I have a 3 year-old Barred Plymouth Rock who has only recently begun to show odd symptoms. When I went out to visit them this morning, she appeared normal. When I went out again tonight, I found her unable to stand up, heavily breathing, tired, and her comb had a purple tinge to it. She has been laying about 2-3 eggs a week. There have been no changes in environment, diet, or stress factors. Her weight has not changed, though she has no desire for food or water currently. My questions are: What does she likely have and how can I treat it? She is currently separated from the rest of the flock. Also, she shows symptoms like those of one of my chickens who hit her head hard, so is that a possible diagnosis? Thank you in advance for any help.