I am a brand new backyard chicken "farmer" and recently went through a horrible event with two new chicks and in the course of my research, stumbled across BYC's article on Coccidiosis. I believe (but cannot confirm) that this is what plagued my two newest members and eventually caused their demise. One chicks illness was very slow to develop, and unfortunately never was accurately diagnosed. Our local veterinarian does not treat chickens and was not at all helpful, and sadly neither were our three Ag stores. In communicating with the breeders we purchased the chicks from, they originally believed this little chick was injured when introduced to our two older birds - her symptoms appeared neurologic in nature. But two weeks after her passing, the second chick, who up to this point was extremely healthy and thriving, took a sudden turn and passed away in less than two days. She was literally chasing the older two birds around the yard, stealing worms from them one evening, puffed up and extremely lethargic the following morning and day, and gone the next morning. Their stools were never bloody, but had become very loose and green in color. These were hatchery chicks, from a small farm that deals primarily with rare and endangered breeds, and the chicks had not yet been introduced to foraging, that I am aware of. Our older two chicks were hatched and raised by a friends hen, and began foraging right away. They are no showing any signs of illness, despite being in the same coop and constant close proximity to the youngsters. I am hoping they developed an immunity and will not become infected. We have a modest sized back yard and turned our chicks out to forage within a week of bringing them home. With no other logical reasons (having exhausted other possible environmental causes), I believe that this is what they both had/developed, which is consistent with all the research I have come across. My big concern, beyond educating myself on future prevention, is that we had pre-ordered two more chicks from the same farm, and they are due to be delivered tomorrow. They will be 12 weeks old. I have cleaned out the coop, but understand that the oocysts of coccidia live in the soil and are virtually impossible to eliminate. What should I do? I am absolutely terrified that I won't do the right thing and paranoid that these new chicks will become ill as well. Please help, ANY advice is greatly appreciated!!