Our duck has had a rough time lately. We treated her for bumblefoot, and she's recovering. Tonight we noticed she had some blood on her feathers. When we checked we found several sores about the size of a nickel or bigger on her skin. Some look like scabs, a couple look like gangrene. We have been giving her antibiotic shots for about 2 weeks and then she had 6 days of shots a week before that. Suggestions? I'll try to get a couple of pictures of it.