My speckled sussex has been developing sores on her feet. It started on the top of one of her toes, and every day she seems to have another. This morning when I opened the coop she was bleeding from a new sore on her leg. She is having more difficulty moving around as more sores appear. Is it possible that rats or mice are doing this? She roosts on top of the feed container, a galvanized garbage can with lid. I used hydrogen peroxide on her toes and legs today then applied some petroleum jelly. Should I continue this treatment or try something else?