A Sorry Sight

Normally the foxes use the garden as a walk through, to get from A to B. I sometimes see them come through at around sunset. They are pretty sharpish and soon disappear into next door's garden. This fox appeared at lunchtime and was walking so slowing and pausing so long, that I had a chance to get a photo. He was a very sorry sight though, with mange, a completely bald tail and very little coat remaining on his hind quarters. I'm going to take advice to see if I can help, but I don't know where the foxes sleep or hang out, so it might be difficult.