Canine aggression toward people: Prevention and resolution (Proceedings)

Aggression is the most common problem behavior of dogs, comprising about 70% of canine cases presented to behavior clinics. This presentation deals with the more common types of aggression towards human family and non-family members.

These topics are discussed extensively in Hart, Hart and Bain, Canine and Feline Behavior Therapy, 2nd edition, 2006, Blackwell Press.

Dominance-related Aggression and Conflict-related Aggression

Dominance-related aggression (also called aggressive dominance or dominance aggression) is characteristically directed toward people the dog considers part of its pack. It is usually a function of the owner's inability to control his/her dog, or the dog's unwillingness to accept the owner's authority in certain situations. With early advice from veterinarians and puppy training classes, the problem could often be avoided. This type of aggressive behavior is usually normal from the dog's standpoint and occurs predominantly in males. Conflict-related aggression refers to where the posture reveals conflicting emotions.

The presenting complaint is usually that the dog growls or snaps at the owner in certain fairly predictable situations. Attacks or threats toward owners are often preceded by discipline attempts, disturbing dogs while resting, petting the dog, reaching for the dog, grooming it, getting the dog off the bed or furniture, taking away objects the dog has picked up, taking food away, putting the dog outdoors. The dog with a dominant personality also will show body postures suggestive of dominance (ears directed forward, elevated tail and staring at family members). Among the breeds most likely to be aggressive towards family members are most of the terriers, chows, and rottweilers.

As for treatment, one can expect castration of males to reduce dominance-related aggression about 30% of the time. The primary behavioral approach usually consists of general, non-confrontational authority-building for the family and addressing the dog's specific "trigger" issues. Simple obedience commands and calm, relaxed body language are used as a rewardable alternative to aggressive behavior, using a type of affection control.

Using affection control, the object is to make it clear to the dog that the owners control things of value. The dog has to obey a command (sit, down, etc.) in order to get what it wants. For 24 hours or so, the dog is ignored (treated like a "ghost") as much as possible. The next day, the dog is periodically called and asked to perform a simple command. Affection, attention and food are briefly given to the dog when it obeys, then the owners "turn off" and ignore the dog again. This continues periodically throughout the next two weeks, at roughly 30-60 minute intervals during the times the owner would normally be interacting with the dog. Non-obedience or aggressive behavior is not rewarded and the owners walk away.

Once the owners feel more comfortable and confident in working with the dog, they can begin to work near the "trigger" situations which evoke aggression. One should set up a "gradient" moving toward situations which evoke aggression. Clients should avoid evoking the aggressive behavior.

Competitive Aggression toward Babies (sibling rivalry, canine style)

This problem may be presented after a couple has a new baby or a veterinarian may be consulted prior to arrival of the baby. As for typical history, the dog has been well-mannered with people until the new child moves in on the dog's share of attention. The dog may growl or in other ways act unfriendly towards the baby. This problem may get continuously worse as the dog is punished or separated from the family when the child is around. For treatment guidelines, affection control is recommended. Withdraw of affection occurs when the baby is not around, and owners give lots of affection and food treats when the baby is around the dog. This is usually the opposite of what has been done before. Getting the dog habituated to rough handling is a good idea before the baby reaches the grabbing and crawling stages. Finally, it is always a good idea to train the child to be gentle and rewarding towards the dog; do not count on this. If the dog has any chance to injure the child, use adequate restraint on the dog while using behavior modification.

Fear-related Aggression

This type of problem is most frequently seen between dogs and people with whom a dog is not familiar. In the typical history, fear is often directed towards specific individuals or categories of people such as children or strange men. The dog will escape, if possible, before biting. Aggression is used to fend off fear-inducing people, and is self-reinforcing. Over time, the dog's fearful body language may become less fearful and more confident and outgoing. Paying close attention to the owner's description of the dog's body language, and when the problem began, helps to clarify the presence of fear as a causative factor.

As for treatment guidelines, this involves gradual or systematic desensitization to fear-evoking stimuli using exposure to the fear-evoking stimulus at a distance and gradually allowing closer exposure. Care must be taken to avoid evoking the aggressive response, and to reward only calm, relaxed behavior during training. Direct or interactive punishment is contraindicated. Use of a basket muzzle and/or a halter-type head collar can enable the owners to work with the behavior and will provide safety for the people.

Territorial Aggression

The dog will usually be presented for showing signs of aggressive behavior towards people coming into or near its territory. The territory may include the home, car or office. The typical history suggests a manifestation of normal territorial aggression towards strangers with major breed differences. Breeds most territorially aggressive are: Dobermans, Akitas, Miniature Schnauzers, Rotteilers, German Shepherds, Chows, and Terrier breeds.

As for treatment guidelines, desensitization is employed, using appropriate restraint (head halter, basket muzzles) to have the dog repeatedly experience initially friends and then strangers beyond critical distance from boundaries where dog shows relaxed, calm behavior that the owner can reinforce. One should stage repeated sessions that are combined with food treats given by clients. As the desensitization progresses, have the dog encounter strangers closer and closer to its territory. The idea is that the dog comes to associate people visiting with positive reactions stemming from food reward. The initial reinforcing is done with food given by the client when the dog is controlled. Eventually, as the dog is habituated to strangers up close, the stranger can give the commands and rewards.

Idiopathic Vicious Attacks on People

This is a type of abnormal aggressive behavior sometimes also referred to as the "Rage Syndrome." The typical history is characterized by unpredictable and unprovoked vicious attacks, often directed towards people the dog knows well. These attacks may occur sporadically. There is some evidence of genetic predisposition. A "glazed look" is often mentioned. The attacks may have some underlying subclinical brain pathology. In Springer Spaniels this is sometimes called "Springer Rage." Some cases of what appear to be idiopathic aggression are actually dominance-related aggression.

As for treatment guidelines, it is almost impossible to evaluate treatment without risking more attacks. Anticonvulsant drugs have been used on rare occasions with some success. Euthanasia would appear to be more justifiable with this than any other type of aggressive behavior, due to the severity of the attacks and difficulty in controlling the environment to avoid them.