Aggression is the most serious behavior problem and is surprisingly common in pet dogs. It is a myth that only "vicious" dogs bite or that once a dog bites, the only alternative is to put her to sleep. Advances in understanding and treating aggression offer more options than ever before.
UNDERSTANDING AGGRESSION
Virtually all species of animal have a variety of aggressive behaviors in their repertoires, to defend themselves from perceived threat as well as to compete for resources such as food, mates and sleeping locations. Also, as predators, dogs will chase and bite in the context of hunting for food.
Selective breeding, or domestication, has toned down or stylized much of the aggressive behavior in domestic dogs. Behaviors like watchdog barking, herding, pointing, compulsive fighting and retrieving are all modified forms of aggression and predation.
Animals such as dogs, that are physically equipped to inflict great damage, have evolved ways to ritualize most of their aggressive encounters. This way, contests can be decided without the use of fatal or maiming force to either participant.
Dogs have a variety of non-contact threat behaviors - body postures, growls, snarls, snaps and lunges - as well as the ability to inhibit the force of their bites, to serve as ritualization.
In a human domestic environment, we would like as little aggression as possible, even of the most ritualized sort, directed at us. To achieve this standard, it is important to both understand the roots of aggression and to intervene with pro-active prevention programs for all dogs.
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AGGRESSION TO STRANGERS
When a dog is uncomfortable around strangers, or dislikes certain strangers, such as men, kids or uniformed people, it is usually because she has not been fully socialized.
A socialized dog is relaxed about the elements in her environment. To become socialized, a dog must have sufficient exposure and positive experiences, especially when young. Socialization can be specific, too. A dog may be socialized to toddlers, because she grew up with toddlers at home, but not be used to teenagers, or to babies. Aggression comes into the picture when the dog encounters something she is not socialized to. She will be highly motivated to increase the distance between herself and who or whatever is making her uneasy. She can achieve this in two ways: she can flee or she can try to make the other guy flee by behaving aggressively. The underlying motivation is anxiety.
When you think about it, almost all untamed, unsocialized animals are neophobic. For example, if a fox came up to you in the forest, what would you think? That it was a "nice" fox? Fear of novelty is a normal, adaptive trait in animals. Our mistake is believing that dogs, by virtue of domestication alone, are no longer animals. Certain individuals, breeds and lines of dog are genetically more difficult to socialize. It takes greater effort, including formal behavior modification, to make them more comfortable with strangers. Sometimes only minor gains can be made and their environment must be managed more carefully, both to avoid risk to strangers and stress to the dog.
A stranger may be a kind, gentle person, but this is not relevant to an unsocialized dog.
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AGGRESSION TO FAMILY
When dogs threaten or bite family members, the usual suspects are resource guarding and poor tolerance of body handling.
Ritualized defense of food, sleeping locations and other resources is an adaptive trait, selected for in group-living carnivores. This behavior frequently pops up in our pet dogs, in the form of possessiveness of anything from food dish and bones to sofas, tissues and even garbage! Luckily, there are exercises owners can do to make their dogs much more relaxed around resources.
Handleability problems are also common in pet dogs. Many will be naturally reluctant to have their bodies touched or manipulated, in certain places or in certain ways. If they are not taught to accept and enjoy handling, they may threaten or bite in this context. Gradual exercises can desensitize dogs to being patted, hugged, grabbed by their collars and to tolerate having their feet, mouths, tails and bodies handled and restrained.
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BITE THRESHOLDS
A mild resource or handleability issue can combine with a mild or unnoticed socialization problem to produce a "sudden" biting incident. Although seemingly unprovoked, careful detective work often reveals that the dog had unaddressed problems in both areas. When these were combined together, the dog's bite threshold was crossed. This is why veterinarians and groomers are at such high risk. They are strangers who must engage in aversive handling.
All issues a dog has must be identified and worked on in order for treatment to be successful.
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TREATING AGGRESSION
Dogs that are undersocialized can often be gradually improved with a combination of remedial socialization and classical conditioning. Both the speed and likelihood of improvement depend on the dog's genetic make-up, age, the severity and pervasiveness of the problem and the owner's compliance with instructions.
Another important factor is how well developed the dog's bite inhibition is. Young puppies learn "soft mouth" by play-biting other puppies constantly. When one bites another too hard, the hurt puppy will yelp and stop playing. Gradually, with repetition, the puppies learn not to bite too hard so that play can continue. This is called acquired bite inhibition. When humans forbid play-biting, puppies don't get feedback on their jaw strength and are at higher risk to grow up without this important line of defense against aggression.
Dogs with poor bite inhibition are more difficult to treat for any kind of aggression problem because of the dire consequences of any re-offenses along the way. When they bite, they inflict worse damage than soft-mouthed dogs. It is therefore extremely wise to allow soft play-biting from puppies and to target the harder bites with immediate non-violent consequences, such as time-outs, to teach the puppy to bite softly before teaching him to not bite altogether.
Most resource-guarders and hard-to-handle dogs can be improved with desensitization exercises. Prognosis depends on owner compliance, the presence of protracted warning signals - stares, growls, snarls and snaps - and the degree of bite inhibition.
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DOG - DOG AGGRESSION
Some dramatic looking, non-injurious squabbling between dogs is normal - it is the dog equivalent of human arguments. Problems arise when such altercations are non-ritualized (i.e. dogs are being seriously injured) or when the incidence is greatly elevated.
Dogs that have serious difficulties with other dogs often have similar issues as dogs that have problems with people: resource guarding (against dogs), undersocialization (to dogs) and poor bite inhibition. Dogs will also occasionally learn that it is fun to bully other dogs. Treatment efforts may include desensitization and counterconditioning, remedial socialization, prompting and selective reinforcement of more polite on-leash manners and changing the consequences for dogs that bully.
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ON-LEASH AGGRESSION
Dogs are highly social, to the point of compulsion. When most dogs spot another dog on the street, they are highly motivated to approach and investigate. Being on leash restricts their ability to do so. The resulting frustration translates into increased excitement and agitation, which can be alarming to the owner, who may then deliberately restrict access, tense up before encounters or even punish the dog. This starts an association between the sight of dogs and frustration as well as owner tension and possibly punishment. A vicious cycle is then born that often culminates in thwarting-related or "barrier frustration" aggression. This, combined with owner-proximity induced resource guarding, is why so many dogs are more aggressive on leash than off.
Part of the solution is recognizing the inherently abnormal situation of dogs meeting novel dogs wi th out freedom of movement. Owners can mitigate this by allowing dogs to approach and investigate friendly dogs or allowing them to do so after performing a "please may I" command such as "sit." If a dog has a well-advanced case of barrier-related aggression, a combination of changing the association from negative to positive, obedience proofing and remedial socialization will usually produce profound improvement.
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SIBLING RIVALRY
Fights between dogs who live together are very common. Dogs compete for resources such as food, bones, toys, owner attention and sleeping spots and have individual preferences and moods. Many dogs are also sensitive about proximity and body-contact. If the fights are non-injurious (i.e. you are not at the vet's following each fight having one or both dogs sutured), there are a number of options, including non-intervention. Fights are usually context-driven and, once the triggers are uncovered through detective work, some combination of obedience routine to manage the dogs, selective reinforcement of better behavior, changing emotional associations ("good things happen to you when SHE'S around") and time-out penalties for fights will bring relative peace. If the fights are damaging to either participant, efforts must be much stricter, with an airtight management regime usually being necessary.
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DOG PARK FIGHTING
Dogs can be bullies, competitive over resources, socially uncomfortable or defensive and male dogs are at statistically very high risk to tangle with other males. This mix can make for regular excitement at dog parks! The solution, as usual, lies in correct diagnosis and intervention. If dogs play well usually but seem to target certain dogs for bullying, they can be given time-out consequences (much like a "rough play" or even "game misconduct" penalties in hockey) for their bullying behavior. The penalty must be given every time the dog starts bullying if the behavior is to be affected. If dogs are strong resource guarders, this can be ascertained and managed. If dogs are undersocialized, their confidence can be gradually built up with careful planning. And, it is difficult to overstress the importance of neutering male dogs, mainly to prevent their scent triggering other males!
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PREVENTION
Prevention of aggression is much easier than treatment. Socialize your puppy to as large a variety of people and friendly dogs as possible. Make it fun with lots of treats and playing. Practice anti-guarding exercises. Teach puppies to bite softly by using time-out consequences for hard bites before forbidding all play-biting. Handle your puppy all over and make it fun with treats and praise. Find and enroll in a reward-method puppy kindergarten class that covers these exercises and allows free puppy play. Maintain socialization and comfort around resources and handling in adult dogs with regular practice. Maintain your dog's soft mouth by insisting she take treats gently and by carefully monitored and controlled physical games, such as tug. Allow your dog regular opportunities to socialize with other dogs.
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Dog Bite Prevention
- Breed/select dogs for friendliness to all people, rather than friendliness to familiar people only: help end the market for "one man dogs" and dogs who are "wary of strangers"
- Socialize puppies extensively to a wide variety of people, dogs, other animals, sights, sounds and places: the most advantageous (and most sensitive) age is from 3 -12 weeks
- Avoid negative experiences, especially in puppies
- Attend a reputable puppy class
- Handle all body parts extensively - the goal is a puppy who is relaxed and enjoys being touched
- Practice food bowl exercises and object exchanges to teach the puppy to be relaxed about human presence around possessions
- Maintain socialization in adolescent and adult dogs, including regular dog-dog free play
- Know warning signs: discomfort around strangers ("he takes a while to warm up," "oh she's just protective" etc.), possessiveness around food dish or objects or discomfort being handled, and intervene early - get help from a qualified trainer or behaviorist
- Never approach or pat a strange dog: after obtaining owner consent, encourage the dog to approach you - this means if no owner is present, never seek contact and, even if the owner is present and consents, if the dog doesn't approach, don't touch
- Teach kids about dog safety and respect for animals
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SF/SPCA Articles on Aggression
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