All of them are suffering of this to some degree. It's only on their backs under their wings. Guineas also have it. Ideas?? Part of me wonders if I burned them. The brooder I built had a seam I didn't staple enough and they were getting out. I had them in a large dog kennel for 2 days. I didn't keep the light on during the day just turned it on at night. It was pretty close to them but the kennel is really large so I thought they had plenty of room to get away from it. I just don't know.