i have several chickens that have developed respitory symptoms right now. Last year I vacinnated my hatch for Newcastle-bronchitis and in doing so many of them developed symptoms and died. They shared that with my existing flock and I am still dealing with it. Periodically they get the runny nose and sneezing thing but aren't dying anymore. I usually treat with Tylan for 7-10 days until its better. But now, I am thinking about culling them as their symptoms ocurr. I am curious--will I ever get ahead of this...or will all my chickens develope this? I have another hatch this spring, and I am afraid of what is going to happen. I plan on cleaning the coop and disinfecting it with white vinegar--but whats the reality of "really" disinfecting anything? it is a wood floor coop, the other one is dirt floor....and of course, I have a large chicken run, probably 40x75 feet--can't disinfect that. Originally when I got my chickens it was for eggs. But with the second order, I was given a free Cornish Rooster who is big, and mean. I wanted to breed him with some Rocks and put them (and him) in freezer camp. But, I guess I can't or shouldnt put any of these birds in the freezer since some have had symptoms of respitory infection and all have been vaccinated and/or treated with antiobiotics? I am at a loss on what to do. I am not niave enough to think that the chicken we buy from the grocery store is not ever sick or exposed to things prior to its processing....but.... any advice?