This week we have covered most kinds of dog-dog aggression and reactivity.  Sometimes it is caused by fear, sometimes frustration, and other times due to complexities in the household.  But there are times, albeit very rarely, when dogs are aggressive to their own kind seemingly without reason, and that is what we call idiopathic aggression.  It is important to note that “idopathic” does not mean without cause, it means of unknown cause.  Idiopathic aggression is created in the dog by something–we just don’t know what it is.  Here are some potential causes:

Health problems like epilepsy or thyroid problems can and often do create aggression problems.  I insist that all owners coming to me with their dog’s aggression problems have the dog’s thyroid checked.  In the case of one dog I worked with her aggression was purely caused by hypothyroidism; once she was on medication she went back to normal. 

Genetics can and do contribute to temperament issues of all kinds, including aggression.  If you choose to buy a puppy from a breeder only choose a breeder whose dogs have outstanding temperaments.  This not only helps you out in the long run, it helps support breeders who are breeding ethically. 

Poor training or behavioral intervention can create aggression problems where there are none.  Take a dog that is mildly uncomfortable around other dogs, correct him for growling a few times, and you’ll have a dog that snaps at his peers “for no reason,” in no time flat.  Trainers that have no business treating aggression can make your dog’s mild issues much, much worse, so be careful when choosing professionals.

Treating idiopathic aggression is difficult because if you can’t identify the trigger you can’t desensitize the dog to the trigger.  If the dog is only aggressive toward other dogs (not people) you can decide that “dogs” are the generic trigger and get to work on replacing the existing aggression with a more appropriate, incompatible behavior.  As you might have guessed from reading my previous posts, my recommended method for this is Grisha Stewart’s BAT protocol for fear and aggression

Lifelong management is necessary for all kinds of aggression but it is the most important for idiopathic aggression.  Making sure that your dog simply does not have opportunites to engage in aggressive behavior is part of your job as a loving and responsible dog owner.