Effect of acepromazine and butorphanol on isoflurane minimum alveolar concentration in goats

Thomas J. Doherty
Barton W. Rohrbach Dr., University of Tennessee - Knoxville
Dennis R. Geiser

Abstract

It was hypothesized that acepromazine and butorphanol would reduce the isoflurane minimum alveolar concentration (MAC) in goats when compared with a saline treatment. Following baseline isoflurane MAC determination in six healthy adult goats, the animals were randomly assigned to receive one of six treatments: intravenous administration of acepromazine at 0.025, 0.05 or 0.1 mg/kg; i.v. administration of butorphanol at 0.05 or 0.1 mg/kg; and i.v. administration of saline. Results show that isoflurane MAC in goats decreased between 36 and 45%, following the i.v. administration of acepromazine. Also, the results indicate that the use of acepromazine as a premedication in goats should allow a significant decrease in the concentration of isoflurane required to maintain general anaesthesia. Given that there are no significant dose response effect for acepromazine on isoflurane MAC, there would be no advantage in using higher doses of acepromazine. Butorphanol did not significantly change the isoflurane MAC in goats. Its effects, at the dosages studied, were variable and unpredictable.