My RIR has started losing back feather in March of this year. The chickens are just turning a year so I thought she was molting. But they every time the feathers grow her back is bloody sometimes, feathers missing and some on her wings broken. I have treated the coop for mites but no other birds are affected. This hen does not sleep on the roost with the rest of them and 80% of the time when the others are out in the yard she is sitting on the nest. I make her get off the nest and she will just go back into the coop. Lately I noticed some white poo on her but feathers but they have been eating from my apple trees. I have 5 hens total ( 2 RIR, 1 EE, 2 PBR) and 1 Amercuana Rooster. I got them as babies last April. Any advice would be great! Should I get rid of my rooster? Is there any treatments I can do? Her back is sometimes normal but other times really red (probably from mating).