Aggression is the most common behavior problem presented to veterinary behaviorists followed anxiety related disorders (separation
anxiety, phobias). Traditionally, dominance aggression is most often diagnosed, especially when evaluating owner directed
aggression. As a result of the label "dominance" being applied in these cases, owners were often directed to establish themselves
as higher ranking over the dog through the use of a variety of physical means (punishment, alpha rolls, leash hangs, pinch
and shock collars, etc.). Escalation of aggressive responses often followed this approach. By examining the situations in
which the aggression occurs, body posture exhibited by the dog and evaluating the early history of the behaviors it becomes
evident that not all aggression is related to a question of dominance hierarchy. In many, if not most, of these cases a definite
fear component seems to be the driving force behind the aggressive displays. This presentation is meant to clarify terms,
differentiate possible diagnoses of aggression and offer thoughts on treatment of fear associated aggression.
Aggression is a normal canine behavior when displayed in the proper context. As a tool, aggression is utilized by dogs for
a variety of purposes such as acquisition of food, defense of resource (food, territory, mating access), establishment of
pack hierarchy, and self defense when threatened. In addition, submissive displays (averting stares, exposure of the underbelly,
urination and retreat) are often utilized when a dog is presented with an overwhelming threat. If these signals are not recognized,
a subordinate individual may be forced to rely on aggression (growling, barking, snarling or biting) as a last resort.
When examining these behaviors in the context of human-canine interactions, several factors must be considered. Do dogs and
humans communicate in the same manner? While both are social species, methods of exchanging information differ. Often submissive
signals are missed by observers not familiar with canine body language. As a result, dogs may be put in a position to use
aggression when more subtle signals of submission are missed. Over time, learning can occur such that some dogs will totally
abandon these submissive cues and instead more quickly elect to utilize these more offensive strategies to alleviate perceived
Secondly, when punishment is used by humans as a means of exerting dominance, fearful dogs may be forced to respond aggressively
while more confident animals may see the use of punishment as an incentive to engage in a so-called "arms race". This involves
raising the bar by showing higher and higher degrees of aggression in response to ever increasing levels of punishment. In
addition, punishment is often applied in the inconsistently creating an increased anxiety in the fearful animal. Not knowing
whether to expect reward or punishment, conflicting emotions result lowering the threshold of reactivity and increasing the
chance the dog will resort to the use of aggression.
It also appears that fear can be highly inherited so that fearful, anxious or timid parents can produce a higher number of
similarly behaved puppies in a litter. Combine this genetic component with the previously described communication breakdown
and the true meaning of nature and nurture can be seen. In addition, failure to positively socialize during the sensitive
period (up to 14 weeks of age) results in the genetic prophecy of fearful behavior being fulfilled.