Littermate Syndrome: Why raising sibling puppies is misguided
By Jeff Stallings
I have long been aware of risks associated with adopting two puppies from the same litter and recently observed the resultant alarming behavior firsthand. I had encountered “littermate syndrome” before, oddly enough in two puppies who weren’t actually siblings; more on this later. Thankfully, in this most recent case I was able to intervene in time to separate the puppies to allow normal development and socialization to resume—at least for one of the pups.
Littermate syndrome is known by dog trainers and reputable breeders to be a real problem. I stress reputable here because in my most recent case the breeder encouragedthe owner to adopt two female siblings. The new owner contacted me via an email which could read as the go-to primer for this syndrome: At 12 weeks old, the two puppies were terrified of all humans and frightened of everything outside of their home: Airplanes flying overhead, leaves blowing in the wind, cars driving by, and so on. It was almost impossible to get the attention of the puppies even for an instant as they were so focused on each other.
Behavioral issues arise in such instances because during a crucial early development period—when puppies should be bonding with humans, learning the nuances of canine and human communication, and discovering the world—the two puppies instead bond tightly with each other to the exclusion of humans. The symptoms are different in each case, but usually these co-homed puppies will:
▪ Not bond with humans nor socialize with other dogs
▪ Not learn to read human signals
▪ Not learn to trust people
▪ Play only with each other to the exclusion of other dogs
▪ Not learn basic skills, such as potty training and bite inhibition
▪ Be more likely to develop severe distress when separated from each other even for a few minutes
▪ Start fighting with each other, sometimes brutally, as they reach adolescence (at about 8 – 10 months)
The puppies come to rely on each other, which weakens both of them—often to the extent that they become withdrawn from everything other than themselves. One of the dogs will appear bold and the other timid but in reality the bold one is also withdrawn and timid when his littermate is not present to provide support. Unfortunately this is a false boldness as he has been emboldened by the other sibling’s weakness.
Siblings living together often bark at other dogs and may attack to chase other dogs away. This is fear-based; they become so engrossed with each other that other dogs are seen as a threat to their mutual alliance. The siblings become super attuned to anything that may be invading their territory. This unfortunate pair may come to fear all other dogs and unknown people, plus any situation where they are separated from each other.
Seven to eight week-old puppies are ready to leave their mother and littermates to develop normally as individuals. I work with my clients to implement an intensive socialization program to expose puppies to a large variety of people (gold standard: 100 people before 12 weeks of age), children, places, animals, noises, bicycles, cars and so forth. Weeks 8 through 18 are the most crucial, and during this period I encourage my clients to take their puppies to as many puppy socials as feasible. Learning that there are other dogs in the world is an important part of normal social development, and play between puppies is how they learn and practice many adult behaviors and communication skills, including the “calming signals” that dogs use to diffuse otherwise fraught situations.
When siblings are homed together, this socialization process is stopped in its tracks. The puppies are unable to develop the confidence that comes with slowly learning about our manmade world. Their intense bond with each other precludes bonding with humans and makes learning how the world works nearly impossible. This causes fearful responses to the most mundane of experiences, including meeting new people or seeing other dogs on the street, or even watching a paper bag blow in the wind. Sure, we’ve all laughed at a puppy who gets startled by the blowing leaf, but he will quickly learn that blowing leaves are normal and in fact fun to chase. Littermate syndrome puppies are unable to process such occurrences to file them under “normal and fun”, and will instead grow suspect of anything or anyone new.
I mentioned earlier that I had witnessed this syndrome before: A family simultaneously adopted two Shiba Inu puppies that were exactly same age, but from different litters. By the time they contacted me, the 8-month old puppies were holy terrors around the house and next to impossible to communicate with, much less train. To make matters worse, they had no intention of neutering these dogs but instead planned to breed them—with each other. I tried to convince them to neuter both dogs immediately and to re-home one of them and to begin an intensive training and remedial socialization program with the other. They refused each of these recommendations, so I was forced to drop them as clients. (The more unruly of the two was weeks from coming into heat the first time; my reminding them that there a reason for the term “bitch in heat” fell on deaf ears.)
Thankfully my more recent case has ended better. During our first appointment, I took each of the two females puppies out individually and spent time working on treat/retreatto gain trust. Both puppies were initially terrified of everything we encountered on a short walk, but within 30 minutes the puppy would take treats from my hand and respond to cues to sit. With the first puppy, I was able to then enter the home and continue treat/retreat; this is the puppy they ended up keeping—she is now thriving. The other puppy had developed a deeper, unhealthy bond to the first and is having a more difficult time in her new home.
My recommendation is to adopt a single puppy, and to then focus your energy and resources towards teaching that individual all she needs to know to get on with all people and all dogs, in all situations all the time. This is a daunting prospect with just one puppy, let alone two! That said, if someone were to insist on adopting siblings, I would recommend that the puppies:
▪ Be crated separately, in opposing parts of the house
▪ Be fed separately
▪ Be walked and played with separately
▪ Be trained separately
▪ Be taken to different puppy socials
▪ Be taken to the vet at different times
You can see that this would be a nearly impossible task. So take your time picking out the puppy that suits your home and your life, spend the next year showing him or her the world, keeping in mind that all your hard work will pay off with many years of peaceful coexistence.
And once your puppy is a dog, by all means, get a second one since the two animals will be at completely different stages of life. At this point, the older one very well may become a great teacher of love and life to the little one.