I live in a rural neighborhood and was quite surprised to see an injured red fox in the field behind my house on Monday...walking on 3 legs with the 4th leg tucked under. It was still wandering in the field yesterday afternoon....Last night, there was another (healthy looking) fox in the same field and it was digging vigorously at the snow. The injured fox was nearby. Any advice on what can be done to help the injured fox (if anything) and if these foxes pose any threat to cats (I manage a feral cat colony)? THank you!

Nature will have to take its course. It will be harder for the fox to hunt with only 3 working legs. But it sounds like its mate is nearby. If the other fox was digging in the snow it was after a mouse or vole. As long as the pair stays together, and the leg injury doesn't involve an infection, the injured fox may do o.k. The foxes aren't likely to mess with the adult cats, but they may view them as competition for the local population of mice and other small rodents. Keep an eye out for the cats (particularly kittens). If you can, provide the cats with a secure indoor location where they can go at night. That way they have a safe place to escape from coyotes and possibly the foxes. And try not to feed the cats out in the open or at the least clean up any remaining food before dark. Foxes, coyotes, and other wildlife will be attracted to an easy meal of cat food. If the cats and the wild canines are both using that same location to find food, it's only a matter of time before they run into each other, which won't likely be a happy meeting for the cats.