Since everyone has it, I would bet that they have infectious bronchitis. It is very fast spreading, and the most common of respiratory diseases, but most chickens will recover from it fine after 3-5 weeks, unless they are very young. Chickens who have IB will be carriers for up to a year after recovery. I would advise you not to get more chickens or hatch babies for at least 13 months. You may want to get a chicken tested for IB through your vet or state vet. If you lose any, then getting a necropsy by the state vet would probably tell you what they have. Here is a link to your state vet if you are in the US, along with some info on IB: http://www.usaha.org/Portals/6/StateAnimalHealthOfficials.pdf
http://www.thepoultrysite.com/diseaseinfo/78/infectious-bronchitis-ib/
http://www.merckvetmanual.com/mvm/p...view_of_infectious_bronchitis_in_poultry.html
http://www.thepoultrysite.com/diseaseinfo/78/infectious-bronchitis-ib/
http://www.merckvetmanual.com/mvm/p...view_of_infectious_bronchitis_in_poultry.html
