RE: What left this track?
Domestic dog by the looks of it... a hint is that domestic dogs tend to have a more "circular" track as a whole withspreadout toes,and wild dogs tend to have "oval" tracks with tight toes, oftentimes being able to see fur between them. Also, wild dogs tend to have one track at a time, not two on top of eachother as the picture shows. Mud can have an affect on the toes, spreading, but by the looks of it, it's just a big domestic dog-- especially because coyotes don't have tracks that large--generally. Another good indicator for species is if the tracks run in a straight line, as they would for a coyote, or if they wander like a fox would. Hope this helps.