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Littermate Syndrome in Dogs: Signs, Causes & Management

Written by: Nicole Cosgrove

Last Updated on June 24, 2024 by Dogster Team

doberman puppies sitting

Littermate Syndrome in Dogs: Signs, Causes & Management


Dr. Paola Cuevas Photo


Dr. Paola Cuevas

Veterinarian, MVZ

The information is current and up-to-date in accordance with the latest veterinarian research.

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Littermate syndrome is a serious behavioral condition that occurs when two or more siblings from the same litter are raised together and form such a close bond that it prevents the proper socialization of those dogs. They are unable to form bonds with humans or other animals, and while it can be treated and overcome, doing so takes a lot of work and persistence. Owners need to overcome the littermates’ reliance on one another while also socializing dogs that are typically past the normal socialization window.

Read on for more information on this behavioral condition, including the signs and what can be done to help combat it.


What Is Littermate Syndrome?

Adopting or keeping two or more puppies from the same litter can seem like a good idea. They have company and they already know one another, so there are no potentially difficult introductions. However, it doesn’t always work out positively.

Littermate syndrome is a behavioral condition that occurs when two siblings from the same litter become too reliant on one another. Their dependence on each other is so strong that they do not form bonds with their humans and will not positively interact with people or with other animals.

Initially, it can seem cute that two puppies are so close, but over time, and especially as the dogs get a little older, it can lead to serious behavioral challenges for owners and the dogs themselves.

Akita puppies eating food_New Africa_Shutterstock
Image Credit: New Africa, Shutterstock

What Is the Cause of Littermate Syndrome?

There are no known physical causes of the condition.

Dogs should be socialized from a young age, which means introducing them to people and other animals so they can form new bonds and will be able to deal with new and potentially challenging situations. If a dog has littermate syndrome, they fail to get this socialization and may struggle with related behavioral conditions.

Two or more developing puppies without the guidance of a mother will often engage in aggressive play and feed on each other’s energy. This exacerbates any aggression-related problems against a third party.

If you have adopted one dog, it can be difficult to identify behavioral problems without knowing that dog’s history.

Where Are the Signs of Littermate Syndrome?

Littermate syndrome is typified by anxiety and signs of fearfulness. These are most commonly seen when a dog is introduced to a new situation or when they meet new people or other animals for the first time. It will especially be a problem if they’re separated from their sibling. Common signs include:

  • Separation Anxiety: Sufferers will usually become anxious when separated from their littermate, even for a very short period of time. They can show extreme anxiety when left alone and may not eat, drink, or play with toys.
  • Poor Social Skills: Your dog may show signs of anxiety or, in some cases, aggression when meeting new people or being introduced to other dogs or animals.
  • Basic Training Issues: It can be very difficult to offer basic training to dogs with littermate syndrome. They will look to their littermate for guidance and may not respond to commands and training provided by others.
grey and black neapolitan mastiff puppies
Image Credit: Fomin Serhii, Shutterstock

What Are the Potential Dangers of Littermate Syndrome?

Littermate syndrome can lead to heightened anxiety in dogs. This may mean they become depressed and withdraw from their family. It can also lead to other behavioral problems and may even lead to aggressive behavior in sufferers. The longer the problem is allowed to continue, the harder it will be to combat it.

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How to Manage Littermate Syndrome

Managing littermate syndrome means separating the dogs, but this itself can lead to anxiety for the sufferers, so it needs to be done gradually and carefully. Try the following steps, and if in any doubt, consult a professional animal behaviorist.

  • Offer them time alone. Start gradually, but separate the two dogs for some time every day. Ensure that the two do not share a crate and that they have separate bowls and are fed apart from one another. You can start by putting the bowls a few feet apart and gradually increase the distance between the bowls before eventually feeding in different rooms and even at different times.
  • Train them separately but within the eyesight of one another. Separate the dogs and give them basic training, but make sure the dogs can see one another. You can gradually start to move the dogs out of eyesight, initially for a short period and then for longer periods as they get used to being apart.
  • Socialize them together. Take both dogs on walks and let them meet new people and other dogs. This will help them socialize without the anxiety that comes from being apart.
  • Walk them separately. Set off on a walk together, but have different handlers take different dogs and try walking the dogs in different directions. Watch how they react so you can determine what needs to be done.
puppies coton de tulear
Image By: JacLou DL, Pixabay

Frequently Asked Questions (FAQs)

Can puppies from different litters get littermate syndrome?

Although littermate syndrome is most commonly witnessed in puppies from the same litter, and that are siblings, this isn’t always the case. Two unrelated puppies that are of the same or similar age and that form a very close bond when they are a couple of months old can develop the condition despite not being from the same litter.

How far apart should puppies be to avoid littermate syndrome?

Ideally, puppies should be aged 6 months apart to avoid developing the condition. Alternatively, if you want dogs of the same age, get them 6 months apart and ensure that they are both properly and separately socialized to avoid the problem developing.

How long does it take for littermate syndrome to develop?

Littermate syndrome can start to develop from just a few weeks of age. Generally, it becomes a problem when puppies are still together after 3 months of age. This is when the dogs should be learning and socializing, and it is when the close bond can start to become a problem.

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Littermate syndrome is a serious behavioral problem that can develop when young dogs are brought up together and form too close of a bond. They do not get appropriate guidance or socialization and will depend on one another for emotional and behavioral support. Once developed, it takes a lot of work and time to correct the issue, but it can usually be corrected. Avoidance is better than trying to find a remedy, however. It is advised that if you want two similarly aged puppies, you get them at least 6 months apart and ensure that both are properly trained and socialized individually.

Featured Image Credit: Pavel Shlykov, Shutterstock

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