POLIOENCEPHALOMALACIA INDUCED WITH AMPROLIUM IN BUFFALO CALVES - CLINICOPATHOLOGICAL FINDINGS

Polioencephalomalacia was induced in eight buffalo calves, 6-12 months old, by drenching amprolium (300 mg/kg body weight per day) for 29-55 days. Four buffalo calves of the same age group were drenched with ta p water only and served as control. Blood samples were collected at di fferent intervals during amprolium administration until the onset of c linical signs. Cerebrospinal fluid was also collected prior to amproli um administration and at the onset of clinical signs. A significant pr ogressive decrease in erythrocyte transketolase (TK) activity and an i ncrease in the percent of thiamine pyrophosphate (TPP) effect were obs erved in amprolium-fed calves during amprolium administration until th e onset of clinical signs. There was a significant increase in blood l actate and blood pyruvate concentrations and a significant decrease in lactate/pyruvate ratio at the onset of clinical signs. Serum electrol yte (Na, Ca, P, Mg) concentrations showed no significant changes. Howe ver, the serum potassium concentration had decreased significantly at the onset of signs. The cerebrospinal fluid analyses revealed a signif icant increase in lactate and pyruvate concentrations and lactate/pyru vate ratio in amprolium fed calves. The electrolytes (Na, K, Ca, P and Mg) of cerebrospinal fluid did not show any change. It is concluded t hat oral administration of amprolium (300 mg/kg body weight daily) for 4-6 weeks produces biochemical changes characteristic of polioencepha lomalacia in buffalo calves.