Pathological and Biochemical Effects of Intramuscular Gentamicin Administration in Chickens

The objective of this experimental study was to examine the pathological effects of the intramuscular administration of gentamicin to growing chickens. Two experiments of 35 days’ duration were conducted simultaneously. In both experiments White Leghorn cockerels of 6 weeks of age were randomly divided into 4 groups and gentamicin was administered intramuscularly to the birds on days 1 and 3 at a dose of 10, 50, 100, and 0 mg/kg body weight, respectively. Birds administered 50 and 100 mg/kg gentamicin showed depression, diarrhea, increased water intake, and lower body weights. Mortality was 0%, 26%, and 100% in the 10, 50, and 100 mg/kg gentamicin groups, respectively. Kidneys and livers of the 50 and 100 mg/kg groups were swollen, friable, and hemorrhagic. Microscopically acute tubular necrosis was observed in the kidneys and fatty change of hepatocytes in the liver. Gentamicin administration resulted in a significant decrease in serum albumin and a significant increase in urea nitrogen and creatinine concentrations.