Ever heard of littermate syndrome? Though not a scientifically recognised medical or behavioural disorder, many trainers, shelters, and vets say it exists. Basically, it’s a set of behaviours that sometimes occur when two puppies from the same litter bond exclusively to each other in a way that interferes with normal development.
Though two barking BFFs wanting to do everything together sounds adorable, it can actually lead to antisocial behaviour towards other dogs and humans and other behavioural problems. So, how to raise two puppies successfully?
In this article
What is Littermate Syndrome?
Littermate syndrome is found in dog siblings that are from the same litter and have been together since birth.
When they’re kept together for an extended period of time, usually beyond 8 to 10 weeks, they may become hyper attached to each other.
This extremely strong bond allows them to have a close relationship with each other, but not so much with other people or animals.
This can be detrimental to their social skills as they’re not able to properly bond with other animals, even other puppies and dogs.
It also affects their ability to develop a connection with the human family they’re adopted into.
Puppies from the same litter who grow up together may develop littermate syndrome. However, it’s not limited to just this scenario. It may also affect puppies from different litters that have been adopted together as well as puppies who perhaps live together in a shelter or a pet store and are constantly in each other’s company.
Interestingly, littermate syndrome doesn’t seem to afflict kittens. In fact, many veterinarians recommend adopting kittens in pairs.
Is it real?
There’s no scientific evidence that littermate syndrome exists, but plenty of anecdotal evidence to support that it does. Some reputable dog shelters and ethical dog breeders won’t allow you to adopt littermates for this reason.
Luckily, it doesn’t affect all dogs that are adopted in a pair. There are chances your dogs will grow up together but won’t develop this syndrome. Another good thing is that there are many teaching and training techniques to prevent these issues from developing.
What are the behaviours of littermate syndrome?
Littermate Syndrome can be difficult to spot if you don’t know what you’re looking for. Keep an eye out for the following signs:
Fear of the unfamiliar
Notice your puppies’ behavior. Are they curious about the wilderness when you take them outside? Are they going up to new people you invite over and sniffing them? Do they growl or bark when you bring new and unfamiliar objects in front of them? If your puppies are consistently avoiding interaction with new people and animals, this should raise a red flag.
Expressing anxiety
Your puppies may experience something known as anxiety separation. This is anxiety they may feel when they’re not around their pup partner and they may show this through excessive whining, barking, growling or panting.
Eating irregularities
Dogs who are experiencing this syndrome may feel anxious eating without their pup partner. Even if they’re hungry, they may only sniff the food and then walk away. Puppies experiencing littermate syndrome will, in most cases, want to eat together.
Playing in pairs
Are your puppies engaging with the external world while they play, but only when they’re in a pair? They may play with your friend’s dog or the new toy you just bought them. However, if you remove one puppy from the situation, the second will stop playing, too.
Difficulty (or ease) in training
As mentioned above, it becomes difficult to train puppies who are facing littermate syndrome. They’ll constantly be distracted by their sibling and will find it hard to pay attention to what you’re trying to teach them.
However, as this Youtuber shows, the syndrome can sometimes make it easier to train them because one pup will follow exactly what the other pup does. It’s important to note that this syndrome may exhibit in different ways in different dogs – and sometimes it may be a positive thing in some areas but a negative thing in other aspects.
Aggression
Puppies who are raised together may be more aggressive towards other dogs and people. Breeds who aren’t known for aggression, such as Labradors, may exhibit more aggressive behaviour if they have this syndrome.
Counter-intuitively, puppies who face littermate syndrome may start showing aggression toward each other and fight constantly. This can become a huge problem particularly among-sex siblings, and fighting can become severe and highly dangerous.
Leash sensitivity
This syndrome may also cause your puppies to be extremely reactive or resistant to being walked on a leash. They may rise up, pull, lunge, jump or snarl when put on a leash, and yet be completely okay to be walked off-leash.
Check out our tips on how to walk a puppy on a lead to find out how to deal with this.
FAQ
So, how to raise two puppies successfully? The obvious solution is to try and avoid homing puppies from the same litter together. You may also want to avoid getting another young puppy soon after bringing one into your family, as it can occur in non-siblings too.
Start as early as possible in ensuring your puppies spend time apart and socialise with other dogs and humans – particularly when they’re around 8 – 16 weeks. They need interact with other dogs and humans as individuals rather than as a pair. This helps them to develop their own social skills.
It may seem like it defeats the point of getting two puppies together, but once you help them overcome their hyper attachment to each other, they can happily live as dog BFFs rather than co-dependent and asocial pups.
Essentially, you’ll want to act as though you have two puppies living in different homes who see each other for play dates. This means feeding, walking, playing with, and doing crate training and behavioural training with each puppy separately. Puppy training school should be separate too. Or at the very least, with two pet parents as handlers working at opposite ends of the class.
You can raise two puppies successfully if you step in early and put in the work to break their hyper attachment and help them realise themselves as separate entities.
It can be good in some situations, but it is not automatically better for puppies just because they’re siblings.
Dogs are not like humans in that sense. In the wild or in free-living dog groups, siblings usually separate naturally as they mature. They don’t typically stay together for life the way human siblings do. So puppies don’t have a built-in emotional need to live with their littermates.
Insure two pups, for less
To raise two puppies successfully means ensuring you have the financial means to cover them in the case of an accident or emergency. PD Insurance is an award-winning brand* that offers a choice of three dog insurance plans. Plus, you can get 1 month free insurance when you sign up. Why not get a quote now?
*PD Insurance is the winner of the 2023 and 2026 MoneyHub Editor’s Choice Favourite Pet Insurer Award, 2024 Reader’s Digest Silver Pet Insurance Award, and 2022 Canstar Most Satisfied Customers Award for Pet Insurance.