Causes of Aggression in Dogs

A dog growls, postures and snaps. They are labeled aggressive. Aggression is the intent of the dog to do harm. Bites can occur as a result and most frequently to children, according to Dog Bite Law, but aggression can be focused on any human, dog or other animal.

There are multiple causes of aggression in dogs. Let's take a look at the most common.

Personality conflicts

Often in my work training reactive and aggressive dogs, I see personality conflicts and most often between two females in the same household. Personality conflicts arise intra-household (within the household) or inter-household (outside of the household). If it occurs once, it will occur again and the key to change is proper implementation of a systematic tolerance and acclimation training sequence for intra-household cases. Outside of the home with aggression shown to strange dogs takes prevention, management and a program of desensitization.

Barrier Frustration

Frustration is caused when a dog cannot escape. A barrier could be in the form of a dog being tied out or tethered and getting little to no social interaction, or it could come in the form of leash aggression or separation anxiety. The bottom line is the dog cannot escape. This causes the dog to resort to attack out of increased anxiety, stress and nervousness. Just having a barrier coupled with an incident causing over-stimulation or over-excitement can cause an adrenalin rush and a resulting aggression. The dog has been put in a situation where it cannot be successful.

Redirected or respondent aggression

Redirected aggression is one of the hardest to rehabilitate. The dog works itself into a panic and redirects aggressively to whatever target is in the way, whether that means a leg or a leather couch. The dog is in such a high state of anxiety caused by a specific stimuli, such as the mailman's arrival, a squirrel, another dog, or fence chasing that if anything gets in its way, the result will be a redirected bite in response to the overly stimulating trigger. This type of dog is dangerous and volatile.

Predatory aggression

Dogs who fulfill the predator sequence of eye, stalk, chase, grab, shake, kill become predators. The more they do it, the more they might aggress and redirect to a child or animal, small dogs included who sound or move like prey. This is called predatory drift. These dogs are also hard to rehabilitate because the act itself is instinctual, the need to survive.

Medically caused aggression

Medications and even vaccines can change a dog's perceptions or make them highly sensitive and cause aggressive incidents to occur. Some medications can cause a dog to become irritable and result in aggressive behavior. Pain may also cause an aggressive response as the dog tries to make the pain go away.

Fear

Fear-induced aggression is one of the most common forms of aggression. A dog is cornered or put into a fearful situation and gives a warning or a growl. The growl is ignored, the dog air snaps or worse bites because they perceive instinctively that they are fighting for their life.

Fear can be caused by an over-the-top genetic disorder, fear-inducing incidents during the informative stages between birth and 16 weeks, or abuse. Most dogs, if they cannot escape and are put in a bad situation, will aggress. It becomes a matter of survival for them.

Dogs usually default to four behaviors fight, flight, fool around or freeze. A dog who chooses to fight is labeled aggressive, but flight, fool around and freeze can signal an attack about to occur.

Fear posturing is shown in a dog who crouches, hides, or tucks a tail between its legs. Other postures can be keeping head low, showing whites of eyes and having ears pulled back. Movements indicating fear is if a dog walks backward or moves away or even sniffs all as a displacement behavior in times of stress.

Resource guarding

Dogs can resource guard food, locations and people. If the behavior is strong, a dog will even guard air molecules or shells on a beach, anything it considers fair game for challenge. Dogs who resource guard are threatened by something in the environment that might take away a prized possession, food, even their people. The dog's bed, the couch, a rug, the food bowl, the treat bag, their person are all reasons for aggression.

Social deficits

If dogs have been isolated during the informative social weeks between birth and eight weeks or been taken away from their mothers and litters too early, they could have social deficits meaning they will be catching up their entire lives. In some cases, social deficits can be enough to cause aggression, because exposure to people, other dogs or animals has been minimal to none.

Normal aggression

Maternal instincts or protection of puppies would be an example of normal aggression. Another example would be protection of owner and territory, or family and den in wild terms. If a burglar or stranger comes unannounced, this is cause for territorial aggression. The drama created by multiple dogs would also be considered normal aggression. Dogs act differently in groups and may show aggression due to over-excitement and stimulation. Play can stimulate aggression especially if rough play occurs or the dog hasn't learned how to play properly.

Territorial

Territorial aggression becomes problematic when it becomes obsessive or inappropriate. Alerting an owner to a stranger on the territory is normal behavior, but aggression at every passerby, visitor or dog is not.

Determining the cause of aggression is the first step to changing the behavior. In aggression cases, it is always advisable to precede any training with a medical exam by a qualified veterinarian. Aggression can be linked to medical causes, pain, and conditions. Determining medical causes allows for proper treatment and even changing behavior is some cases. If a medical report comes back negative, then the behavior change plan can begin with the commitment to rehabilitate the dog.