Might be good idea to have OC spray and or an air horn as an alternative/first response for just such an occasion.
haha where are you from? I would shoot any stray that even thought about getting too close to me or my dog. as long as you are sure to discharge the bullet so it hits the ground and doesnt end up in someones window i see no reason not to. My grandpa always says "A loafing dog ain't worth a shot, but i'll waste one anyways"