Looks canine to me, dog. It helps to put a tape measure in with the picture to gauge size. A fox prints are small enough to look the size of a domestic cat, but you can see the nails/claws with a canine.
Might be a coyote, the splaying of the track could be due to the depth of the snow. I think a dog track would of had the two middle pads spread a little more apart. But, then I'm not much of a tracker
A canine for sure - you can see the claws in the prints (a feline would have them retracted, thus no claws in the print). Based on them being 2 1/2 inches long, I would guess either coyote or domesticated dog.