Heliotrine poisoning of broiler chickens: an experimental clinicopathologic study of low dose intoxication

Poisoning of 7-day-old broiler chickens with a low dose of heliotrine (10 mg/kg/day for 3 days) produced retarded rate of growth in male and female birds for a period of 14 to 21 days. Liver lesions in the majority of birds were not apparent grossly and were minimal microscopically. There was no biochemical evidence of hepatic dysfunction. Microscopic lesions consisted of slight swelling of hepatocytes and enlargement of hepatocyte nuclei and occasional haemorrhage. Ultrastructural examination revealed hepatic perisinusoidal fibrosis for a period of 4 to 21 days in association with minimal morphological hepatocyte change. Some birds developed ascites and more obvious liver lesions but degeneration, necrosis or megalocytosis of hepatocytes was not a feature. It was concluded that retardation of growth rate was not due to hepatic dysfunction.