First thing I would try is to immediately stop the fight and put them each in time out. Sometimes going to jail is enough. I have two females who will once in a while get into it and they have to be reminded that they will be in solitary confinement if they do not behave appropriately. It always works. In the beginning they fought often...now it is once in a blue moon.
I hope that might help you.
One thing I would caution you about is to never leave them alone together. When you go out, you really should separate them. If not, you could come home to a disaster.
If that does not work, I would suggest a behaviorist...NOT a trainer....but someone who can evaluate the behaviors and work with you on ways to change them. Good luck!