The aim of this study was to investigate the effect of levomepromazine and atropine sulfate as a premedication to the dissociative anesthesia produced by a tiletamine/zolazepam combination. Ten dogs were randomly assigned to each of the three groups: control, atropine and levomepromazine. Fifteen minutes before tiletamine/zolazepam, the dogs were treated either with atropine sulfate (0.044mg/kg, subcutaneously) or levomepromazine (1.0mg/kg, intravenously), and the control group with saline (0.2ml/kg, intravenously). The tiletamine/zolazepam combination (10mg/kg) was administered intramuscularly to all dogs of the three groups. ECG, temperature, respiratory rate, tidal volume, minute volume, heart rate, arterial blood pressure, arterial blood-gases, degree of analgesia, skeletal muscle relaxation, ocular, pharyngeal and interdigital reflexes were measured before and 15 minutes after premedication and at 15, 30, 60 and 105 minutes afier tiletamine/zolazepam administration. In addition. the amount of salivary secretion, duration of induction, surgical anesthesia and recovery, were also evaluated. The results suggested that atropine should not be used as premedication in combination with tiletamine/zolazepam due its synergic effect on the tachycardia. Levomepromazine reduced the amount of salivary flow, produced minimal changes in the cardiorespiratory variables and potentiated the anesthesia with tiletamine/zolazepam.
anesthesia; dogs; tiletamine; levomepromazine; atropine
