id say get a hose and spray them down when they get on ur proptery they should learn fast and if they dont ull have to call the shelter and if they dont do anything call the cops and they will shot the animal instead of u getting the cops called on u if it was really a house pet....... if found out that water works great did it to cats that where trying to get at some fish i had............ i ended up just leaveing my pit out side and found a couple dead cats in the back yard but they eventualy got that if they went past a certain spot the dog could get them so they all would sit on one side of the fence stareing into the pond.......... i dont condone useing dogs as cat control but something had to be done as i was finding my fish with bite marks and scratches all over......... after awhile the dog started to like to swim and couldnt get it out of the pond..........