Do you take your dog to dog parks? I get a lot of questions about whether I think dog parks are a good idea.
In general, no -- they're not usually a good idea. Most dog parks are an uncontrolled environment with no strict requirements on which dogs enter. There are usually signs posted -- no females in heat, no aggressive dogs, but sometimes these signs are either ignored, or owners don't recognize signs from their dog that a fight is about to break out.
At a recent training trip to a very popular dog park, I heard three distinct fights over a period of only 20 minutes!