Sedative Effects of Medetomidine, Detomidine, and Xylazine in Horses

Five each of Thoroughbred horses were given intravenously medetomidine (MED)(0.003, 0.005, and 0.01mg/kg), detomidine (DET)(0.01, 0.02, and 0.04mg/kg), xylazine (XY)(1mg/kg) or 5ml of saline. MED (0.01 mg/kg) produced the deepest sedation with most severe and prolonged ataxia. Sedation and ataxia by 0.04 mg/kg DET was similar in degree to those of 1mg/kg XY but more prolonged ataxia was produced as 0.01 mg/kg MED. Sedative effect with less ataxia was produced by 0.005mg/kg MED as 0.02mg/kg DET. Light sedation with short duration and no ataxia was produced by 0.003mg/kg MED.