Aggression in dogs is defined as a threatening or harmful behavior directed toward another living creature. This includes snarling, growling, snapping, nipping, biting and lunging. Dogs that show such behavior are not abnormal; they are merely exhibiting normal species-typical behavior that is incompatible with human lifestyle (and safety). There are many reasons why a dog will act aggressively toward strangers or even his owner.

The first step, when attempting to find out why your dog is being aggressive, is to take him to your veterinarian. Some veterinarians will visit you at your home - but dogs tend to be more aggressive on "their" territory.