In vivo evaluation of ziram induced acute toxicity on pathomorphology of broiler chicken

Abstract

Fungicides are usually used in agriculture and often find their way in poultry feed. Therefore, a study was undertaken to study the in vivo effect of one such fungicide (ziram) induced intoxication on pathomorphology of broiler chicken. After 2 weeks of age the birds were given fungicide (Ziram) in feed as a single oral dose of 100 mg/kg body weight. Out of 10 birds, 3 died due to ziram intoxication (30% mortality rate). Birds that died rapidly showed pronounced neurological signs like convulsions. The carcasses of ziram intoxicated birds appeared dehydrated and their mucous membrane was pale in colour. Marked vascular congestion was observed in brain on gross examination. The livers showed congestion and haemorrhages with necrotic foci. Kidneys and lungs had ecchymotic haemorrhages and heart revealed gelatinization of pericardium, distention and pericarditis. Atrophy of bursa of Fabricius and thymus; hypertrophy of thyroid was found. Histopathological examination revealed neuronal degeneration and necrosis associated with mild gliosis in brain. Lungs, pericardium and epicardium had severe congestion and there was degeneration with separation of myofibers. Glomeruli were congested and frequently revealed hypercellularity. There were sinusoidal congestion and varying degrees of hepatocellular degeneration. Bursa revealed mild depletion of lymphoid cells in few lobules while as thymus showed hypoplasia with depletion of lymphocytes. Thyroid had mild mononuclear cell infiltration and caecum showed marked necrosis and denudation of the mucosa. In conclusion, the depletion of lymphoid tissue from lymphoid organs was suggestive of immunosuppressive and immunomodulatory effects of ziram toxicity in broiler chicken.