Red Fox have “dainty” footprints in a straight line. The front footprint is wide compared to the more pointed hind paw. If snow is shallow or firm the prints will only show portions of toes and heel pads. Your photo looks as if these are not fresh prints. Did you notice a musky, skunky odor in the vicinity? Red Fox urine has an odor similar to skunk. I’d guess it’s a red or possibly gray fox. But tracking is tricky, and identifying tracks from a photo is even more so.BTW I get my information from a tracking class I took at North Branch Nature Center as well as from Peterson’s Animal Tracks Field Guide. Both great resources you should check out!