I hear this a lot, and some of the explanations are very obvious. The dog was at a dog park or on a walk and got attacked and injured, then became dog aggressive.
We can clearly see an event that changed the way the dog feels about other dogs. We can still change that perception via training and group socialization (done correctly) but it helps to understand too how it happened.
There is a lot more insidious and cumulative damage done frequently to dogs where we see them become aggressive for no reason we can determine. No dog attacked them, nothing horrible happened to them, they used to like dogs and now they don’t.
I think this happens in a variety of ways. In the case of the dog who goes to the dog park and is fine for many, many visits over time then gets aggressive, it can be that this dog is being pushed far out of it’s comfort zone and nobody is advocating for it. Too rough of play, dogs not respecting body language that says “I need room”, things like that. When I say that I mean nobody is reading body language and seeing discomfort and disrupting that behavior and “sticking up” for the dog. Over time as this happens time and time again to that dog it finally feels like it must act aggressively to remove the problem since no humans are doing so.
Sometimes I see this as the human ceding key daily decisions to a dog that isn’t up to handling them, this dog needs more direction from the owner to establish a track record of the decisions being made that we like. These dogs get overwhelmed over time and feel stuck out in front and forced to make calls they don’t really feel up to making. We don’t want a robot dog but sometimes a framework where the dog can choose from fewer choices while we teach decision making is a good thing. Training wheels. 🙂
Another source of this can be a pain issue. Dogs are masters at hiding injuries and illnesses and can be very stoic, but that can make them very irritable in interactions with other dogs. We always want to rule out physical causes for aggression that seems to come up out of the blue.
If the dog has a pain issue then resolving that first is key, but other than that we see the vast majority of dog/dog aggression resolve nicely with the 1-2 punch of training and attending Group Socialization, where skilled trainers are watching body language and advocating for all dogs in the session.
If your dog is dog aggressive, a good step for resolving this would be to contact a local IACP trainer, ideally one that also runs a group socialization class. Contact Redeeming Dogs if you need that help locally in the Dallas Fort Worth area, or need help finding such a trainer to help you. So many times this is a fixable problem with some knowledge and commitment.
