UPhunter makes a good point. Here in Michigan you can get in big trouble shooting someones dog. My best friend had the same thing happen to him in 2002 that is happening to you. The thing was that coyote "hunters" were running thier dogs on private property out of season and the dogs were actually running the deer and not the coyotes. After several weekends of the dogs running deer and repeated attempts to get the owners to not run thier dogs on my friends property, he couldn't take it any more and shot one of the dogs. The owner came looking for it and picked up his dog. As my friend and his hunting partners were going to leave the property, the dog hunters were waiting for them at the entrance and were looking for a fight. The State Police, Sheriff and Game Warden were all dispatched and I guess it was a pretty tense situation. In the end, my friend was found guilty of killing the dog, and was sued by the dogs owner. He wound up having to pay for his lawyer (criminal and civil trial), court costs, fines and restitution to the owner. The total court related cost was almost $20,000. It also almost cost him his job as a cop. You might want to keep that in mind before you exhaust all other options.