monensin and Ataxia

Gelded horses of mixed breeding, ranging in weight between 360 and 455 kg, were fed pellets that contained monensin at concentrations of 279, 124, 31, and 0 ppm. Of 2 horses fed 279 ppm (253 g/T), both died. Of 3 horses fed 125 ppm (113 g/T), 1 died; feed intake was reduced in the 2 survivors. Of 3 horses fed 31 ppm (28 g/T), 1 had a transitory reduction in feed intake and the other 2 remained clinically normal. The 2 horses fed 0 ppm remained clinically normal. Monensin was also given to horses by gavage, at dosages of 1, 2, 3, 4, or 20 mg/kg of body weight. The LD50 was estimated to be between 2 and 3 mg/kg of body weight. The signs of toxicosis were partial to complete anorexia, ataxia, and intermittent profuse sweating.

Topics: Animals; Ataxia; Furans; Horse Diseases; Horses; Male; Monensin