First, I'd like to say I'm sorry about the dogs fighting. It's never good when animals fight.

I, unfortunately, have no experience with dog fights. The only advice I can give is an example of what I've done with rats. When my rats have fought, play fighting gone a bit too far, I spritz them with a spray bottle. Usually, the two rats fighting run in opposite directions to get away from the spritz. However, with dogs, you may need more than a spritz of water.

Best of luck to you! I hope better advice can be given.