack – two dogs against the world!

But first the basics. It’s important for any new addition to your furry family to be properly introduced so that there are no hard feelings, or worse – fights!

There are many ways you can do this, but it’s way to create success by just walking them side-by-side around the house for 10 minutes and then letting them hang out together while supervised. This way they can get acquainted without feeling threatened. If it turns out that your pup has an issue with sharing, it might be time to reconsider if adding another pet is right for you.

Littermate syndrome is a psychological condition that affects dogs of the same breed. It can lead to increased aggression, severe separation anxiety, and stress in dogs who are separated from their siblings.

Does it have to be twins?

Identical twins have similar risks for littermate syndrome than two litters with only one puppy each – but with one puppy it is rarer. This blog will discuss what causes this phenomenon and how you can help your dog cope if they suffer from it.

Littermate syndrome is a type of behavioral problem that occurs when two or more puppies from the same litter are raised together. Littermates can form an intense, lifelong emotional attachment to each other which causes them to become overly dependent and protective of one another.

This often means that they do not like other dogs in the same room or even the same house, and so pets may have to go on separate walks.

While it is in an issue sometimes with dogs from different litters that bond by being the same age, it is far more common with sibling pups or sibling puppies, and those two puppies do not want second dog (ie an out of pack dog) to be with the human family.

These two dogs then form a unit and those two puppies do not like anyone else – even from the same household.

What are the behaviors?

Twin puppies play a major role in each others lives, which can lead to behavioral problems for one or both of the pups as they grow up. These include:

  • Fear of dogs, people, other animals
  • High separation anxiety or extreme distress
  • Crate or travelling issues
  • Issues when encountering new situations when alone
  • More prone to aggression as compared to non-siblings in the same household together

Some problems with littermate syndrome don’t manifest until both dogs reach maturity, but in breeds not typically known for aggressive behaviors the manifestations of these problems intensify greatly.

In Labradors, aggression and fear are uncommon when only one littermate is present. When two littermates are raised together, we see much higher levels of aggression combined with fear.

The reality of the situation is that littermate syndrome can be managed, but it’s a lot of work.  An owner should know that preventing littermate syndrome doesn’t just double their workload; it makes your efforts three times as difficult. You’ll need to train with each dog individually, and then together.

Littermate syndrome is a developmental disorder that causes dogs to not go through their normal development process and takes a lot of work for the owner or those rehabilitating the dog. It is hard work!

Managing the issue early

This can be a problem when dogs littermate syndrome trips over into adult dogs, who are then unable to bond with multiple dogs or even their pet parents,

As they get older, littermate syndrome in dogs may lead to behavioral issues such as excessive barking, aggression towards humans and other animals, territorialism, and separation anxiety.

Get help!

The good news is that these issues can be resolved through training with a professional dog trainer.

Here’s how you might go about finding the right trainer for your two puppies: 

  • Ask friends who own dogs if they know any trainers in your area;
  • do some research online by looking up “dog trainers near me” on Google
  • try and socialise with other dogs and ask your trainer about his or her experience in this regard
  • have they dealt with two dogs with littermate syndrome before? Or other dogs with this littermate syndrome?
  • Does he train each dog separately or together? What do the pet parents need to do?

Don’t Take Two Puppies: Littermate Syndrome in Dogs

Many dog behaviorists, trainers, breeders and shelters discourage adopting siblings. Puppies’ deep bond impedes their ability to absorb and grasp nuances of human and canine communication.

Not all siblings raised together will exhibit this problem, which is called “littermate syndrome”; it’s a risk, not a foregone conclusion, say experts. But many factors influence behavior, not all siblings will exhibit such behavior.

What is Littermate Syndrome?

The name is littermate syndrome, which occurs when puppies are raised with each other in the same litter. It’s important to note that there’s no guarantee two puppies from same litter will develop behavior problems. Littermate syndrome is a result of poor socialization during a puppy’s crucial first 6 months. It can be prevented with specialized training methods for puppy siblings to socialize with other dogs. At 3-month mark, puppies should be separated from their litters and placed in new homes to avoid littermate syndrome.

Signs of Littermate Syndrome in Dogs

Signs of littermate syndrome include excessive crying, whining and destructive behavior when siblings are separated from one another. Puppies may not be interested in playing with other people or pets in your household.

Training two puppies from the same litter may take longer than expected because puppies are so distracted by one another, experts say. There are apps and classes that can help you learn and train your puppy at your own pace from the comfort of your home.

If you’re considering adopting two puppies at the same time, it’s important to consider the challenges that may come along with this decision, so that you can devote the time and energy to positive-reinforcement training.

Together Forever: What if you already have litter mates?

Each puppy must be separated from each other to learn how to be happy with being alone. The cons of adopting siblings far outweigh the pros. Experts encourage multiple dog households; timing, temperament and age that each enters the home is paramount.

For pet parents, always consider whether to have just one puppy, which will help with behavioral issues. That puppy will also go well with an older dog as they will both have more one on one time.

How to Help Behavior Problems

To prevent littermate syndrome, keep siblings separated. Use separate crates, separate rooms, sign them up for separate obedience classes. Allow time for them to play together to help your dogs get along. If you don’t have time, space, and energy to bond with your pups, consider reaching out to a vet for professional help. Get the help of a certified dog trainer or a certified veterinary behaviorist for a professional help in raising siblings together for a long-term, time-consuming work in front of you for the next few months.


Littermate syndrome is a well-documented phenomenon in the animal kingdom, but it can also be an issue for humans. The best way to manage littermate syndrome is by adding new members carefully and with care; you should always introduce them slowly and gradually over time so that they are not overwhelmed or stressed out.

We put together some tips on how you can make sure your pets feel comfortable around one another without any problems arising as a result of their family ties. Follow these steps closely and maintain patience when introducing new animals to each other – this will help avoid potential issues!

Managing littermate syndrome isn’t always easy, but with these tips you can do it. Littermates are often raised together and form a strong bond that lasts for the rest of their lives. This may result in them fighting over food or toys, so make sure there is plenty to go around!

They also need lots of space which means they should not be housed together full-time unless one is being housebroken while the other is out exploring your yard. If possible, try placing a fence between two cages if this becomes an issue as well.

These pointers will help you care for your littermates successfully even when faced with challenges like managing littermate syndrome in dogs at home.

Littermate Syndrome FAQs

Can littermate syndrome be cured?

Owning more than one dog can have some very big benefits but it is also a risk. There are risks when bringing home two puppies at once, like littermate syndrome. In many cases, timing, temperament and age of the dogs that come into the family matter more than how many furry friends they bring in at once

To avoid littermate syndrome, keep your dogs separated. Separate them for bedtime, give them separate crates and obedience classes, and let them play together to help build their relationship.

If you don’t have the time, space, or energy to spend bonding with your dogs, consider working with a vet or animal behavioral specialist for professional help. They can provide assistance in raising siblings together long term and with behavioral issues.

What are the symptoms of littermate syndrome?

Littermate syndrome is a condition that some dogs experience where they exhibit excessive crying, whining and destructive behavior when separated from their siblings – classic separation anxiety. Puppies may not be interested in playing with other people or pets besides their littermates.

Training and teaching a litter of puppies can be quite difficult. According to experts, the littermates are so distracted by one another that it is often much more difficult than if you were training a single pup. When this occurs, many people will enlist help from an online app or tool in order to train their dog with distractions at home.

If you’re considering adopting two puppies at the same time, it’s important to consider the challenges that may come along with this decision, so that you know what behavior training they will need.

What age does littermate syndrome start?

The name of this condition is littermate syndrome and typically occurs when puppies are raised in the same litter.

A study from 1980 also found that it’s not always true that two puppies born in the same litter will have behavior problems later on but there is a chance.

One of the most common consequences of poor socialization from puppyhood is littermate syndrome, or behavioral problems between siblings. Prevention is best done through specialized training for a puppy’s critical first six months with their littermates and other dogs or cats.

At three months old, it is important to separate puppies from their litters and moved to their forever homes.

What is littermate syndrome?

Animal behaviorists have found that animals in the same litter are closer to one another than those born at different times. Animals may refuse a meal if their sibling is not present, and even try to return to each other when they’re separated.

Humans don’t have a lot in common with littermates but people who are born around the same time as other humans likely share experiences that nobody else can understand because of their shared environment during childhood development. That includes twins and triplets.

Littermate syndrome is a term used to describe the phenomenon that often occurs when two littermates become very bonded to each other. Once another dog enters into their home, any of the original litter mates will fight against it with such ferocity as though there were only room for one dog in the whole world.

Before getting into more complicated territory, it’s important to establish the basics of maintaining harmony among your household pets.

Dogs that grow up with their littermates are much more likely to have issues when it comes to sharing later on in life. To curb this, you should try walking them beside each other for 10 minutes and supervising during this time. If the dogs can’t share without one of them feeling threatened, they might not be ready for a new family member.

Littermate syndrome is a psychological condition that often affects dogs of the same breed, and it typically leads to increased aggression, severe separation anxiety, and stress.