Priority #1 is you and your dogs, Gabbie.
You don't know what might happen to you when you're trying to separate fighting dogs. If you can't keep the unwelcome visitor out or repel it, what choice do you have?
If a fight starts, stay calm (or as calm as possible) and wait your opportunity to grab one (the aggressor if possible) by the collar near the ear (so it's hard to bite you), reef it out of the brawl and hang on as if your life depended on it.
Some free advice that I hope you never need to use.
Thanks Mr R and I hope I don't need to. Yep don't want any fighting, though mine have had a dust up or two over a bone, imagine it over food , which I quickly stopped via the hosing of them or picking up their water bucket and throwing water over them, cools the situation pronto.
Here's a pic, taken a year ago of the the back fence of my yard which the intruder somehow got through, it's 6ft high for a start, the swine chewed a few of the palings then dug, it's been fixed.