although there are other ways to brake the fight, but I don't think it's animal abuse because your dad try to brake the fight unless your dad injured the dog.
To some it is but in all honesty i say it isn't. If he allowed them to fight it could potentially be dangerous to your dogs health so he may have been saving one of them.
Ask your neighbors to break the fighting with their bare hands...
My two male dogs were fighting so my dad broke them up with a broom. He was trying to break them up by moving the broom and hitting them. My nieghbors were making a big deal about it.
