I noticed that my RIR Rose was losing feathers a couple of weeks ago, and chalked it up to a late molting, but she has also had poopy butt for a couple of days now too, so I picked her up to giver her a once over and found that her skin is red and irritated on her belly and her "molting" doesn't seem so much like molting now, but rather a parasite of some sort. There were a few days where she didn't want to forage as much as everyone else, but she's snapped out of that and is otherwise fine and laying almost daily. Can anyone tell me what this is? I've also noticed that my 2 Wyandottes have strange things happening with the back end of their feathers as well. I've attached pix of my RIR as well as one of my Wyandottes (the last pic). As you can see, the Wyandottes look as though the feathers are broken off and it's quite downy. I thought that this might be how the breed looks in Winter, but with what is happening with my RIR, I wonder if it's something more. I also have a Red Star (ISA Brown) that seems perfectly fine and unscathed. What is this, and what can I do? I keep my coop VERY clean, use DE, and can't think of how I could better care for my flock! Please advise?!