Cardiorespiratory and anesthetic effects produced by the combination of butorphanol,medetomidine and alfaxalone administered intramuscularly in Beagle dogs

This study evaluated anesthesia quality, degree of analgesia and cardiorespiratoryparameters after intramuscular (IM) injection of a combination of butorphanol (0.1 mg/kg),medetomidine (10 µg/kg) and alfaxalone (1.5 mg/kg) in ten healthy adultBeagle dogs. Rectal temperature (T), heart rate (HR), respiratory rate(f_R), arterial pressure, arterial blood gases and M-modeechocardiographic left ventricular (LV) indices were measured before drug administrationand every 10 min thereafter until extubation. Mean duration of anesthesia, recovery andanalgesia were 89 ± 17, 6 ± 1 and 80 ± 12 min. HR, f_R, partialpressure of arterial CO₂ and O₂, arterial pressure, and LVcontractility were significantly altered during anesthesia. IM administration of the drugcombination provided acceptable anesthesia, but produced substantial cardiorespiratorysuppression.