We have two mini donks, Pete and Penny. Pete is gelded and Penny is a jennet. They are in the same fenced in area with a lean-to-shed. Started noticing this summer that they were both losing hair on top of their backs and down towards their rumps and right away thought they had been biting each other.

They still haven't grown back the hair but I don't see them biting each other, yet, at the same time they don't seem to itch or scratch on anything. Their diet is always the same, the only thing I can think of is maybe they are "sick" of each other so they bite each other or maybe they don't have enough room? I don't think it is mange, their skin isn't "oozy" or red....anyone have any ideas?