Its the dog owners responsiblility to keep control of his dogs. He obviously isn't. I'd get in touch with your local dog warden if have one. If not whatever person in that township that knows the law on dogs. Then take appropiate action to have him fined. Do this now, and take care of it before deer season. Also find out what rights you have if the problem continues. Be sure before you act. In NY you can't legally kill someone elses dog. Only a policeman, game warden or dog warden has that right. You don't want legal action taken against yourself. Once gathered all the facts take it from there, and do what you can.