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Jeff Stallings

Jeff Stallings, CPDT-KA and owner of Better Nature Dog Training, works and blogs in the San Francisco Bay Area.

Good Dog: Behavior & Training
Don’t Take Two Littermates
Littermate syndrome has potential downsides.

The email described a familiar scenario: “We were planning to adopt one puppy, but the breeder said that raising two sisters would be easier. After we brought the girls home at nine weeks, their behavior became increasingly out of control. My husband and I could not get their attention for more than a second or two—it was as if we weren’t even in the same room. And then they started displaying alarming fearfulness of people and other dogs.” I made an appointment for a home visit so I could meet the family and the puppies.

Many dog behaviorists, trainers, breeders and shelters discourage adopting siblings. Anecdotal evidence suggests that behavioral issues may arise during key development periods because the two puppies’ deep bond impedes their individual ability to absorb and grasp the nuances of human and canine communication. Since fear is the canine’s default reaction to odd or unfamiliar stimuli, this muddled understanding of the world around them can lead to impaired coping mechanisms later on.

Of course, many factors influence behavior, and not all siblings raised together will exhibit this problem, which is called “littermate syndrome”; it’s a risk, not a foregone conclusion.

Early Indicators
Signs include fearfulness of unfamiliar people, dogs and other novel stimuli (neophobia); intense anxiety when separated, even briefly; and difficulty learning basic obedience skills. In some cases, the two dogs will fight incessantly. Over lunch, veterinarian and dog behaviorist Dr. Ian Dunbar and I discussed raising sibling dogs. “It’s a disaster waiting to happen for the littermates because they don’t get socialized to other dogs or people, let alone to their owners,” he said. Many owners assume that the dogs’ interactions with one another are adequate, “but when the puppies are five or six months old and meet an unfamiliar dog in a novel setting, they absolutely freak out.”

Dunbar points out that raising littermates necessitates training two puppies, which is particularly challenging when they’re essentially wearing blinders to all but each other. “It’s more than twice the work; it’s exponential. The two combine to produce levels of energy that we can barely measure. Tension develops in training and compliance as they squeeze the owner out of the relationship. They’re always living with an enormous distraction: each other.”

The Tie That Binds
Cohabitating siblings may become so emotionally dependent on each other that even short separations provoke extreme distress. Behavior specialist and author Nicole Wilde recalls a case in which two nine-year-old sibling Huskies attended her group class. “They were so bonded to each other that I literally could not take one and walk a few feet away to practice loose-leash skills because the other would scream.”

Wilde believes the problems are rooted in hyper-attachment, which leads to hindered social development and communication issues. “People assume that having two same-age pups who play together and interact constantly covers their dog-dog socialization needs, but they in fact don’t learn how other [dogs] play and have no idea about social skills with other puppies, adolescents or adult dogs. Perhaps one puppy is a bit of a bully, which his littermate puts up with, but his rude behavior might not be tolerated by a new dog in a new setting.”

During my appointment with the family, we determined that the best course was to rehome one of the 12-week-old siblings. Dunbar agrees that it’s often best to separate littermates, especially if symptoms appear early, so that each has a chance to develop normally as an individual. This is obviously a burdensome decision for the overwhelmed owner to make, a sort of canine Sophie’s Choice, so he recommends that potential new owners meet both puppies and determine which to take home.

Together Forever
Those committed to raising a pair should ensure that the puppies spend significant portions of every day apart so each learns how to be alone—a key lesson in any well-thought-out puppy program. This means feeding, walking and training separately, with individual crates in different parts of the home. Even trips to puppy socials and the vet should be separate so they learn to incorporate these episodes into their respective psyches without being overly dependent on their littermate. This separate-but-equal arrangement is timeconsuming, exhausting and seems to defeat the original intent of acquiring siblings. Wilde notes that planned separations must begin immediately. “I’ve been called into homes where four-month-old siblings have been sleeping in the same crate for eight weeks and not purposefully separated by the owners, who had the best intentions but were unaware of littermate issues. Even getting the puppies to sleep in separate crates right next to each other is traumatic for them.”

Dunbar, too, is adamant that one of the key lessons a puppy must master is how to be content with being alone, which is all but impossible with two siblings. “Once we’ve done that, yes, he can live with other dogs and have free run of the house. But if you don’t teach puppies early on how to be alone, and especially with siblings who have always been together, it will be catastrophic when one dies.” Dunbar encourages multiple dog households— “I always like having three dogs”—but the timing, temperament and age that each enters the home is paramount.

Most people have never heard of littermate syndrome, finding out about it while researching their dogs’ problematic behaviors. Increasingly, however, trainers and behavior professionals recognize that the cons of adopting siblings far outweigh the pros. “The only advantage I can think of is a short-term gain of the puppies being less lonely in the first month of life,” says Dunbar. “Everything else is a loss.”

Exceptions and Hope
While there are indeed struggles in raising siblings—including ongoing aggression and fighting often seen between same-gendered littermates— there are also well-adjusted cohabitating pairs. A common thread seems to be that littermates are more likely to thrive when introduced into a household with an older dog, who perhaps acts as an arbiter and stabilizing influence.

Myriad factors affect dog behavior, including genetics, early life experiences and owner engagement. As University of California, Davis, veterinary behaviorist Dr. Melissa Bain points out, “Two fearful littermates very well may be genetically predisposed to fear.” Bain is less inclined to apply the term syndrome to the set of symptoms. “It makes you think all littermates have problems, which is not the case.” She also emphasizes that the level of owner involvement is key, saying, “The symptoms escalate when the owners treat them as one dog with eight legs.” When conflict ensues between the pair, Bain believes it’s due to the dogs being similar in size, age and gender. “This uniformity makes it difficult for the siblings to delineate a hierarchy,” she said.

After one of the siblings had been rehomed, I received an email from the owner describing how the remaining puppy began to thrive under a remedial socialization program. “Dora has blossomed in the last three months into a delightful household companion, and she continues to improve. She now approaches people out of curiosity. We know she would still be fearful had we not separated the two before it got any worse. Dora has become more confident with all kinds of dogs, and successfully completed a group obedience class.”

Increased Awareness
Recognition of the risks of dual adoption appears to be spreading, with many breeders and shelters declining to place siblings together. Shelley Smith, adoption center manager at Pets Unlimited in San Francisco, said her shelter stopped placing siblings together after a particularly disturbing case. “A Dachshund mix named Thelma was returned to the shelter because her sibling repeatedly attacked her; she had multiple injuries by the time the heartbroken family returned her to us. Thankfully, we were able to rehome Thelma, but it’s almost certain the fighting and anxiety could have been avoided had the two littermates not been placed together. We now separate siblings and inform adopters about the rationale for our policy.”

While siblings blessed with extraordinary genes and socialization-forward owners may avoid littermate syndrome, the consensus among canine professionals is that it’s not worth the risk. Most would encourage new owners to adopt a single puppy who suits their lifestyle and to focus on the training and socialization that strengthens the interspecies bond unique to humans and dogs. Once your puppy is a dog, by all means, get a second, since the two will be at completely different stages, and the older one may very well emerge as a great life teacher to the younger.

Good Dog: Studies & Research
Get Your Puppy Off to a Good Start

There is no disputing the fact that having rich and varied social experiences in the first three months of life improves a puppy’s odds of a growing into balanced, confident dog. Also not in question is the reality that canine under-socialization can result in behavior problems, fear and aggression, all primary reasons for relinquishment and euthanasia in pet dogs.

The window in which the most effective socialization takes place is only open between weeks 3 and 12 of the puppy’s life; then, it slams shut. Given that the last combination vaccine (against distemper, hepatitis, parvovirus, parainfluenza and coronavirus) is usually administered when a puppy is 16 weeks old, it’s also the genesis of a dilemma.

Some veterinarians, shelters and breeders advise new owners to wait until after a puppy has had her final set of vaccinations to allow her to interact with others. Unfortunately, by that time, the socialization period has ended, precluding the pup’s best shot at acquiring lifelong dog-on-dog social skills.

So, I was particularly interested in a study conducted by the UC Davis School of Veterinary Medicine, which looked at the risks to partially vaccinated puppies of contracting parvo at indoor puppy socialization sessions (socials). The results were reassuring.

Risk vs. Reward

It seems that puppies who have had only their first set of shots are at no greater risk of being infected with parvovirus than those not attending socials. During the study, it was reported that none of the 15 puppies who contracted parvovirus had attended puppy socials, and that none of the puppies who attended socials contracted parvovirus.

This dovetails perfectly with the standard of care recommended by the American Veterinary Society of Animal Behavior (AVSAB), which unequivocally encourages owners to begin socialization classes for puppies as early as seven to eight weeks of age, and seven days after the first set of vaccines. The American Veterinary Medical Association, the ASCPA, and other dog health and behavior experts concur.

As the ASVAB statement reads, “The primary and most important time for puppy socialization is the first three months of life. During this time puppies should be exposed to as many new people, animals, stimuli and environments as can be achieved safely and without causing over-stimulation manifested as excessive fear, withdrawal or avoidance behavior.”

It is important to note that structured puppy socials run by a variety of training and daycare facilities and other pet-related businesses take place indoors on non-porous surfaces, and “accidents” are cleaned up immediately with an antimicrobial solution. Porous surfaces, such as dirt, sand and, in particular, those found at dog parks, must be avoided until full vaccination.

Also, puppy socials do not guarantee that a dog won’t develop fear or aggression later in life; genetics, in-utero experiences, early nutrition and the first weeks with the mother and siblings also play key roles.

Developmental Factors

Why is the window of opportunity so small? At the risk of stating the obvious, puppies develop much faster than their human counterparts. For example, puppies walk beautifully at three weeks, but it takes babies about a year to reach that milestone. This acceleration affects canine cognitive function, which develops rapidly during the short socialization period; it’s during this time that a puppy’s framework for future social functioning evolves. A strong foundation built from a rich set of early experiences gives the puppy more context in which to evaluate and react to future stimuli in the environment, including people and other dogs.

As mentioned, the true socialization period of puppies—the time during which they readily incorporate new experiences into the developing worldviews that directly affect lifelong behavior—lasts from weeks 3 to 12. That’s it. Since most puppies remain with their mother and littermates for seven weeks (a whole other topic), this means that new owners have just four weeks to make sure their puppy has ample opportunities to learn that there are many sorts of people and types of dogs in this world.

Weeks 8 through 12 are called the “second socialization period” (the first having been spent with the mother and siblings). During those 28 days, a puppy’s brain is like a sponge, supple and ready to absorb and incorporate new experiences. This is without question the most profoundly important period in a dog’s life. Her brain is wired to absorb new experiences far more rapidly than during any subsequent period, and she learns not only to accept being around people and other dogs, but also, to enjoy and seek out these experiences.

While not a perfect analogy, a puppy’s capacity to learn social skills is similar to a young child’s capacity to learn languages. Studies have shown that children younger than seven easily pick up new languages because their brains are capable of readily incorporating the sounds, words, grammar and structure of multiple languages.

Like the puppy socialization period that ends at 12 weeks, this window closes for children around seven, after which language acquisition becomes far more difficult. A six-year-old child who spends a year in a Mandarin immersion class will come out fluent in the language. If I were to attend the same class, I would likely still be struggling with the basics.

The analogy continues. My Mandarin would improve over time as I became more familiar and comfortable with the language, but I would never be as fluent as my young counterpart. Likewise, dogs without the advantage of a rich socialization period can learn to thrive in social situations, but it takes a great deal more time and effort and has a lower chance of success.

Country Dog, City Dog

It goes without saying that your puppy needs to be socialized to the environment in which she will be living. If your puppy is not destined for an urban life but rather, say, for the life of a farm dog, socialization to lots of people and dogs is not as important. If your pup’s life will be devoted to managing livestock, this second socialization period would be the ideal time to hang out with sheep, goats, cows and horses.

But 80 percent of Americans live in urban areas, and since more of us have dogs in our homes than ever before, it behooves us to structure our puppy’s socialization period to take this into account. In San Francisco, we have a beach where sometimes hundreds of dogs roam around off-leash at any given time. Our sheepherding dog probably doesn’t need to learn how to cope with that, but if you want to eventually spend quality time with your dog in this lovely locale, you’d best start her education early (yes, during those four crucial weeks).

In addition to socials, a widely accepted goal is for a puppy to meet 100 people during these same four weeks: babies, children, elderly folks, men and women of all races, sizes and shapes, dressed in all sorts of clothing and carrying all sorts of implements—umbrellas, canes, plastic bags. One caveat is that puppy socials and people-meet-and-greets must be positive experiences, not too overwhelming and not too scary.

As your pup’s guardian, you need to shield her from overtly frightening situations (being pursued by an unruly, much larger puppy, for instance), but you must also allow her to venture forth into the rollicking puppy mayhem at her own pace. Sometimes, a timid puppy will hang back for the first few events, and then become a social butterfly. Take, for example, my dog Otis.

As a young puppy, she was shy and unsure of herself. She had been fostered in a rural area of eastern California, so the sights and sounds of the city were initially overwhelming. At her first puppy social, she hung out under my chair and observed the other puppies playing; I did not coddle or overprotect her, nor did I force her to engage with them. By her second social, she was venturing forth, playing for a few minutes, then retreating to her safe place under my chair. By her third social, she was actively seeking out playmates and practicing adult communication behaviors, which is the ultimate goal of these events.

Since Otis was by nature somewhat fearful, I have no doubt that had she not had the chance to come out of her shell among other puppies and to learn and practice social skills, she would be a fearful dog today, possibly aggressively so. Instead, she has superb communication skills and is particularly adept at enticing other dogs to play and chase her. She remains cautious around novel stimuli (a strange stack of wood on our street or a kite hitting the beach nearby), but she is most definitely not fearful. Puppy socials made all the difference.

A word of caution here: Had I taken Otis only to that first puppy social (the one during which she hung out under my chair, overwhelmed and frightened), it almost certainly would have backfired. She would have learned that being around other dogs was an unpleasant experience to be avoided. She might have become aggressive in order to keep them away, like the multitude of dogs who have learned that snarling, snapping, lunging and barking keeps other dogs from approaching. Instead, because Otis had numerous opportunities to learn to how to play at her own pace, she became a world-class communicator.

I mention this primarily because I recently took a call from the owner of a six-month-old puppy whose veterinarian had advised avoiding all contact with other dogs until the pup was fully vaccinated. In this particular puppy’s case, that meant no contact until 17 weeks.

Five weeks past the end of the second socialization period, the pup finally attended one social, and it did not go well. The puppy was terrified and the owner decided not to go back. Now, this young dog’s single point of reference is that new dogs are scary. She trembles in the presence of other dogs, unsure of how to act, or react. A desensitization/counterconditioning program will take months or years, and will never be as effective as if that puppy had been taken to numerous socials while her brain was configured to learn and cope.

Knowledge Is Power

I find it interesting (but not surprising) that in the UC Davis study encouraging early socialization, puppies taken to socials did not contract parvo, but some who were not taken to socials did. New owners who are conscientious enough to learn about the advantages of early and safe socialization are also knowledgeable enough to avoid taking under-vaccinated pups to dog parks, where the risk of contracting the virus is high.

Conversely, people unaware of puppy socials are more likely to take puppies to places they should not be until they’re fully vaccinated, which includes dog parks, beaches and other settings with porous surfaces likely to harbor parvovirus-infected feces.

Puppy socials are just one part of a well-thought-out socialization plan, but they form the plan’s cornerstone and have the additional advantage of being viable before all vaccinations have been given.

In part because the safety and benefits of early socialization are well documented, most urban and suburban areas of the country now have access to indoor puppy socials that require just the first set of shots. This bodes well for the heath and well being of future generations of our best friends.

I hope this sheds some light not only on the advantages of socialization but also, on how such a program can begin early enough to make a real difference in the life of your dog. Now, get out there and mingle!