The histopathogenesis of the nephrosis-nephritis syndrome.

Chickens were infected with the Australian T-strain of infectious bronchitis virus. Histologically the disease started as a mild tracheo-bronchitis, accompanied by severe degenerative changes of the renal epithelia and marked inflammatory changes in the intertubular interstitium of renal cortex and medulla and in the propria and submucosa of the ureters and the main collecting ducts. There was a good correlation between the sequence of clinical signs and pathophysiological changes of the disease described by other authors and the sequence and extent of microscopic lesions in the renal tissues found in the present study.