Fear Aggression: COMMON and DANGEROUS

Seeking some fun after school one day, your teenage son chases the Cocker Spaniel into the dining room. Cornered, the dog lowers his ears, head, and tail, snarls, and finally bites your son on the hand as your son tries to tease the dog by grabbing him.

The dog’s reaction is “fear aggression”, which is not an unusual canine behavioral problem. Fortunately, this is usually quite treatable, aIthough it may take a few weeks of focus by the whole family.

The punishment didn't fit the crime

Fear aggression may be caused by overly severe punishment or punitive training techniques such as striking the dog. For instance, an inexperienced dog owner, frustrated at being unable to stop his dog from barking at a visitor, may go from a severe “No” admonishment to hitting the dog. For the dog, the learning process disappears in a whirl of fear, to be replaced by the need to defend himself from painful attack.

Perhaps the teenager above had, at other times, hit the dog with his hand, newspapers, or a leash. Soon, the Cocker Spaniel associated the teenager with abuse, which triggered fear whenever the youngster approached. The dog’s growls and lowered head and ears are a warning; but when cornered, afraid, and unable to escape, biting is his last defense.

“The only things that will set off the dog are things that scare the dog,” explains Katherine A. Houpt, VMD, PhD, director of the Animal Behavior Clinic at Cornell University’s College of Veterinary Medicine.

Another common factor can trigger fear aggression: genetics. For example, some dogs who haven’t been abused will react to a frightening stimulus such as a large, unfamiliar man.

Research indicates that German Shepherd Dogs, Cocker Spaniels, and Miniature Poodles tend to develop fear aggression more than other breeds. “And females may be just a bit more fearful because they tend to be a bit more subordinate,” Dr. Houpt explains.


Fear aggression is a natural behavior for a dog based on self-preservation. For instance, a dog reacts this way when threatened by another dog.

However, it becomes a family problem when the training or punishment becomes extreme, such as striking or shouting. The dog’s anxiety forces him to bite back. In training or managing your dog, remember that food treats, praise, and petting are positive rewards for appropriate behavior, and are the best ways to develop the best behaviors.

Don’t hit

“Hitting is something that we do not advocate,” Dr. Houpt says. “It’s harder to build up a dog’s confidence than to push it down with abuse.” When snarls and snaps keep the feared person away, this is seen by the dog as effective, and causes this behavior to occur more and more often.

Dr. Houpt points out that canine aggression of any kind -- such as barking at strangers at the door or snarling at houseguests -- should not be encouraged. “You have to be careful not to reward the dog for aggressive behavior,” she emphasizes.

In some cases, the dog who is fearful of one individual will be fearful of others who physically resemble that person. For instance, if a redhaired person, a small child, or a person in a particular uniform abuses the dog, then the dog may react fearfully to other redheads, other children, or other people in those uniforms.

Effective treatments

Treatment for fear aggression is usually effective. These efforts need to focus on eliminating the person's negative behavior that creates the fear and replacing it with positive actions, activities, and rewards. When that's done appropriately, the aggression will disappear.

The dog must learn not to fear the person who elicits the fear response. Thus, “In a family situation, the only person who pets or pays attention to the dog should be the one who elicits the aggression," Dr. Houpt explains. That person should do nothing to make the dog feel fearful and should instead focus on reward and positive association-based activities such as feeding the dog, providing treats, taking him for walks -- and delivering no punishments. If there are negative behaviors requiring correction, another family member, whom the dog does not fear, should take the remedial action -- and the action should not be physical.

During retraining, other family members should avoid paying much attention to the dog and instead let the feared person be the dog's center of attention and the one he must rely on for his needs. Those close to the dog may require special instruction to understand the need for this temporary distancing.

If the dog is so fearful of a person that putting on a leash or offering food triggers a snarl, another friend or family member can attach the leash and then hand it to the feared person once outside. When outside, the dog will be less aggressive, as he won’t feel trapped.

During these walks, the person should be firm but never threatening and should provide the dog his favorite food treat when a command is obeyed. Inside the house, another family member can give the dog a treat when the feared person enters the room. This makes a positive connection in the dog’s mind between treats and that individual. If the aggression threat is strong enough to trigger a bite, particularly toward a child, a muzzle may be needed temporarily.

If carried out for a few weeks, the practices outlined above should change the dog’s perception from fear to affection. The dog will come to see the once-threatening person as the one who now must be relied on for the most pleasant parts of his life, which include being fed, receiving food treats and petting, and going outside.

In many instances, use of a dog anti-anxiety medication can speed up the retraining process. Psychoactive medications prescribed by a veterinarian are usually benign and don’t harm the dog.

Reprinted from Cornell Univ College of Veterinary Medicine's Dog Watch Newsletter, MAY 1999