Pathomorphological changes in tissues of stunted chickens experimentally infected with avian reovirus

The present investigation was carried out on 40 (vaccinated against RD) broiler chickens of 1 week age (divided into Control and Reovirus infected groups of 20 chickens each) for a period of 20 days to study the gross and histopathological changes in avian reovirus infected chickens. The broiler chickens of group-B were infected orally with avian reovirus @1ml of 107 TCID50/bird, and of group-A were given 1ml normal saline solution. All the broiler chickens were kept under identical feeding and managemental conditions throughout the experimental study. Five birds from each group were humanely sacrificed at 5 days intervals for gross and histopathological examination. The gross pathological changes during necropsy of stunted birds included pasty vent, weakness, fibrosis of pancreas, enlargement of gall bladder, catarrhal enteritis and presence of undigested food material in the intestine. Hepatomegaly and discolouration of liver were also seen in a few cases. The histopathological examination of liver revealed degeneration and necrosis of hepatocytes along with mononuclear cell infiltration around the blood vessels. The distal part of large intestine showed necrosis and desquamation at the tips of villi with mononuclear cell infiltration in lamina propria. Microscopically, the pancreas revealed degenerative and necrotic changes along with fibrosis of the wall of the pancreatic duct. The bursa showed capsular fibrosis and lymphoid depletion in follicles. Proventriculus showed necrosis and mononuclear cell infiltration.