Unlike dominant-aggressive dogs, which usually assert themselves with family members, most fear-aggressive dogs target strangers--such as delivery people or children.

Fear-aggressive dogs often send out ambiguous "body language" messages. They may crouch submissively and tuck their tails, but the hair on their back is usually up and they often growl and show their teeth. Fear-aggressive dogs learn that a good offense is the best defense.

Even though fear-aggressive behavior is self-reinforcing (in that most people go away--exactly what the dog wants), desensitization and counter conditioning techniques can reduce the likelihood of fear-related aggression. However, any dog that has bitten once is capable of biting again. So owners of fear-aggressive dogs always face the risk of injury to themselves and others both during and after treatment.

If you are concerned that you might have a fear-aggressive dog, consult your veterinarian. They may recommend medication as well as an animal behaviorist for treatment.