My kids all have chickens as pets and we recently moved them into their winter housing as it is getting colder (10 c here) and has been raining for the last 4 days. We have 3 pens in close proximity to each other. Our oldest chickens (barred rock and easter egger) sound like they have colds. They started molting 3 weeks ago and we haven't had any eggs since. The easter egger appeared to be getting better but the barred rock is getting worse and is completely bald on its back, one eye is swollen shut and it is sneezing/gurgling and clearing its throat. These 2 share a pen. Last night, I found our little bantam game hen dead on the floor of her pen. I have since put tetracycline in everyone's water and culled the barred rock. The pens have all been disinfected with bleach. Anyone know what I am trying to fight here and is it a lost cause? Am I likely to lose the rest of them? We have a rhode island pullet and blue cochin (neither laying yet) and 4 ameracauna chicks (7 weeks old). Help please!