I have a NHR hen that has lost some feather's on her back right about her tail feather's. I haven't noticed any pecking going on in the pen. I have also trimmed my roo's spur's to make sure that is not what it is. I have checked for mites, clean there. They have all been wormed. The spot is not bleeding and is not raw, just bare. Any idea's what it is and what I should do. I am a very hands on person and I spend alote of time with my chickens and I can't seem to figure this one out.