The following was created to be used as a reference. Please do not use my actual images! This is a single loop of the run cycle of a fox, in this case, I made a cross fox, which is one of my favorite variations of the red fox.
The run cycle in the image goes from the top to the bottom. This is a more passive or casual run, where the feet are all off the ground for a very short period when the back legs cross the front legs. In a galloping run, which I plan to create at some point, the feet are all off the ground twice. The first time is when their legs cross (back and front) and the second is when the legs are the furthest from each other. Basically, during the condense and extended portions of the run cycle.