Longtime lurker, first time poster... I started with a batch of 25 standard sized mutt chicks last spring and have added several different batches of various types of bantam/standard chickens. I also added 10 guinea chicks mid-summer. I have 2 ducks that live on the pond, but occassionally visit the chickens for food and company. What I'm about to describe has happened mostly to the first batch of 25 chicks, but also most recently to a later addition, and earlier to a guinea. I've had about 8 cases total. I have a 6x9 coop with sawdust floor, an attached 5x16 fully enclosed run, and a larger maybe 20x60 fenced area that I open to them from dawn to dusk, and frequently (2-3 days/week) let them out to free range. They have a constant supply of layer mash and a single large waterer that only occassionally runs dry before I get it filled (it's never empty for more than 12 hours at a time, at most). Both are located in the coop. I feed them table scraps when I have them, and scratch as a treat. Now, I think that takes care of the background, now on to the symptoms. I find the chicken on the floor of the coop, laying on its side. They always seem alert and not in pain or distress. They don't appear to have any outward physical injuries (like from pecking or a predator). It's almost like a partial paralysis. They can kick and flap their wings, but very uncoordinated. They can't stand or fly. I have let them lay there for about 24 hours, with no idea what to do. Eventually they weaken, as I don't think they can feed or drink, and I put them down. This has occurred as close together as a couple days and as far apart as 8-10 weeks. If it was a disease I would expect it to move through the coop and take out a bunch at a time, not lay dormant for long periods of time and only affect a single chicken at a time. It's happened to both hens (laying and not) and roosters and 1 guinea. In some cases, I've noticed the chickens acting differently as much as a week or two before hand. Staying off by themselves, seeming to lack energy, etc. Other times, it happens out of the blue. I just don't get it. Any ideas or questions?