I'm searching for answers to this same problem. I have a white leghorn Pullet who is now 10 months old and has never laid an egg. At about 7-8 months old she started to look like she was molting. Now at 10 months her feathers still look very ragged and I've never heard of a hen molting for almost 3 months! She is at the bottom of the pecking order but I've observed her treatment by the other members of the flock and haven't seen any birds pecking her. After all my research I can only assume she has parasites. I wonder if anyone can give me advice on how to treat a hen for parasites?