When I lived in the jungle of Thailand, there was this pack of about 3-4 dogs that would roam the backwoods, never on the street. I had a dog of my own at the time so it could actually be quite dangerous for her if they got in the yard. They really weren't all that interested in my yard unless I had garbage out so I just removed that and they didn't really ever come back. My dog was of course standing up for and guarding our property, but I wouldn't have fancied her chances against 3 grizzled jungle dogs.