Fear/aggression behavior

Question
I'm planning on discussing this with my vet, but I'd like an outside opinion. I have a 2-year-old beagle/fox terrier mix. I got him from a shelter, and I know his living environment before then wasn't great (the guy who bred him ran over him with a car and broke his leg, requiring surgery).

As he's gotten older, he's become increasingly aggressive and dominant. He will growl and attempt to snap at people when he is on a leash. He will growl at/hump/bark at other dogs that challenge his dominance. He will growl/bark at people he doesn't know when they enter a room.

I have worked with two different behaviorists, and they believe his behavior stems from him trying to protect me.

I've become more concerned recently after he attempted to bite someone who had reached out to pet him and got very aggressive with some larger dogs at the dog park. He didn't bite them, but he chased them around, barking at them and bumping them to show he was the more alpha male. Their owners, rightfully so, were upset with my dog.

I'm worried that no matter how careful I am with him, there's going to be a situation that sets him off and something bad will happen. And the problem is exacerbated by the fact that, as a dog, he's a live wire. He's got two speeds: slow and 110 mph. And when he starts growling and being aggressive, there's very little I can do to calm him down, other than just removing him from the situation entirely.

My vet has previously suggested that euthanasia may have to be considered at some point. At first, I resisted that because I thought as he got older he might calm down, and because I wanted to try the behaviorists' suggestions. But those don't seem to have had much of an impact.

Any thoughts you could provide would be greatly appreciated.

Answer
You say you've worked with two behaviorists. What sort of recommendations did they offer you? Did they give you a training plan? What were their credientials? Were they Applied Animal Behaviorists or Veterinary behaviorist? Both require advanced degrees with a specialization in behavior. Some people refer to themselves as behaviorists, or behavior specialists who do not really have the credentials. I would be seeking the help of a person from one of the above two groups. Veterinary behaviorists can also prescribe anti-anxiety medications which can be very helpful in some cases - your vet can, too, but it's best to have someone who really knows which would work best for your dog, and can give you a training plan to go along with the medications. A dog who chases other dogs around a dog park bumping them has bad communication skills, but is not dog aggressive. Still, a dog who does that doesn't belong in a dog park. Frequently on-leash aggression towards other dogs is caused by being on leash and having very limited options, being excited and wanting to meet the other dog, or an owner who makes the situation worse by tightening up on the leash - sending a signal that something is "wrong". If he is snapping at people, people should absolutely not be allowed to try to pet him. That's your responsibility not to put him in situations where that can happen, since you know he is reactive. And I'd quit trying to frame this as a dominance issue. I suspect there are a lot of other things involved in this - being anxious, being overly-stimulated by situations which are more than he can handle, fear, and possibly resource guarding you (which is a bit different that trying to protect you.) Many of these things may be improved on by a good solid training plan, with support from an excellent trainer or a credentialed behaviorist who can see the dog and evaluate his issues (not really possible over the internet)He may never be a "dog park dog" or a dog who is friendly with strangers. You may always have to manage and protect him (and others) and keep up your training even when he seems to be "better." I can't say that euthanasia should NOT be a consideration. But I would seek the opinion of someone who is really skilled in behavior rather than from a general practioner vet (unless there's a lot more to the story than I've heard here) or from someone on the internet who can't evaluate him in person. Best luck. Sandy Case BFA, MEd CPDT www.positivelycanine.com