I have a young Bantam rooster who I brought into the house when he was pecked severely by the others. While recuperating he developed a very severe case of mites which he must have had all along; however, while indoors he could not dust bathe. I treated the mite infestations with a drop of ivermectin applied in the vent area. He seems to be free of the mites but has yellow crusty scabs over most of his skin. What is this and how do I treat, please? I will be grateful to learn from your experience.