Until fairly recently, dog trainers and behaviorists would throw the word "dominance" around as if it were the nub of every canine social interaction. If a dog behaved aggressively -- especially about food, stolen objects, or resting places -- then he was dominant, a chest-beating George Foreman type from whom an owner needed to physically wrest control to become the "alpha pack leader." But the idea of the dominant dog has now fallen from grace, and any trainer who talks about it may very well get his or her mouth washed out with soap. I sometimes refer to this supposedly outmoded concept as "the behavior formerly known as dominance."
The new idea is that a dog who acts out toward his owner isn't really emulating his lupine ancestors; he's just fearful. Extremists claim that the past 12,000 years of selective breeding have erased the concept of pack structure from dogs' collective psychology; after all, groups of feral dogs don't have clear leaders. Also, many dogs that are aggressive toward their owners suffer from nervous conditions such as separation anxiety or noise phobia.
True, some dogs are just anxious or mistrusting. These dogs may show signs of behavior that's actually submissive, such as looking away and flashing the whites of their eyes, and may appear remorseful right after an incident. But do conflict and fearfulness explain all owner-directed canine aggression? I don't think so.
Some dogs who display aggression toward their owners aren't frightened or confused -- they're bossy. They seem confident and are affectionate almost all the time. Along with their self-assured nature comes territoriality, the occasional fight with like-minded dogs, and appreciable independence. When a dog with this kind of personality acts aggressively, I'm still inclined to call it dominance. This kind of behavior is more common in certain breeds (such as Rottweilers and pit bulls), which indicates there's a genetic component; it's most common in the evening (when the dog is tired and irritable); and it's usually exhibited by male dogs (neutered or otherwise). Dominant behavior is most often directed toward quieter, gentler people -- hardly the ones likely to generate fear and anxiety. It's also rarely displayed at visitors whom the dog hasn't yet sussed out, and when the dog's been away from his owners for a while, there's usually a "golden period" during which he's more tolerant. To my mind, all this is testimony to good old-fashioned dominance rather than anxiety or fear.
Whatever the source, in most cases, owner-directed aggression is easily treated. First, when you can, limit the situations that cause aggression. If the dog growls when you touch his food while he's eating, stop. (I don't like people to touch my food while I'm eating!) Then you need to establish control of the resources: Make him ask nicely. I call this the "Say please" program, and it should reduce aggressive incidents in a couple of months. If your dog snaps when you give him a rawhide chew, take it away and try again later. (If you gave your son a penknife and he stabbed you in the leg with it, you'd confiscate it.) The same goes for other resources, like food. There's no need to physically punish an aggressive dog -- but there's also no need to roll over and submit.