Diagnosis of infectious bronchitis in chickens

INFECTIOUS bronchitis is a common endemic respiratory viral disease of chickens, second only in importance to Newcastle disease and avian influenza. it is caused by an avian coronavirus and primarily results in respiratory diseases and loss of egg production, with some strains reportedly causing nephritis, proventriculitis and pectoral myopathy. it was first identified in 1935 and is still prevalent worldwide, continuing to challenge commercial, backyard and small-scale flocks and pet chickens. It is a difficult disease to diagnose, as clinical and pathological findings are not pathognomonic. Thus, careful field investigation, appropriate collection of samples from live birds and carcases, and an appreciation of laboratory protocols are vital for a conclusive diagnosis. This article describes the diagnostic approach to identifying infectious bronchitis in a flock.