I am so sad about all these "sick birds from auction" stories. My personal solution is to cull them. These diseases, most of them with that symptom, will make them carriers for their lifetime, meaning they can infect your entire flock, even if they seem to recover. This is why I refuse to ever buy birds from anyone. You set up a cycle of disease in your flock and weaken the entire flock. You will always be treating stuff if you allow them in the flock, IMO. I"m sorry someone sold you sick birds. Remember, many diseases chickens get are herpes type viruses and you know that is permanent.