I'm so sorry this is going on! If the fights are this bad though I would contact a professional trainer or bevaiorist RIGHT AWAY!

You shouldn't be breaking these fights up unless you can do it without any contact (like a loud noise or spraying them with water) because you could end up with something broken! My advice is to keep these dogs seperated until you can get a trainer or behaviorist to give you some advice on the situation. I hope things work out- good luck! Let us know what happens.