Molli and Sammy have a couple fights every week. I don't think they've figured out who is the dominent one yet. I usually have to end up pulling them apart because Sam is so big compared to Molli. I was told to grab the back legs of one dog and pull them away. I don't know how easy that would be for you, because you've got bigger dogs. I think you handled it very good. Freaking out won't do any good, but keeping your self calm will help you break it up easier.