I noticed other hens pecking at the behind of my barred rock. She's lost all of the feathers and down around the vent, and the was some black scabby material around the vent. I isolated her for the last two days, and she layed an egg yesterday, and again today. Both eggs looked normal but were covered with blood and white puss/poop looking stuff. The skin of her abdomen is very red. I'm not sure if that is from the feather loss, or if she has some sort of infection in the abdomen. I washed her butt, and most of the scabby stuff peeled off, and the skin under it looks normal. She seems to be alert, and eating, and her poop looks normal. Any ideas about what's going on with her?