EVALUATION OF XYLAZINE AND KETAMINE HYDROCHLORIDE FOR ANESTHESIA IN HORSES

  • 1 January 1977
    • journal article
    • research article
    • Vol. 38  (2) , 195-201
Abstract
The cardiopulmonary effects resulting from the combination of xylazine and ketamine hydrochloride were evaluated in the adult horse. Xylazine (1.1 mg/kg) administered i.v. prior to or simultaneously with ketamine hydrochloride (2.2 mg/kg, i.v.) provided excellent analgesia and light anesthesia in all horses. Cardiac output, arterial blood pressure pulmonary arterial pressure, central venous pressure and pulmonary arterial wedge pressure remained within normal limits for the adult horse. Evidence of respiratory acidosis developed with time during the anesthetic period. Induction and recovery from anesthesia appeared smooth and excitement-free. In the horse, larger dosages of ketamine hydrochloride (6.6 mg/kg) following sedation with xylazine (1.1 mg/kg; i.v.) were accompanied by muscular tremor and rigidity, mydriasis, oculogyric movements, sweating, hypertension, tachycardia and increased rectal temperature during recovery from anesthesia. Providing there was good sedation from xylazine, the combination of xylazine and ketamine hydrochloride as a short-term i.v. anesthetic technique in the horse appeared safe and acceptable providing reasonably stable cardiopulmonary function. If the sedative properties of xylazine are not apparent or if excessive dosages of ketamine hydrochloride are used, the drug combination results in serious side effects precluding its use for anesthesia in the horse.