My chickens were attacked by my dog yesterday. Two of them are still alive, but one is very badly injured. She has a 3" patch of skin and feathers torn off her back as well as a chunk taken out of her muscle. It got down around zero degrees last night so I think the wound froze too. They made it through the night and she is eating and drinking inside the coop. The other one doesn't have any noticeable wounds but is laying down and sleeping. Can a chicken recover from a wound like this? How can I treat this large open wound?