It's been a bad day for my rooster. First I clipped one of his claws too short and had to stop the bleeding. I'm keeping him sequestered in spare cage in my rabbit hutch for a couple of days to keep him quiet until he heals. He's not very "handleable" so I don't examine him often. As I put him in the cage today, I noticed that under his tail he has a few feathers missing and the skin on his rump is bright red and looks irritated. He also seems to feel a bit of pain when touched. He's not dirty back there from feces, although he is a bit muddy because the run is wet. At night he sleeps on a 2x4 roost about 4ft above ground. Plenty of space, so I can't imaging that it would be from close quarters.
Could this be mites? Are mites a winter problem? I would take a photo, but I can't get him to hold still during the daytime.