Bulldog Mix Aggression

Question
I have a 2 year old bulldog mix.  When he was about one year old, he started acting aggressively towards some other dogs.  He doesn't always act like that, and he doesn't do it to all dogs.  He also is not aggresive to dogs who are much smaller than him.

He is not aggresive to the point where he will bite another dog; he just barks and growls.  

When I take him to the dog park and he acts aggresively, I will put his leash on him and walk away for a few minutes.  Once he stops whining and sits still then I will let him go.

What can I do to break him of his aggression?

(He is very sweet to all normal people.  He will growl at mentally unstable people.)

Answer
Bulldogs are a breed which isn't always good with other dogs, but I would call what you describe - barking and growling, but not biting as reactive instead of actually aggressive. He may be intimidated by other dogs or may simply play inappropriately. Not easy to know without seeing the interactions. A great book for you to read is "Click to Calm" by Emma Parons. It's got wonderful strategies for helping reactive dogs. And I'd probably find other ways to exercise him than going to the dog park. He might put other dogs in jeopardy, and if he tries his act on the wrong dog, he could be injured. Not all dogs really interact well enough to be good dog park material. Part of the problem is that even if you have good control of your own dog, many dogs in dog parks aren't under good control. i'd look for a good positive instructor to help him learn other ways to relate to dogs. Sandy Case BFA MEd CPDt www.positivelycanine.com