Myths And Truths About Littermate Syndrome

Disclaimer:  This blog post consists of my experiences and opinions as a dog mom.  I am in no way an animal behavioral expert or veterinarian.  You should consult your own veterinarian and/or animal expert before making any decisions regarding the well-being and health of your pets. 

Add the word "syndrome" to any phrase describing your pet’s condition and it immediately sounds super official, potentially harmful and definitely like something you want to avoid at all cost.  If you circulate within the dog mom community long enough you are bound to hear about the dreaded “littermate syndrome” sooner or later.

What is littermate syndrome?  Is it fact or fiction?

Littermate Syndrome, What Is It?

The term littermate syndrome describes the believed underdevelopment and explosively aggressive behavior which can occur when pup siblings, aka littermates, are raised together.  Traditionally, puppies are removed from their siblings and their mothers at around 8 weeks of age in order to join their forever homes.  It is believed that when littermates remain together past this  recommended nursing period, they will become unhealthily bonded together in a manner which is detrimental to their ability to develop their own identities, operate within normal canine social circles and bond with their human parents.  

What Is Littermate Syndrome?

Is Littermate Syndrome A Myth or Fact?

One can find countless stories of pup siblings who seemingly suffer from the common symptoms of littermate syndrome.  These include severe separation anxiety among themselves, extreme bouts of sibling aggression, an inability or lack of desire to imprint on their human parents and difficulties interacting with, and meeting, other dogs or humans.  

It’s interesting that while this term is used freely within the canine community and among certain breeders, there are vey few scientific studies which confirm its actual existence.  It is also of note that while there are many dog behavioralists who swear by its existence, there are also many dog breeders who successfully raise littermates while breeding purebred lineages.  

While the dangers of littermate syndrome have been clearly outlined, how can there be so many examples of siblings who have seemingly successfully navigated puppyhood without incident and graduate into adulthood as well-adjusted individuals?  Is littermate syndrome a thing or not?

While I am not a professional canine behaviorist, neither am i a breeder nor a veterinarian; I am a dog mom of three — two of which are littermates.  So I can describe to you my experience with raising siblings as well as my overall opinion on whether raising two puppies at the same time is a good idea.

I would, though, like to clearly note I did not seek out to adopt twin dogs when I went to the pet shelter.  In fact, after almost two decades of raising dogs I was rather against it.  Not for any fear of littermate syndrome, but instead because what sane dog mom wants to housebreak two puppies at the same time? 

Housebreaking littermates can be exceptionally challenging

My Experience With Littermate Syndrome

My experience with littermate syndrome can be summed up rather succinctly:  I have seen zero evidence of it.  I have observed no extreme interdependency exhibited by the twins.  Nor have I experienced any unexplained or explosive bouts of aggression towards each other, other dogs or humans.

While the twins, Dylan and Delilah, did arrive in my home with some unusual quirks; it's hard to say whether those were due to littermate syndrome, or the incompetence of their original owner, or the normal stresses of temporary shelter life.  That said, the lack of destructive behaviors among the twins did not come easily.

Choosing to raise two puppies at the same time is not for the faint of heart, the disorganized or dog mom novices.  One may think the hard work of raising and training two puppies instead of one would double.  But in truth, it increases exponentially.

Just as human children, and especially twins, need to be given individual love, attention and boundaries, canine siblings require the same.  Dogs are inherently pack animals but they do rely on clearly established boundaries and social hierarchies to peacefully coexist.

When raising littermates, the dog owner must clearly establish all social rules and boundaries.

Normally those rules are naturally clarified by differences in age, experience and even body weight.  It's also very common for younger dogs to defer authority to older members of the household.  However, those natural distinctions are removed when dealing with littermates; as are the consequences which older dogs would normally give the younger siblings when their behavior becomes unacceptable.

This means that it's up to the pet owner to clearly establish, not only the social hierarchy, but also all boundaries and behavioral expectations.  Instead, what often happens is that owners pull back and spend less time with littermates; reasoning that the dogs have each other to play with.  Left to their own devices the puppies' behavior and social skills deteriorate faster than the characters in Lord of the Flies.

Having an older dog in the household can help littermates learn appropriate behavior and proper socialization skills.

Life With Twins

So how does a dog mom clearly establish boundaries with twins?  For one, I have my older dog, Paris, to act as a big sister.  As a secure, positively contributing member of the canine community, Paris helps to correct inappropriate behavior and also builds the twins' confidence when they encounter new experiences.  

In fact, one of the reasons the pet rescue felt homing Dylan and Delilah with me was a fit was that I had an older dog.  Just as older family dogs often help to train new puppies which are introduced into the household, Paris helps the twins learn socially acceptable behaviors.

In addition to the presence of a more mature canine in my home, I am also a super structured dog mom; especially during puppyhood.  As a result, our daily schedule for meals, walks, snacks, obedience training, downtime, playtime and bedtime is super structured and predictable.  Predictability is extremely important when training dogs.

And of equal importance is scheduling individual training and bonding time with each dog.  What does that mean for us?  That means 3x the dog walks, 3x the obedience training and 3x the downtime.  It means each dog gets one on one training and bonding time with me daily.  It also means each dog gets alone time where they are left to play or nap by themselves and decompress.  And it means each dogs sleeps in their own space and in the own bed.

Another important predictable factor is the structure of meal times and training sessions.  Paris is always served her food first.  She is always the first one asked to do a trick and is always the first to receive her treats.  Then between the twins, I have established that Dylan is next in line.  So he is always second in each of these activities; with Delilah being last.  Why?  Because a hierarchy needed to be established for all of the dogs and as the pack leader, I established it.

My experience with littermate syndrome

Final Thoughts

In order to ensure each dog develops their own identity and becomes self-confident, I spend much of my time training them individually to be secure when experiencing the world with just me.  It is very important that the most important individual in the twins' lives be me and not each other.

So to close out this post I'll say this regarding littermate syndrome: I do believe it is a behavioral condition which pup siblings can develop if they do not get the required obedience training and individual socialization which they require.  I also believe that these puppyhood requirements are more easily and naturally met when a household only raises one puppy at a time.

And while I am successfully raising littermates, due to the extensive amount of time, energy and knowledge needed to do so successfully, I would not recommend novices attempt to do so.  In my opinion only those with a high level of experience and the ability to commit to the serious time investment required, should even consider taking on this challenge. 

To follow our little pack's journey and for more dog mom lifestyle tips, follow us over on Instagram.

For more resources regarding littermate syndrome, please see below.
Littermate Syndrome | Dog Mom Magazine
Littermate Syndrome Does It Even Exist | Behavior Matters Academy
Don't Take Two Puppies: Littermate Syndrome In Dogs | The Bark
There's No Scientific Reason To Believe Littermate Syndrome Exists | The IAABC Journal
Littermate Syndrome: Everything You Need To Know | Great Pet Care