Well,

I'm guessing your hand is approximately 7 inches from the tip of your middle fingerto the base of your palm (average caucasian male). That makes that front track ~3.5 inches. Definitely a dog, not only by shape, but also by pattern (hind is smalleri and inside the front).

Could easily be a coyote, especially a female carrying an extra 40 pounds of pups, because that track appears sunken quite deep.

For a quick link to mammal tracks:

http://www.bear-tracker.com/mammals.html