From what I can tell it is from my rooster. She is new to the flock I didn't notice this at first because she was pretty plucked anyway.. but now it is black.. She is eating ok .. I did a saline wash on it and then a peroxide and water wash.. I am buying inject-able antibotics. It doesn't smell rotten but it sure looks it.. I have her in a carrier with hay in my laundry room..I boiled eggs for her ..Is there more I can do...I am very new