Domestic canine tracks overlap >.50" with the front paw tracks, wild coyotes and wolves, as well as fox tracks will more often than not step directly in the front paw track.
We used to have wild coy dogs in our local area many years ago, some weighing up to 65 pounds and could drag down a full size deer under the right conditions. They also hunted in packs and more active at night. Their tracks overlap, same as domesticated dogs, but combined with looking, listening, and speaking to others in the area, it should not be hard to find the the source
Many times it will take more than one example to tell a domestic dog from a wild one, they can be difficult to tell at first, but study the signs, check scat, look for more than one track in the area, and spend some time out in the area at night and listen. The olny one I would not trust after dark in the lower 48 would be the coydog. I have been approached by one in the late 70's, and to this day I believe if there had not have been two of us together that night, I would have had a real time. He approached within 8', and snarling, I could see the whites of his teeth as he apprached at a fast trot, then he verred off at the last minute and he was gone. It was a cold december night and we had heard them off and on running deer at night within a half mile of where that took place., they pack up pretty tight, and their tracks often are overlapped with others in the pack.