I am rather new to poultry keeping. I am raising Bresse and Legbars. I just moved a group of chicks out to my new outdoor brooder. I forgot the one rule I knew about chicken keeping...ventilation. I put heat lamps in the brooder and covered it completely with a tarp. Bad! Now two weeks later I have what I thought originally was Coccidiosis, then noticed respiratory wheezing and coughs and sneezes w/ gape mouthed breathing. I have culled three birds and against my better judgment started dosing water with Tetracycline and provided ventilation. That was the brooder and I have so far culled 4 of the most far gone chicks. I was thinking it was brooder pneumonia. Now one of my last adult Bresse Hens started having drainage from her sinuses and is wheezing. I immediately quarantined her. I had just moved 10 chicks to the coop about 4 days before she showed these symptoms. She is off her feed and water. Should I cull? Treat with ABX? I'm debating taking her to the Vet. Probably will. It kills me to cull her as my only other Bresse Hens were killed by raccoons. I was thinking Coryza and am dreading the possibility. If it is Coryza I have about 75 chicks in indoor brooders. When can I move them out and do I need to cull my whole outdoor flock?