What to Do about Your Dog’s Aggression

By Sarah Hodgson from Puppies For Dummies, 2nd Edition

If your dog shows severe aggression — bared teeth, hard eyes, a growl that begins in the belly, and a bite response you’d expect from a trained police dog — you need to address the issue immediately. These personality disturbances are seen very early, usually by 4 months of age.

No need to panic if your puppy sometimes growls at you or barks at the mail carrier. These are normal behaviors that you can work to control with proper training.

The solution may be as easy as attending a puppy training class or you may need to consult a professional animal behaviorist or trainer.

Fixing the problem that leads to aggression or euthanizing the dog are your only options — passing along an aggressive dog that may harm someone is irresponsible and unacceptable.

Some types of dog are bred to be protective, and these breeds need to be trained early on. And, every dog needs to know that you’re the boss so that they feel confident that you can handle any situation.

A dog who shows signs of aggression is generally trying to accomplish something:

Be the leader of the pack: This dog takes on responsibility for protecting her charges — including her people. You need to let her know that you have everything well in hand — that you give the commands — and she just needs to follow your lead.
Guard territory: Confrontations with other dogs often are triggered when they meet on territory they both consider theirs. Dogs also protect objects they perceive as theirs — food engenders a protective attitude in some dogs.

The letter carrier who approaches the house, is barked at, and then leaves makes your dog feel victorious — it’s the perfect reinforcement cycle.

Your role is to assert yourself by keeping your puppy off the furniture and by sticking to a regimented training program that has her wait while you go through doors first, makes her heel when you walk in public, and has her sit when greeting people — inside the house and out.
Deal with fear: A shy pup’s timidity in new situations may turn into overwhelming fear and trigger a defensive aggression.

If your puppy shows signs of fear with company, such as flight, approach-avoid, or protective barking from behind your legs or furniture, you need to be understanding and patient. You can’t correct a fearful puppy; doing so only increases her fear. You can’t soothe her either because your attention just reinforces her behavior. You ignore inappropriate behavior and be ready to praise or treat when your dog sits calmly.
Revert to predatory roots: Predatory aggression is an instinctive behavior from times when dogs were wolves and hunted for survival. Most dogs still possess a chasing instinct. Even though breeders have suppressed the drive to kill in most breeds, some instinctively chase and, in some instances, kill small game.

If you have a chaser on your hands, rehabilitation can be quite a project. Instincts hold a powerful sway over behavior. Focused play gives chasers an outlet, but you need to correct their impulses with other animals or children to discourage interactive chasing rituals.

Psychotic puppies are very rare, but they do exist, mostly as a result of poor puppy-mill-type breeding. At unpredictable intervals, a psychotic puppy growls fiercely from her belly at non-threatening events such as someone walking by or turning the page of a newspaper. At other times, the dog is perfectly sweet — a Jekyll-and-Hyde personality.

Psychotic aggression is both frightening and tragic because nothing can be done to alter the dog’s development. If you suspect that your puppy is displaying erratic viciousness, speak to your breeder and veterinarian immediately and call a specialist to analyze the situation.

If you have a puppy that shows aggression, ways to asset your dominance and keep her aggression in check include

Keep her off your bed and off the furniture. An aggressive dog thinks it’s her duty to protect you or keep you in line. The first step in resolving this issue is to take over the high sleeping ground.
Ignore her bids for attention and give her commands she knows. Give your dog simple commands, such as Down, throughout the day.
Hold training sessions each day. Do three to five ten-minute lessons each day, reviewing known commands or teaching a new skill.
Stop free feeding. You decide when your canine gets her chow, she doesn’t get to choose.