I'll try to make this as short and informative as possible. My main flock is 3 roosters and 15 hens. Not the perfect ratio I know. Everyone gets along great!!! They are from 1 year to 4 years old. All healthy. I breed my leghorns and hatched out 40 chicks that are 10 weeks now, or whats left of them. I screwed up and build them a cage with a dirt floor in the corner of my barn and they have been getting sick. Coryza I'm pretty sure, they stink. I had culled alot of them sadly. I have called my county extention office to only receive a run around. I'm working on Getting in contact with someone willing to help at UK. Just to make sure what I'm dealing with. I've reasearched this to death. I found this medicine called: DI-METHOX sulfadimethoxine. It says it is specifically for coccidiosis, fowl cholera and infectious coryza. I'm 99% sure it is coryza. It also says NOT to give to birds over 16 weeks old. If my main flock hasn't gotten it yet does it mean thay are safe? This has been going on for over 5 weeks now. They have been raised close together. Is it safe to give to ALL the younger birds, even the ones NOT showing symptoms? They have all been together. Could the drug be used as a preventitive for the older group? I'm just at a loss. I bought some Oxine and I have been misting everyone with that. Plus I have 63 mail order 6 week olds in the front part of the property living out of a horse trailer. Or should I just cut my losses and just cull out the rest of that group, whether they look sick or not? I never knew raising chickens would be so hard. I'm trying real hard to keep everything clean. Thanks for reading.