What should I do about a rottweiler chasing my diary goats?
What should I do about a rottweiler chasing my diary goats? Dog Breed Discussions
My suggestion would be to buy or borrow a semi-automatic BB gun powered by CO2 cartridges. Next time he shows up let fly at him as fast as you can shoot accurately and don't stop until he is out of range or out of sight. Give him no more than two chances to learn; if he still comes back, it's time to use the shotgun. I had the same problem with stray dogs attacking my rabbits in their hutches and since I live in a city I couldn't use a real firearm to apply the "Final solution". The BB gun worked like a charm!