One of my chickens (who already can't walk very well due to the fact that she was attacked by a raccoon when she was a chick) is now sitting down most of the time. When she tries to walk she usually falls down and can only stand for short periods of time. She's also a bit shakey and her face and comb are an unusually bright red color. I noticed this early this morning. Can someone plz help and give me some advice on how to treat her?