I have been loosing chickens for about the past 2 weeks, one at a time. 3 hens and now my beautiful Cochin Roo. Everyone seems fine, except the hens stopped laying about 3 weeks ago. Figured it was just moult. We introduced 5 pullets from a trusted source, kept them all quarantined and the introduced them. Thought that maybe there was some stress factored into the lack of eggs. When the first chicken died, we called her runt, always small and frail I just thought we were lucky to have her as long as we had. Then two more this weeked. No coughing, sneezing or difficulty breathing, just dead. Poo looks fine from everyone. The only thing is the roo acted like he was having trouble standing yeasterday evening. When I went out this AM it's as if he just fell over dead. Everyone is eating and drinking normally. None of the new birds are acting sick, just the birds from my original flock and as I said they don't act sick. Just die overnight. Please if there is anyone out there that might know what the problem is or what I can do please let me know. I do have some Duramycin, but I don't even know if they need an antibiotic.