CVC Highlight: Rethinking the causes of canine aggression

In 1993, when the American College of Veterinary Behaviorists was formed, dominance-related aggression was routinely diagnosed in dogs referred to behavioral specialty practices.1 Then, as today, owners were seeing aggressive behaviors in their dogs, and they wanted to know what they could do about it.

Ellen M. Lindell, VMD, DACVB

Owners and practitioners had observed that aggressive behavior most often occurred when owners attempted to take food or valuable items away from their dogs. Aggression might also be exhibited when a dog was booted out of bed or when it had been harshly reprimanded, particularly after a prior confrontation. Small children were frequently targeted and might be bitten for climbing into a bed or onto a parent's lap when a dog was nearby.

The hypothesis was that these dogs, being pack animals, were attempting to climb to the top of the social ladder. After considering some observations that had been made while studying social hierarchies in chickens and captive wolves, experts concluded that aggressive behavior in pet dogs was related to dominance—hence the term dominance-related aggression.

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But behaviorists have now come to realize that the term dominance-related aggression is not only simplistic but is often inaccurate.2 Dogs that bite their owners usually do not exhibit the calm, confident, take-charge posture of an animal that is dominant in a relationship. These dogs do not strut up, ears and body erect, and stare until the owners step meekly out of the way.

WHAT SIGNALS REALLY SUGGEST

Instead, aggressive dogs often exhibit an assortment of postures that can be difficult to interpret but that suggest a dog in conflict. A dog might have one ear forward and one ear back. Or a dog's ears might point forward assertively while its tail is tightly tucked, indicating fear. Owners routinely report that their dogs tremble after a bite and often slink away or "look sorry."

Furthermore, some aggressive dogs do not exhibit noticeable warning signals at all. Without attempting to communicate intent, they react by biting. But is biting a successful strategy for attaining a respected leadership position in a social group? Impulsive aggressive behavior instead may suggest an underlying pathology such as anxiety.

CONFRONTATIONAL TREATMENT STRATEGIES

When aggression was considered secondary to a dog's motivation to dominate people, it made sense for therapy to focus on helping owners regain control. Unfortunately, underlying fear or anxiety often was not addressed.

More disheartening was the way some trainers and even veterinarians interpreted the dominance theory. Owners were told that they must fight to win, whatever the cost. Confrontational treatment strategies were routinely adopted, with corrections applied until there was evidence of submission. Mechanical devices might be used to increase the intensity of corrections, thereby enabling meek owners to more successfully punish their dogs' aggressive responses.

Of course, whenever any therapy is implemented, some patients will respond. But corrections were often poorly timed, and the intensity of the punishment might be too high or too low. These factors often served to increase the frequency and intensity of aggressive behaviors in dogs. With confrontational techniques, both people and dogs are at risk of being injured.

And when all the fighting was over, the dog's motivation for biting remained unchanged. Aggression began because of confusion, and aggression continued because of confusion. Moreover, the bond between the owner and dog was further damaged.

A BETTER APPROACH

Instead of focusing on offense and defense, a strategy that teaches communication skills may be sufficient for a successful outcome in dogs with fear- or anxiety-related aggression. Owners can learn to communicate their intentions and their expectations to their dogs. For example, a dog might hunch over its rawhide bone as its owner enters the room, probably expecting that the treasure is about to be confiscated. A simple "good boy, relax" can be used to communicate that the bone is of no interest to the owner.

To some degree, dogs can also be taught to communicate in ways that are clear to humans. Consider the dog that has been taught to follow a command. The manner in which the dog responds can reveal quite a bit about its mood. A dog that immediately responds to the command "lie down," that exhibits relaxed eye contact and gentle forward ears, and that does not attempt to spring up or pull away is communicating a willingness to continue the interaction. However, a dog that plops down upon hearing "lie down" but then quickly leaps up or remains down but stares stiffly with its ears back is communicating discomfort. Of course, it may not be safe to continue the interaction with this uneasy dog, particularly if there has been a history of aggressive behavior. Canine postures can be quite subtle, but educating dog owners to accurately identify and understand the implications of their dogs' postural changes is an integral part of a successful treatment plan.

In dogs that exhibit abnormally high levels of fear, using confrontational treatment strategies carries a great risk of increasing fear and aggressive behavior, making it difficult to ensure safety. But if the underlying fear and anxiety can be reduced and if triggers can be predicted and managed, then the outcome can be favorable. Behavior modification may include relaxation exercises combined with desensitization and counter-conditioning to known triggers of aggression. Some triggers may need to be purposely and carefully avoided to help prevent confrontations, particularly during the early treatment phase. Such avoidance can be accomplished by the judicious use of gates, crates, or leashes.

It is generally helpful to increase a dog's vocabulary. By training a dog to respond to many cues there will be increased communication and therefore predictability in the relationship.

Finally but perhaps most important, it is essential to abandon the use of punishment in the treatment of dogs exhibiting aggression toward their owners. Even if owner safety and dog welfare were not considered (which they should be!), there is the simple fact that the delivery of punishment must be precise in both timing and intensity. Incorrectly applied, punishment routinely increases fear and decreases predictability—the very conditions that created the aggression in the first place.

WHAT IF IT REALLY IS DOMINANCE

Of course, some dogs do calmly and confidently guard resources. They may lean forward, even giving a bit of a snarl or growl when told to obey. If aggressive postures yield the desired results, then aggressive behavior is likely to escalate. In these cases, a diagnosis of dominant behavior or dominance-related aggression may apply. But this behavior can be addressed safely, without the use of fear-based tactics or physical force. Owners can be educated to reward desired behaviors and discontinue rewarding unsafe or unwanted behaviors. Dogs can learn that calmly offering appropriate postures, rather than assertive or aggressive postures, earns them all the resources they need. Reward-based training can be used to teach dogs to follow commands with alacrity, eliminating the need for owners to shout instructions or pull their dogs physically.

CONCLUSION

We still have a lot to learn. Our understanding of canine behavior increases daily, with new behavior studies regularly being published worldwide. Regardless of what we learn, there will never be a reason to abandon the humane treatment of our patients or to risk fracturing the human-animal bond in the name of therapy.

Ellen M. Lindell, VMD, DACVB

Veterinary Behavior Consultations, PC

6 Brenner Ridge Road

Pleasant Valley, NY 12569

REFERENCES

1. Bamberger M, Houpt KA. Signalment factors, comorbidity, and trends in behavior diagnoses in dogs: 1,644 cases (1991–2001). J Am Vet Med Assoc 2006;229(10):1591-1601.

2. Luescher AU, Reisner IR. Canine aggression toward familiar people: A new look at an old problem. Vet Clin North Am Small Anim Pract 2008;38(5):1107-1130.