Littermate Syndrome

At Vom Aesir Kennels, we will only sell one puppy to a home at a time due to littermate syndrome. We welcome our puppy families to purchase a second puppy after their new family member is a year old.

Littermate syndrome is a serious behavioral condition. The condition develops when two young dogs end up bonding too tightly with each other. It may sound ideal when dogs are such close friends, but major issues can arise down the road. The problem is that their relationship with each other can stop them from creating proper bonds with humans and hinder their social development. As the name suggests, littermate syndrome generally exists in two puppies from the same litter, however it can also be present when two puppies of a similar age are raised together. Although littermate syndrome doesn’t develop every time two puppies are raised together, it is common enough that we warn against getting two puppies at the same time.

Behavioral Issues Associated with Littermate Syndrome

From a young age, the two puppies have formed a very strong bond, learning and feeding off of each others emotions. This can lead to behavioral issues in one or both of the dogs as they develop, these behaviors often include:

Fear of people and other dogs

Extreme separation anxiety

Crate Issues

Issues when encountering new situations when alone

Leash Reactivity

Higher incidence of fighting as compared to non-siblings being raised together

These issues aren’t often experienced right away, but as both dogs reach mental maturity, they tend to intensify greatly. Littermate syndrome often causes aggression in breeds that are not prone to aggressive behaviors. For example, we rarely see aggression in Labradors, but when two Labrador littermates are raised together we see much higher levels of aggression and or fear.

Littermate syndrome can be managed, but it is a lot of work.  An owner should know that preventing littermate syndrome doesn’t just double their workload, but rather triples it. They’ll have to train with each dog individually, and then together. Remember that littermate syndrome is not a dog simply acting out. Littermate syndrome causes dogs to not go through their normal developmental process and takes a huge amount of work to overcome once it is present. At that point you aren’t simply asking a dog not to be bad, you are trying to socialize them long after their “socialization window” has closed. It is hard work!

Avoiding Littermate Syndrome is best!

The easiest way to prevent littermate syndrome is to only take one puppy at a time.  It is always tempting to take two because they are just so darn cute together.  But no matter how cute they are the safer route will always be to just take one.  If you want a second dog, I would suggest waiting 10-12 months and then getting another puppy.  This way the first dog will have already been socialized properly.