Canine Aggression

Early recognition and prevention of canine aggression

It is difficult to find a book or an article about canine aggression that does not begin by stating two givens: Aggression is the most common and usually the most serious behavior problem in dogs. And more dogs are given up to shelters (and subsequently euthanatized) because of aggression rather than for any other reason. Veterinary behavior clinics and individual animal behaviorists throughout the United States report that canine aggression is the most common diagnosis for dogs they are asked to examine and treat.

But as the euthanasia figures indicate, treatment for aggression is not always successful. Some behaviorists go as far as to say that aggression is a chronic problem that can be controlled in the majority of cases but can never be cured. The experts also say that owner compliance with treatment and early recognition of aggressive tendencies are critical to management of the problem. Management in these cases can be translated another and blunter way-critical to the life of the dog.

The painful outcome of uncontrolled aggression

Before examining the roots of canine aggression and how it can be mitigated, it might be well to look at ways in which humans can protect themselves from that aggression, regardless of its source. Changing human behavior in this regard may be easier than changing the canine behavior. For one thing, the circumstances/situations leading to canine aggression are complex. Years of close study of canine aggression have led behaviorists to describe from eight to eleven different but related types of aggression. It is very rare to see a dog with only one type, thus complicating the diagnosis and the treatment. It is essential to understand that why appropriate treatment for one type of aggression may result in a worsening of the problem when a different type is present.

In reading the descriptions of each different type of aggression, however, the same words inevitably appear and can be called the practical end or outcome of aggression. When a dog exhibits any of the types, it will growl and then could bite if not prevented from doing this. Sometimes the dog will bark, sometimes chase a human or another animal, but these are variable responses. Of course, the dog will also exhibit changes in posture, placement of tail and ears, and other vocalizations that are characteristic of aggression. These changes should always be noted as early warning signs (unfortunately, however, signs are often very subtle and can be overlooked). They should always be read as warning that the dog's next potential move is to bite, and the bite is directed to the person or other animal that has provoked the aggressive response. From a human point of view, canine aggression often seems "unprovoked" and without cause. From the dog's point of view, every aggressive response is fully justified by the present circumstances. The only practical way to understand, anticipate, and manage canine aggression is in fact to adapt the dog's view of things.

Before considering methods of controlling canine aggression, it is important to examine some of the more obvious, but frequently ignored, means of preventing its most serious aftermath.

Flesh and bones of the data on who gets bitten

Knowing who is a likely victim of an aggressive dog is a first step in the prevention of bites and one that should be taken long before the confrontation between dog and victim ever materializes. Dog bites have long been recognized as one of the most underreported of all injuries. Estimates of actual bites range from one to three million, of which more than half a million are serious enough to require medical attention. The most frequent victims are children aged 12 years and younger. According to a review of the statistics by Dr. John C. Wright of Mercer University, Macon, Georgia, children five to nine years old makeup 25 to-SO percent of dog-bite victims. Children five days to 10 years of age were also involved in more than 70 percent of fatalities resulting from dog attacks from 1990 to 1993.

The usual behavior of young children in the presence of dogs explains both the frequency of attacks and the predominance of facial lacerations from bites. Children approach many dogs at their eye level and are apparently viewed by the dogs as invading their private space. Children may also threaten a dog by direct eye contact, or by competing with the dog for some resource such as a favorite toy or food, or even by engaging the dog in rough play that is perceived as threatening or at least unwanted. (This last may be especially true for older dogs or dogs in discomfort from some injury or disease.)

According to Dr. Wright, up to 90 percent of bites suffered by children were inflicted by owned dogs and not by an unknown or a stray. Many children are bitten by dogs that have been chained for long periods of time. Male children are bitten more frequently than female (from 1.5 to 2.2 times more likely to be bitten). The reasons for these statistics are not certain, but they may result from a male preference for dogs as companions, a factor that makes males more available for injury. Males may also engage in types of behavior the dog perceives as threatening or challenging.

Dr. Wright also found that individuals who own dogs are more likely to be bitten than those who do not. A possible explanation for such events is that owning a dog can lead an individual into assuming that he or she "knows" dogs, can recognize a "friendly" dog, and knows how to handle dogs in general. The adult victims were bitten more often by their own or other owned dogs than by strays.

The ultimate expression of aggression

Common sense can go a long way in preventing dog bites. For example, no one should ever assume that the behavior of an unknown dog can be fully anticipated all the time. Stray dogs, although more inclined to bolt than bite, should be avoided or approached with extreme caution. All children should be taught a rigorous code of etiquette in relating to any dog, especially the one nearest at hand, the one that is, as the data show, most likely to retaliate for any breach of decorum.

Recognizing aggression

The classifications and descriptions of canine aggression have been developed by behaviorists over the last several decades. A frequently quoted presentation is one developed by Dr. Peter L. Borchelt of New York's Animal Medical Center and Dr. Victoria L. Voith of Kalamazoo, Michigan. The descriptive terms are in most instances self-explanatory.

For example, canine aggression is termed possessive when a dog in possession of items like food or a toy barks, growls, or bites a person or another animal that approaches. Protective aggression, highly prized by humans, is shown by a dog guarding its home or area or owner. Pain and punishment-elicited aggression result in attacks on persons who inadvertently or intentionally cause or increase discomfort. Maternal aggression, which can operate at a considerable distance, results when the mother is protecting her puppies, other young or even toys regarded as her offspring. Intermale and interfemale aggression are also self-explanatory. Redirected aggression is often one of the most perplexing for people to understand. The aggression (either as actual fighting or threats) the dog would like to express toward another dog, animal, or even object is turned on a person (or even object) that interferes with this initial aggression, or when the original target of aggression is out of reach. Individuals attempting to break up a dogfight are often the victims of redirected aggression.

At the risk of oversimplification, it could be said that the definition of each of the above classes of aggression carries the key to prevention of injury. For example, owners should not attempt to handle a dog's foot that has been injured. The result might be a display of pain-elicited aggression. Children should be taught not to snatch at a dog's favorite toy. Even the best trained dog may respond with aggression to defend its own territory or resources.

Many behaviorists believe that early training can so mold a puppy's temperament that it will adjust to having the owner safely do such things as removing a resource (food or toy) at will, which would in other dogs potentially provoke an aggressive act. Some dogs can be taught to adjust to being stared at (direct eye contact is generally avoided by animals because it is perceived as a demand to yield prominence to the other); to being roughly handled and turned over and made to assume a subordinate position. Such exercises are designed to try to prevent the kind of defensiveness that can result in the growl, bark, and bite of the aggressive response. However, if the puppy has a predisposition to dominance aggression, these exercises could make him react aggressively.

Generally speaking, the exercises are meant to gradually accustom the puppy to accept the owner as the one who calls the shots, the dominant part of the duo. In the case of eye contact, the owner is the one who holds the pup's gaze without flinching, letting it know who is in charge.

Given the short attention span of puppies and young dogs, such training requires patience and dedication, but it can result in a well-behaved, docile dog that knows its place in the family unit, a place of happy subordination. For many owners, however, the training has usually been put off until the dog has approached maturity and brought along a contrary notion of its place in the real world.

The special problem of dominance aggression

It is often assumed that the most common form of aggression,, dominance aggression, is also the form with the most subtle manifestations and with the most problematic outcome after treatment. The noted behaviorist at the University of Pennsylvania, Dr. Karen L. Overall, says that many so-called "cured" dogs relapse if the owner does not constantly reinforce the dog's good behavior. Moreover, the owner must always be on guard lest the dog get away from subtle, nonaggressive forms of control. A dog who leans up against you and gives a push, a dog who puts its feet on you, a dog who seems to like pinning you down in your chair with its head on your lap is not being affectionate but rather treating you like a member of the pack that can be pushed, stepped on, and held down. Dr. Overall warns that such signs should be read for what they are. Dominance aggression in an overt form should come as no sudden surprise if this kind of behavior has been observed in the past.

Treating dominance aggression

Obedience training in itself is not a foolproof way to eliminate dominance aggression in a dog. A dog may be perfectly trained in the usual routines ("sit," "stay," and the like) and yet still regard itself as dominant over at least some member of the household (an unusual feature of this behavior is that it often does not extend to the entire range of available humans or other animals but can be restricted to one or only a few others).

According to a report by Dr. Karen L. Smith, who did her veterinary behavior work at Cornell with Dr. Katherine A. Houpt, the behavior modification program is based on slowly reversing the dominance hierarchy within a household so that the dog is the subordinate member. The dog must be made dependent on the owner for all things, beginning with attention and affection. All such contact is withdrawn from the dog at first and the dog is trained, fed, and exercised only when on the lead. The dog is kept off all furniture, and all toys, bones, etc are removed. The dog is given a designated area, usually a crate. The dog must be trained to assume a submissive position of "sit" or "down" before being fed, petted, or led out. Commands such as "down" are given frequently in the course of the day. The dog is fitted with a head halter to give the owner better control of its movements (for example, the Promise Behavior Management System collar). If the dog has threatened or bitten another animal or a family member, the use of a muzzle is recommended when circumstances that could potentially lead to another bite are present.

Because of the very real threat of injury to the owner, the kind of treatment required to change dominance behavior should not be undertaken without expert advice. This precaution is obvious when one considers the number of situations in which the dog's previous aggression must be challenged. The dog must be trained to allow the owner to remove his food, other guarded resources, and even stolen objects.

Attempts are made to allow the owner to safely discipline the dog verbally, disturb him while he is resting, stand over and reach down to him, etc. (In some cases, this is never achieved, and the owner is told not to do any of these things.) A dog with dominant tendencies still active will not permit most if any of these activities without protest.

Uninstructed owners often revert to physical punishment, but it is known that the use of force or physical punishment can be dangerous. Pain, as the experts note, has long been known to provoke aggression. Even threatening gestures (loud shouting, arm movements) can also provoke aggression. As Dr. Borchelt and Dr. Voith emphasize, discipline or attempts to discipline a dominant-aggressive dog are the most likely stimuli to elicit aggression. The owner, rather than a stranger or trainer, is most likely to be the target of the aggression because of the dog's relationship with the owner.

Castration and drug therapy

The experts all say there is no guarantee that any specific combination of behavioral modification is likely to succeed in all cases. Very often males, most commonly diagnosed with dominance aggression, will improve when castrated, although this is not always the case. In fact, most males have been neutered before being brought to a behaviorist for consultation, usually at about six months of age, regardless of the dog's temperament. It is clear that testosterone alone does not cause dominance aggression, although it may facilitate and escalate the aggression.

Dr. Smith notes that in females dominance aggression appears at a younger age (less than six months) than in males and worsens quickly. Affected bitches may have delayed or silent heat cycles. There is also evidence that females from litters that were predominantly male are more likely to show dominance aggression and typical masculine behavior. It is assumed that such females were androgenized in utero.

Various kinds of drug therapy have been employed to try to improve behavior in dogs with dominance aggression. Dr. Smith describes treatment with lithium (the most commonly used drug in bi-polar disorder or manic-depression), but the drug has serious side effects, including vomiting, polydipsia, polyuria, coma, convulsions, and death. A newer drug, fluoxetine (Prozac), has also shown some promise, but only a small number of dogs have been treated.

Controlled studies are needed before use of the drug can be widespread. Fluoxetine increases the availability of serotonin, which has been found to exist in lower concentrations in the spinal fluid of dominant-aggressive dogs than in control nonaffected dogs. Drugs that may work in some dogs do not work at all in others, or may take months to show any results. Progestins are perhaps the most commonly used drugs, but because they have such serious side effects as diabetes mellitus and mammary tumors they are considered drugs of last resort.

Dr. Smith reviews the findings on the role of diet, noting that there is some evidence that a low protein diet may help reduce aggression. There is even a study indicating that a diet of white-fleshed fish and bread rolls made hyperactive, dominant dogs more tranquil and manageable. Other reports contest the beneficial role of a low protein diet, but did find that territorial aggression was significantly reduced on the low protein diet. The relationship between diet and behavior is complex and needs further study.