We have a chicken who was always being pecked at by another flock member. So her wings were always a little feather-less. She is a Gold Sex Link. A few days ago, however, we saw that her left wing was drooped down. And she was shedding her feathers. Now she never comes out of her coop, and stays in there all day. We go into the coop and feed her, but we have not tried any remedies yet. Please help.