By Jeff Stallings, CPDT-KA
Littermate syndrome is a condition in which hyper-bonded sibling dogs have difficulty relating to humans and other dogs. In my most recent case, an owner’s email could serve as a go-to primer for this syndrome: At 12 weeks old, the two puppies were terrified of people and other dogs and frightened of everything outside of their home: Airplanes flying overhead, leaves blowing in the wind, passing cars, and all novel stimuli. It was almost impossible to get the attention of the two puppies even for an instant as they were so focused on each other. They then began fighting frequently.
It is important to note that there are exceptions and that not all sibling pairs will have symptoms, but the risk seems to be fairly high. Anecdotal evidence suggests that littermate syndrome manifests 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 can include:
- Not bonding with humans nor socializing with other dogs
- Not learning to read human signals
- Not learning to trust people
- Playing only with each other to the exclusion of other dogs
- Not learning basic skills, such as potty training and bite inhibition
- Severe distress when separated from each other even for a few minutes
- Fighting with each other, sometimes brutally, as they reach adolescence (at about 8 – 10 months)
The puppies come to rely on each other, which can weaken the confidence of both of them—often to the extent that they become withdrawn from everything other than themselves. One of the dogs may appear bold and the other timid but in reality the bold one is also withdrawn and timid when his littermate is not present to provide support.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 14 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.
In some cases, 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 muddles their learning how the world works. This causes fearful responses to even mundane 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/retreat to 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 or third since the 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.
Note from January 17, 2014: I have expanded this discussion into an article for print publication in which I interview veterinarian behaviorists Dr. Ian Dunbar and Dr. Melissa Bain, as well as renown dog behavior specialist Nicole Wilde. I will update this post once the article is published.