Just an example a buddy of mine was out with his dog when a pit bull that was loose came up and attacked his dog and in effect him when he was trying to pull the two apart. My buddy pulled is 45 and shot the dog in the head. He then called the cops to report the incident and the cops agreed with his handling of the situation. If you feel that the dog is going to do damage to you, your animals or what ever on your own property, then you have to right to take it down. It is not a human and does not have the same rules associated with it.

I hope it does not come to that, but something tells me that either you tell the owner that is the direction things are headed or you will never solve the problem.