We came home on Sunday to find one of our hens lying under the coop. At first we thought she was already gone, but when we went to move her we noticed she was still breathing. We tried to find what the issue was and noticed that she had hardly any meat on her bones, but there was no visible injuries on her. She still had most of her feathers except for a few missing on her back from the rooster. She would not drink or eat and her eyes were blood shot. We tried to nurse her for a while, but she eventually stopped breathing. We have no idea what happened to her. There were no injuries and other than being very thin, we could not find anything visibly wrong with her. Anyone have any ideas what happened and how we can prevent it in the future?