How to Stop Aggressive Behavior in Dogs

barking dogs
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When your dog regularly growls, snaps, or bites, you have a serious behavior problem on your hands. In fact, aggression is the top reason why dog owners seek the help of a professional dog trainer. And it's not just the "scary" larger breeds of dogs that are prone to aggression; any breed is capable of becoming aggressive under the right circumstances. Although it can't be cured overnight, there are steps you can take to curb the aggressive behavior and help your dog remain calm.

Why Do Dogs Behave Aggressively?

Aggressive behavior in a dog refers to any behavior connected with an attack or an impending attack. This includes becoming still and rigid, growling, baring teeth, snarling, lunging, and nipping or biting.

Your first step toward stopping this behavior is to figure out what's causing your dog's aggression. Some dogs growl when someone approaches them while they're eating or chewing a bone, for instance. Others react aggressively toward children or strangers.

The aggression doesn't have to be directed toward a person either. Some dogs become aggressive around other animals, only specific animals (cats but not other dogs), or toward inanimate objects, such as wheels on vehicles or yard equipment.

Additionally, some dogs are bred for traits that actually promote aggressive behavior. For instance, terriers are bred to attack rodents and other small animals, while "guard dogs," like Dobermans and Rottweilers, are bred to protect property and people. These are natural instincts that require owners to ensure that these types of dogs display aggression only in the appropriate situations through proper training.

The key thing to keep in mind is that you can't come up with a plan to modify your dog's behavior until you know the reason behind it. The most common types of dog aggression include:

  • Territorial aggression: The dog defends its space or your home from what it deems to be an intruder.
  • Protective aggression: The dog protects members of its pack against another animal or a person. Mother dogs are also extremely protective of their puppies and may become hostile toward anyone who goes near them.
  • Possessive aggression: The dog protects food, chew toys, bones, or another object of value to it.
Possessive aggression
Possessive aggression. Elvira Kolomiytseva / EyeEm/Getty Images
  • Fear aggression: The dog tries to retreat in a scary situation but then attacks when cornered.
  • Defensive aggression: Similar to fear aggression—the dog attacks in defense of something rather than trying to retreat first.
  • Social aggression: The dog attempts to earn the alpha spot in a group. Dogs that are not socialized properly with other dogs and people may also exhibit aggression.
Social aggression
Social aggression. Tim Harrison/EyeEm/Getty Images 
  • Frustration-elicited aggression: The dog behaves aggressively when it's restricted on a leash or in a fenced yard. Sometimes a dog may become overly excited, such as before a walk, and nip its handler.
  • Redirected aggression: The dog might become aggressive toward a person who attempts to break up a dog fight. It may also happen when the dog can't reach the target of its hostility, such as a neighboring dog on the other side of a fence.
  • Pain-elicited aggression: The dog shows aggression when it's injured or in pain.
  • Sex-related aggression: Two male dogs become aggressive when vying for the attention of a female dog.
  • Predatory aggression: The dog behaves aggressively without much warning when exhibiting predatory behavior, such as when chasing wildlife. This instinct may become a serious danger when a child is playing chase with the dog. It may start out as an innocent game, but some dogs may quickly turn on and possibly bite the child.
Predatory aggression
Predatory aggression. Kypros/Getty Images 

How to Stop Aggression

Noting when your dog becomes aggressive and the circumstances surrounding the behavior plays an important part in determining your next step. There are a number of ways you can manage the hostility and help your dog remain calm, but it will take time, consistency, and possibly the help of a professional.

See Your Vet

Dogs that aren't normally aggressive but suddenly develop aggressive behaviors might have an underlying medical problem. Diseases that can cause aggression include hypothyroidism and congenital or acquired neurological problems such as encephalitis, epilepsy, and brain tumors.

Talk to your veterinarian to determine whether this is the case with your dog. Treatment or medication may make big improvements in your dog's behavior.

Call in a Professional Trainer

If your vet has ruled out a medical problem, it's time to call in a professional dog trainer or behaviorist. Because aggression is such a serious problem, you shouldn't attempt to fix it on your own. A professional can help you figure out what's causing your dog's aggression and create a plan to manage it.

To find a professional dog trainer or behaviorist, ask your veterinarian for a referral or contact the Association of Professional Dog Trainers.

Create a Plan

Your trainer can help you figure out the best approach for managing your dog's aggression. In most cases, you'll use positive reinforcement (e.g., lots of treats and praise) to teach your dog new behaviors.

For example, if your dog is mildly aggressive toward strangers, start off by standing far away from someone your dog doesn't know. You should be far enough away so that your dog doesn't start to growl or snap. Then give it lots of treats and praise as you gradually decrease the distance between your dog and the stranger, continuing to use positive reinforcement.

Ideally, your dog will begin to learn that strangers equal treats and you'll see a reduction in its aggression. This same procedure can work for getting your dog used to a variety of other situations.

Avoid Punishment

Punishing your dog for aggressive behavior usually backfires and can escalate the aggression. If you respond to a growling dog by hitting or yelling, it may feel the need to defend itself by biting you.

Punishment may also lead to your dog biting someone else without warning. For example, if your dog growls at children, it's letting you know that it's uncomfortable around them. If you punish your pet for growling, it may not warn you the next time it gets uncomfortable. It may simply bite.

Administer Medications

In some instances, training alone is not enough. Dogs that are aggressive because they're fearful may need medication to help manage the problem. Talk to your veterinarian about your options.

Handle Unavoidable Situations

Finally, you need to consider whether your lifestyle allows you to stick with a plan. For instance, if you have a dog that growls at children and you have kids, it's impossible to avoid the situation that brings out its aggression. In this case, the best option for you and your dog may be finding it a new adult-only home.

If you suspect your pet is sick, call your vet immediately. For health-related questions, always consult your veterinarian, as they have examined your pet, know the pet's health history, and can make the best recommendations for your pet.