I have 4 adult chickens that I have had for over 3 years and never had a problem with their health. I got 4 new chicks this year and all of a sudden I have an outbreak of cocidiosis with them. I was wondering what could have caused this? We have trapped alot of opossums this year and a couple of raccoons but I don't think that would have changed anything. Any help would be greatly appreciated. All of the chickens are on medication.