I thought maybe some people subscribed to this thread might be able to use some tips for breaking up fighting dogs:
First, don't get your hands involved!
The first and best tactic that I know of is to grab a chair and use it to pin one of the fighting dogs. Of course, when one dog is incapacitated, the other dog will attack that dog, so only do this if you feel like 1) you can pin the dog effectively and 2) you're pinning an aggressor that is bullying a submissive dog that you think won't attack back.
The other, less good tactic is to use a blanket if there is one nearby to cover the dog you want to grab. I've only heard both of these tactics recommended and never had to use one of them, but I would go for the chair tactic every time. I would NOT try to use the blanket tactic unless it was a pair of very small dogs that you think you can grab with a blanket. I really don't like the idea of the blanket solution because it gets your hands too close to the "business end" of the fighting dogs.
I've heard that spraying water doesn't work, and anyways, most fights probably happen in the home, where you don't have access to a garden hose and wouldn't want to use it anyway.
Sadly, I think the best thing is to just let the dogs fight it out, since most of the time they won't fight to the death. You'll have to pay to get their injuries fixed, but it's better than paying to have your injuries fixed.