I have done a lot of research trying figure out what my flock has and I am 95% sure that they have Infectious Bronchitis. All of their symptoms fit the descriptions that I've read about. Good news is that the mortality rate usually stays at about 5% and they won't remain carriers for life, just a few months. You can also vaccinate against this illness, which is good to know. The IB lasts for 7-14 days. It is VERY contagious and easily spreads with and incubation period of 18-48 hours. The incubation period even fits! Everyone might want to look into this vaccination. It can be sprayed on them, given orally, or given as eyedrops. I will definitely be vaccinating my flock for now on. Just FYI!