We once had the same happening here a few years ago. Two GSDs attacked our pyrenees, one his back end one the front. Fortunately Troy had no problem to ward them off (pyreneans are bred to fight wolves and bears after all, so two shepherds were no challenge really) and one was limping and the other bleeding from the shoulder (Troy was unharmed). But the guy with them said that other dogs normally submit or run away and that he had never seen any stand up to them like Troy did... So obviously he let his dogs bully other dogs on a regular basis! We have never seen them again in the area... maybe (and hopefully) he (and his dogs) have learnt a lesson.
I would also report him to the dog warden so they can at least have a word to keep the dogs safe.
Vera
