Abstract
The prevalence of hydropericardium syndrome (HPS) was studied in broilers of 3-5 weeks age from 10· poultry farms around Faisa labad. The source of feed and managemental conditions did not influence the course of severity of the ~_ disease. The liver suspension prepared from field cases of HPS, when inoculated in 10 days old, 20 embryonating eggs caused 100% stunted growth and mortality. In day-old broiler chicks, immunosuppression was achieved by application of colchicine for four consecutive days to the bursa of Fabricius on the cloacal lips. The colchicine treated chicks when challenged with liver suspension of HPS cases showed 90% mortality as against 10% in untreated chicks and zero per cent in untreated unchallenged chicks. Increased mortality was related to immunosuppression caused by colchicine. making the chicks more vulnerable to the causal agent of HPS. The pathological lesions in dead chicks showed distension of pericardial sacs with fluid. The hearts were flabby and showed haemorrhages on the epicardium. Microscopically. there were degenerative changes in the myocardial fibres along with cellular infiltration. Grossly, the livers were enlarged. swollen and mottled in appearance. Histologically there was massive necrosis. dilatation of sinusoid and presence of. basophilic intranuclear inclusion bodies in the hepatocytes. The kidneys were pale in colour and swollen which under microscope showed degenerative changes in 'the epithelial cells of tubules. Deposits of urates were encountered in the ureters. Key words: broiler chicks, colchicine, hydropericardium, immunosuppression
