Don't know about Mi but here in Texas, the law says you're justified to use deadly force if you are in reasonable fear of death or grave bodily arm. It DOES NOT say the source of that threat has to be human! I once came within about 2 ounces of trigger pull of shooting a neighbor's dog that charged out in to the street as I was walking by. The ONLY thing that saved that dog was the owner witnessed the charge and called him off. He was very apologetic and agreed that if our roles were reversed he would have fired.