Introduction
All breeds, ages and genders of dogs can become aggressive. However, very few dogs are born aggressive, and frequently aggressive behavior in dogs is normally a direct result of something else.
Common Causes for Dog Aggression
Aggression in dogs is part of the normal range of canine behavior in many cases and is strongly influenced by breed, sex, early socialization, handling, individual temperament, genetics and other variables. It is possible for underlying medical conditions to cause or contribute to aggression, although this is rare. Still, medical causes of aggression (such as pain or neurological disorders) must be ruled out before an appropriate treatment protocol can begin.
Breed Susceptibility
When humans started breeding companion dogs, they did so in a manner that would consistently produce desired traits. The current range of canine breeds is a direct result of human manipulation and breeding for these various traits. Some breeds were bred to be pampered, gentle and tolerant. Other breeds were bred to protect flocks or herds, or for family protection. Some breeds were bred for their ability to track and hunt birds, wild boar, rats or fox. Others were bred for size, or smallness, or coat, or cuteness. Dogs bred for aggression (which they never should have been), may naturally have a tendency to be aggressive. Most breeds commonly associated with aggression towards people (“pit bulls,” bull dogs, others) actually were bred to be extremely trainable and restrainable by people, but were taught to be aggressive to other animals.
Behavioral Causes
No matter how gentle a puppy is, abuse, mistreatment and neglect can cause that dog to suffer behavioral problems, including aggression. Dogs that are raised without proper socialization, nutrition and affection will not know how to act appropriately in social situations involving people and/or other dogs. It is extremely sad to see fear or other forms of aggression in a dog because of an abusive or neglectful background.
Medical Causes
Medical causes of canine aggression are uncommon but may include: pain, head trauma, swelling of the brain, rabies, distemper, epilepsy, arthritis and other neurological or painful disorders. Painful dogs may bite their owners without really knowing what they are doing (for example, after being hit by a car or attacked by another dog).
Outlook
Understanding the cause of canine aggression is essential to assessing and helping a dog and its owner in any given situation. Professional help from a veterinarian and a skilled behavior expert are key components of a healthy recipe for treating aggression in our companion dogs. While this condition can be extremely frustrating for owners (and no doubt for affected animals as well), there are steps that can be taken to address the situation. Euthanasia should never be an automatic “treatment” or “solution” for behavioral disorders in our pets.