I reviewed the Learning Center pages on Chicken Illness but it is tough to sort through and I would appreciate some advice. Went to let the girls out of the coop this morning and once the water was filled I realized I was one hen short. She did not rush out for breakfast with the others and when I went back in the pen she was on the floor of the coop with labored breathing and legs sprawled, like she couldn't support her weight. I scooped her up and she is very lethargic and seems to be in and out of consciousness or is having trouble staying awake. When I put her down to get a box ready she practically tipped over on the ground. There is no sign of illness or injury in any of the other chickens. She has always been the runt of the flock, so I am hoping this is just her genetics catching up to her, I am worried though that her size just means she is the first to show signs. Any tips to keep my other girls healthy Thanks so much.