Our lovely Casty is extremely ill. For the past week she has got gradually quiter and more withdrawn. Now she cannot stand up and leans to one side breathing heavily and slowly and eyes always closed. She is not eating or drinking although we are giving her natural yoghurt down her throat. She has been having loose and watery green stools. No sign of lice and we have wormed them recently. Neither of our other chickens in a similar state. Will do anything to save her. Very dear to us. Please Please help!