Littermate Syndrome

As a behaviourist, I encounter a vast range of issues affecting dogs. I aim to always provide solutions for owners so that they can get the very best out of their relationship with their dogs. The vast majority of behavioural problems can be resolved, however, there is one particular problem that I have struggled with as a behaviourist, known as littermate syndrome or littermate dependency.  This occurs in some littermates that are homed together as puppies and very much depends on the individual temperaments and environments of these dogs. 

What is littermate syndrome?

Littermate syndrome occurs occasionally when littermates raised together develop behavioural and psychological imbalances due to their co-dependency on each other rather than their humans. It can result in separation anxiety from each other and difficulty bonding with their human family. In extreme cases it can lead to aggression with each other sometimes to the death, aggression with humans and extreme resource guarding of food, belongings and territory to include the members of their human family.  

What are the signs?

• Extreme excitement, under the age of six months, you may notice that your dog struggles to settle or relax.
• Extreme or chronic separation anxiety with intense whining, howling and barking, which relates to separation from the other littermate, generally under 6 months. This may even cause destruction to property.
• Aggressive behaviour between the littermates can be prompted by overly intense play which often results in fights, as they head towards the adolescent stage. In some cases, these fights can actually result in death or serious injury.
• One of the siblings can present a severe lack of assertiveness or confidence that can manifest as anxiety or fearful behaviour.
  Extreme pulling on the lead when walked with their littermate even with tools used to limit pulling such as a halti. One or both littermates will not let the other walk in front.
• Extreme resource guarding of environment, humans, furniture, territory, toys or food which results in fighting between the dogs.
• There may be signs of extreme levels of possessive or territorial aggression inside or outside of the house with strange dogs or humans, generally from the sibling that is the most anxious or fearful.

Although all dogs and littermates are completely different, there are similarities to be seen in the severity and types of the problems. This relates to the age and environmental influences in which the dogs are raised. Owners often think that after a shaky start, some, if not all of the problems have disappeared, but somewhere between 10 months and 2 years, things can change dramatically with serious consequences.
Is littermate syndrome inevitable? 
Some dogs from the same litter can absolutely live harmoniously together, as I have seen many times. That said, the chances of problems developing are statistically higher with littermates and once they are established, resolution is difficult.

Can there be success?

As I previously mentioned, it is possible for this issue to be resolved and for two littermates to live together, but there are always adjustments to the way they live and humans interact with them that need to be carefully put in place and adhered to achieve the highest likelihood of success. An experienced behaviourist is required for this.
Male and female pairs often get on better than two of the same sex.
If one of the littermates is more subservient than its sibling, this can result in less hierarchical behaviour and therefore a greater success in pairing.
Siblings that are introduced into an environment with dogs that are already there can lessen the chances of altercations between the siblings, particularly if the other dogs are older, calm and balanced.
In some cases, success has been seen in households that keep the littermates separate for the first 10 months. This means eating, sleeping, training and socialising apart from one another then being carefully reintroduced. Some people do find adhering to this measure very difficult however and it needs planning, commitment and discipline in the household among the humans to make it work.

What can owners do with their littermates?

The sad reality is that it is highly likely at some point, one of the littermates will need to be re-homed. There are far too many owners who wait until the situation is dangerous or unfixable. As a behaviourist working with the owners of littermates, a thorough assessment will be made in order to pinpoint a plan of action with the highest opportunity of success, working holistically and in partnership with the immediate and wider family and carers interacting on a daily basis with the dogs.

If you think that your own dogs from the same litter are hitting any of these markers, get in touch to book a one-to-one session in order to get a full assessment of the situation.

Azz Rainey is a qualified dog behaviourist working primarily in Oxfordshire, Swindon, Gloucester, and the surrounding areas.