I would talk with the owner. If it doesn't get through to them, then if I saw it in the woods screwing up my hunts, the third time I see itI would cap it, collar or not. After a day or so they'll we wondering where their dog is. That will teach them to let their dog run like that. Like they say, third times a charm. Whatever you do, don't go running your mouth about it afterwards because that's all you need....

Not exactly the nicest way of handling it but sometimes you need to grab the bull by the horns when enough is enough. Granted I have dogs and I am a bit of a dog lover, but that doesn't mean I won't shoot one (someone else's) if their owner is dumb enough to let roam after being warned twice.