This chicken has been lethargic and walking low to ground. Yesterday these sores were red and raw. I soaked her in an Epsom bath and isolated her for the night. Today she was out with the others. Still low walking but spunky when another tried to peck her. I bought some spray (starts with a V, I want to get this post up and I left bottle by coop). I am surprised by the color of her poo as I did not see any like this this morning. When spreading feathers for photo, something small and black scurried away. I looked and looked and could not find others. Mites? I see no other indication on others of mites and I could not see any more on her. Any ideas? And why yellow under skin?