Aggressive Dog Behavior: Why My Dog Keeps Biting Me and How to Stop It
Whether directed at you, a family member, a stranger, or another animal, an aggressive dog is not only frightening but could also lead to injury or legal issues. Although it might seem that a dog is aggressive without cause, most show this behavior due to a few basic reasons: they are sick, frightened, possessive, or frustrated.
Understanding why your dog bites, growls, or behaves aggressively is the first step in solving this dangerous behavior. Many owners assume an aggressive dog is uncontrollable and needs rehoming or euthanasia. However, resolving the underlying issues often reduces or eliminates the aggression.
Here's what to know if your dog becomes aggressive towards you, family members, pets, or strangers.
Signs of Aggression in Dogs
First, it's important to recognize the signs of canine aggression, as few dogs bite without first showing escalating behaviors. A dog displaying aggression may:
Stand very still with a rigid posture
Make direct eye contact and hold it
Flatten the ears against the head
Growl or bark in a threatening tone
Snarl
Curl its lips to expose its teeth
Lunge forward without making contact
Snap without making contact
Bite lightly so as not to break the skin
Bite hard enough to break the skin or leave a mark
Depending on the stimulus's cause and intensity, a dog might display all these behaviors or just provide a warning by growling, snarling, showing aggressive postures, or exposing teeth without biting.
Reasons for Dog Aggression
Understanding why your dog acts aggressively helps you create an effective plan to stop this behavior. Dogs usually show aggression for one or more of the following reasons:
Illness and Injury
Medical conditions can make dogs aggressive. If a dog that has never shown aggression suddenly begins growling, snapping, or biting, it might be due to illness or disease.
Pain is an especially common cause of aggression in dogs.1 Your suddenly aggressive dog may have an injury or an illness that's causing major discomfort and stress. Some possible causes of pain include arthritis, bone fractures, injuries, and tumors.
Other illnesses may affect your dog's brain, leading to aggression that seems unreasonable. Conditions such as cognitive dysfunction, brain tumors, and other brain diseases may cause the onset of aggression. These problems are more likely to occur in older dogs but can happen at any age.
If your dog is exhibiting sudden, unexplained aggression, talk to your veterinarian before attempting to address it as a behavior problem.
Fear
A fearful dog can easily develop aggressive behavior.2 Most dogs only exhibit aggressive behavior if they sense that they are in danger, cannot escape, and feel the need to defend themselves. For example, this may occur if a dog is backed into a corner with no way out, or if it thinks a hand raised over its head means it is going to get hit.
If your dog is a rescue dog that exhibits more aggressive or fearful behavior than is normal, it may have been abused, neglected, experienced a traumatic event, or not properly socialized as a puppy. Any information you can get from the organization where you adopted the dog could help you determine the best way to handle the situation.
Sometimes rescue dogs need obedience training with an instructor who specializes in teaching dogs that have been abused or those that have not been properly socialized. In some cases, you may be able to manage your dog's fear on your own with training and patience. You can speak to a veterinarian about the best course of action.
To avoid provoking this type of aggressive behavior, approach unknown dogs carefully (better yet, let them approach you). Train and socialize your dog to help prevent fear down the road.
Possessiveness
Possession aggression, or resource guarding, occurs when a dog is possessive of something. This is often food, toys, or some other object of value. A dog that exhibits possession aggression may growl if someone approaches his food bowl or gets too close when he is chewing a favorite toy.3
A dog may also bite or show aggression to a stranger who steps into your home or onto your property, which is the dog's territory. This is a common scenario with dogs who "hate the mail carrier" or bark violently at people just outside the property boundary or fence.
Resource guarding is also a common cause of aggression towards other household pets. Some dogs will growl, snap, or bite other animals in the home who approach the dog's food bowl, bed, or favorite toy.
The degree of aggression may vary from one dog to another and between objects. For instance, your dog might not care if you sit down and pet him while he chews a rubber toy, but he may turn and snap at you when you do the same thing while he gnaws on a dental chew. It all depends on the value that the dog attributes to each object or resource.
Frustration
Aggression that's caused by frustration is often referred to as redirected aggression or barrier frustration. It occurs when a dog is frustrated at not being able to get to something and takes its frustration out in another way.4 This type of aggression is common in dogs that spend a lot of time tied up, restrained on a leash, or behind a chain-link fence.
For example, a dog that's chained in a yard may spend the day straining to get to a dog that lives across the street or in an adjacent yard. The restrained dog usually barks and growls more fiercely as the frustration grows. When the owner approaches, the dog may redirect its frustration and bite the owner. Redirected aggression may also result in the dog lashing out at another family pet, whether canine or feline.
What to Do If Your Dog is Showing Aggression
Be careful not to misinterpret your dog's aggression. Always see your veterinarian to rule out a health or behavioral issue before you assume you know the reason for your dog's aggressive behavior. Otherwise, attempts at corrective measures could make the problem worse.
You may be tempted to try giving your dog medication to relieve pain or calm them down, but this is something you should not do. If your dog is unwell, you'll need to know exactly what is wrong before starting any treatment. Only a veterinarian can advise what medications are appropriate for your dog.
If your vet has ruled out medical issues and you still can't get to the root of your dog's aggression, it can help to consult a professional. Find a dog trainer or behaviorist who specializes in canine aggression. These specialists have knowledge and training methods that can be very effective even with dogs that seem to be "lost causes."
