benjammin,

Can you give me a few general details as to your location? Are you in an urban, suburban, or rural area and which county in Washiington are you located?

As a pass president of a ranchers association in the State of Washington, there are legal options for taking action depending on your location, open range area or not.

We had a real problem with people relocating from the city and letting their dogs, some very expensive and beautiful dogs, run loose and harrassing live stock. After checking with the county attorney, we had a number of options. Some of those options let the ranchers take the matter in their own hands. One variant was rather gruesome but humane. Afterward, everyone knew what happened to the dogs, where it happened, and who did it. At the same time, this action proved the guilt of the owner in letting the dog run loose and protected the ranchers from liability. This action also put the burden of proof on the owner that his dog was not guilty. If the owner did take legal action, they ended paying the rancher damages. This action takes balls but to this day, no one lets their dogs run loose in that part of Klickitat County.

Again, I am a long time dog lover and trainer. Try dealing with the owner. If that does not work, once you know your legal options, you can inform him of the consequences to his dog if he does not take corrective action.