Siz. Could you possibly borrow a paintball gun from one of the neighborhood kids. Shoot the dog with that and it may sting enough to deter him from coming back. Nonetheless it will mark the dog for animal control. Then should your neighbor question you as to why you did that explain that it killed one of your PET chickens and the next time you will use a real gun. Even though you have no intention of actually shooting it just the threat may be enough to prevent them from letting it run loose.
Just thinking out loud here. Sorry for your loss.
Just thinking out loud here. Sorry for your loss.