Abstract
The cardiovascular effects of lateral and dorsal recumbency, and the usefulness of dobutamine infusion in dorsal recumbency in halothane-oxygen-anesthetized normal horses were determined. In dorsal recumbency, horses showed signif cant depression of cardiovascular function including decreased mean arterial blood pressure (less than 60 mmHg), decreased cardiac output (40% of the pre-anesthetic value), and decreased urinary output (less than 1.0 ml/kg/hr) . After infusion of dobutamine at a mean dose of 1.22±0.34 μg/kg/min into dorsal recumbent anesthetized horses, the blood pressure and cardiac output increased to over 70 mmHg and 60% of the pre-anesthetic value, respectively. An intravenous infusion of dobutamine was therefore an effective treatment for cardiovascular depression in horses anesthetized with halothane.
