I was out checking the chickens this morning when I noticed that one of my 8-week-old cochins was hiding a bald spot around her shoulder. I picked her up and, to my surprise, found what looks like a MASSIVE blister. The skin feels thin, there are only a few pin feathers on it, and veins are visible. An extreme close-up: Any idea on what I should do about this? Do I just leave it? Drain it?