Enflurane anesthesia in the pony: a comparative study between enflurane and halothane

Enflurane, a new volatile anesthetic agent, was compared with halothane as components of a commonly used clinical anesthetic regime in the pony. Enflurane provides satisfactory general anesthesia when administered at a maintenance concentration of approximately 1.5-2.5%, in combination with a 1:1 nitrous oxide-oxygen mixture. With both agents cardiac rhythm and pulse were stable, however significant arterial hypotension occurred, especially during and following induction, being anesthetic concentration dependent. Hypoventilation was induced by both agents, there being no significant quantitative difference in respiratory depression despite significantly lower respiratory rates with enflurane. Serum electrolytes and liver enzymes did not change significantly with either regime. Emergence from anesthesia was smooth, and significantly more rapid with enflurance. Post-anesthetic complications were not observed with either agent.