hello my road island reds are having problems .two of my hens have molted so bad that now their backs are Bald.And it dose not seam to be growing back. But my third hen has a nasty balded spot on her bum, and its red and inflamed. they are about a year old .and it started just after the last frost we had hear. I live in upstate New York . she has stop laying and I am worried about them all. Is there some spray I can put on her . I have changed their bedding from hay to wood chips . they have Plenty of water.I have water stations all over the Yard .they free range and go back to the coop to eat and sleep . they have gotten in to sunflower seeds that I put out for the songbirds , but nothing else their poo looks normal .can the roster be doing something to them . I have 5 hens and 1 roster ,he is not showing any sines of anything and nether is my other two hens .should I separate them, this is my first tim having chickens , so any help would be welcomed. thank you . Charlene .