I vote for dog with the deep barrel and wimpy tail. My husband votes for Old Pointy Nose because of the slender legs. Neither of us vote for fox.
What do the tracks look like? If the toes are more rounded, and the pad tracks are fairly small , it's a fox. If the pads are very, very different from front and back, and the toes are elongated, it's Old Pointy Nose. Front feet are larger than back on Old Pointy Nose and the toes on the outside are usually larger than the inside - this and the pad difference can help you see the difference between Old Pointy Nose and a domestic dog. If you come across jumps of six to ten feet, it's definitely Old Pointy Nose. If there are scratch marks around the scat, it's likely not a fox, although seeing a lot of fur in the scat is more likely fox of some sort in my personal opinion. If the tracks are in a 2x2 trot pattern (same foot in front in each pair of legs) it's probably Old Pointy Nose since they trot sideways a lot. Foxes will sometimes sideways trot; but they walk more than Old Point Nose who usually trots or lopes. Pointy trot strides are about a meter long (39"), red fox is next longest at about 32'. If it looks like domestic cat tracks, it is probably a kit fox.
Old Pointy Nose tracks and red fox tracks usually show claws; gray fox and kit fox frequently don't leave claw marks, in fact claw tracks are very rare with gray fox. Stride length is different, too.
The side ways trot pattern would look sort of like this:
X
X
X
X
not to be confused with a lope, which is like this:
X
X
X
X
Canids have a rotary lope, while equines have a lateral lope. The above is a rotary lope.
I hope you're not as confused as I am.