There’s Always a Reason For Aggression

The other day someone told me that her dog attacked another dog,  “for no reason at all.” I’ve heard others say that their dog bit someone, “for no reason at all, just out of the blue.”  When a dog bites or attacks a person or another dog, the reason may not be apparent, but there is always a reason.

The reason may be internal to the dog or some external trigger. A formerly docile older dog may become aggressive because of arthritis pain, and attack his owner when the owner shoves him off the couch. A dog experiencing a sharp flair of pain may associate the nearest object, (human, animal, or inanimate), with that pain and attack that object. Brain tumors, seizures, and hormone or blood sugar imbalances can trigger aggression. Past experience may trigger fear related aggression reactions.

For example, imagine a dog whose previous owner repeatedly beat him with a broom. The dog runs away, is picked up as a stray, and is adopted into a loving new home. The hapless new owner brings out a broom to do a bit of sweeping. The sight of the broom triggers intense fear and the dog attacks the new owner. Not knowing the dog’s history, the aggression appears to be, “for no reason at all.”

Aggression is often the result of a dog guarding what it considers to be a valuable resource, (remember that value is in the eye of the beholder). A dog may decide that a particular object or location, at a particular moment and in a particular situation, is valuable and may use aggression to guard that resource. The resource may not be apparent to us. It could be a bug on the floor, a spot in the sunshine on a cold day, a dust bunny, a line of sight from the kitchen to the front door when the mailman usually appears, a bone hidden under a cushion, or almost anything. If the dog feels that his possession of that resource is threatened, he may become aggressive.

Dogs may perceive a threat from human body postures or actions. For example, in dog body language, unless preceded by clear play signals, looming over and putting the front paws on another dog is a seriously threatening posture. From a dog’s perspective, the stranger who walks up to a dog, leans over him and hugs him is a clear and imminent threat. A dog that was not exposed to lots of this as a puppy is likely to bite the stranger in the face. To the casual observer unschooled in dog body language, the attack was, “for no reason at all.”

If your dog is suddenly aggressive, you need to be a detective and uncover the reason. Start with a trip to the vet to check for underlying pain or other health problems. Try to reconstruct what happened and find the trigger. A video of an aggressive incident can be immensely helpful. If you need help identifying the trigger or changing your dog’s reactions to the trigger, contact a professional trainer or dog behavior counselor.

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