My DH and I are a bit puzzled and couldn't find much of anything of substance regarding Eimeria in adult chickens, so here's the story: We have five hens (all 1.5 years old) and one roo (1 year old). In the spring and fall we take a composite fecal sample (one from each bird, because if one's got something, they all do or soon will) to our vet for analysis for intestinal parasites. This fall was the third time we've taken a sample in and the first time we got anything but a perfectly clean bill of health. This round, Eimeria oocysts were identified (they could not determine species) in "low numbers". I can find tons of information regarding chicks, but can't find hardly anything with regards to adult birds, except the Merck manual: http://www.merckvetmanual.com/mvm/index.jsp?cfile=htm/bc/200800.htm. They're all asymptomatic and are eating, drinking, and pooping perfectly normally. Two just got done molting and have started laying again, a third hasn't molted yet and continues to lay, and the rest are in the middle of molting; otherwise no laying interruptions. They just got their monthly lice/mite check and were clean. The coop and run are sheltered from wind/rain 24/7 and only a small portion of the run ever gets damp when it rains, and it's sand and doesn't stay wet more than 24 hours after it stops raining anyway. The coop is cleaned out weekly and the run is raked out by-weekly. Anybody have any experience with this and what treatment did you use (if any)? I know there are some risks of poisoning with sulfa drugs, though Amprolium supposedly works in adults as well as chicks? Supposedly they're immune if they survive infection...but may shed oocysts? Or not...depending on snippets of info I see about chicks and don't know how it applies to adults. So yeah, any clarification(s) someone may have would be great.