Clinical Comparison of Medetomidine with Isoflurane or Sevoflurane for Anesthesia in Horses

The effects of anesthesia using medetomidine combined with isoflurane or sevoflurane on hemodynamic parameters, blood biochemistry, and intraocular pressure was evaluated in horses. Healthy horses (n=12) with a mean body weight of 438±51kg were used. Premedication was provided by administering medetomidine (7 µg/kg) intravenously (IV), and general anesthesia was induced by administering ketamine (2.2 mg/kg) and midazolam (0.03 mg/kg) IV after which isoflurane (n=6) or sevoflurane (n=6) was administered for inhalation anesthesia. Blood gases, respiratory rate, heart rate, electrocardiogram, body temperature, and oxygen saturation, as well as systolic, diastolic, and mean arterial blood pressure were recorded at 0, 5, 15, 30, and 60 min after administering medetomidine. Statistically non-significant differences in the study variables were observed between the isoflurane and sevoflurane groups. Blood gases and electrolyte parameters in both groups were unchanged. Intraocular pressure and liver enzymes levels were similar to reference values. Anesthesia protocols of study using medetomidine combined with isoflurane or sevoflurane produced minimal complications in horses. Medetomidine with sevoflurane provided deep anesthesia, and had fewer cardiopulmonary effects than medetomidine with isoflurane.