Please help. I feel so desperate. I don't know what my chickens have, but I'm loosing about 1 chicken every other day now. They start by getting a bit mopy and don't eat so much. The first sign seems to be that their crop isn't full in the evenings. This lasts for anywhere between a day to a few weeks before the next symptom which is balance loss. They fall forward onto their back and/or use their wings to keep their balance when standing. This lasts a day or two tops, before they start doing a funny neck twisty-jerky-thing. Yellow poop (like scrambled egg yolk) and death follow within 6 to 12 hours. It effects both hens and cocks. There is a possibility that there is a breathing problem as well as some of the hens have a very slight wheeze prior to getting ill. There is no poop change until right at the end of life. Sudden changes in temp, especially hot days, seems to make them much worse. Both flocks (it's spread to the other flock now) have had their shots at the hatchery. One flock is a little over a year old, the other 2+ years. I've tried antibiotics with no effect. Chicken-vit (or whatever it's called) has helped slow the progression of the illness, but they relapse after a few days. Please help! Any suggestions as to what they might have? I can't find anything like this in the books. Can I do anything to save the rest of the flocks? Edit: I wanted to mention that right from early on, they show the whites of their eyes and seem to have perception issues. They peck at something, but miss it entirely, often pecking above the ground and wondering why they didn't get it. Edit: Here's a more concise symptom list. Stage one, -tiredness, hunched down, disinclination to stand up, refusing food, dull feathers. Slight wheezing sound, and about half the time, some sneezing. Beak smacking. stage two - After a day or two, poor vision, poor balance, often using wings to stand upright. continued weight loss. More beak smacking stage three -Anywhere from an hour to two weeks later, they start jerking their heads and twisting their necks and they have yellow poop (scrambled egg yolk like). Death follows very quickly after this begins (12 hours at the latest).