Cardiopulmonary and sedative effects of intramuscular medetomidine-ketamine and intravenous propofol in ostriches (Struthio camelus)

Eight captive ostriches (Struthio camelus), ranging in age from 9 to Il months, were given a combination of medetomidine and ketamine, administered intramuscularly, and propofol, administered intravenously, for induction and maintenance of anesthesia. Medetomidine (80 mu g/kg IM) and ketamine (2 mg/kg IM) resulted in profound sedation and sternal recumbency within a mean time of 14.6 +/- 10.0 minutes in 6 birds. Two birds remained standing but were moderately sedated. Propofol, used for induction (3 mg/kg IV) and maintenance (0.2 mg/kg/min constant rate infusion) of anesthesia, enabled intubation and provided muscle relaxation sufficient for restraint tasting 30 minutes. Apnea was observed after propofol administration, but spontaneous ventilation resumed within 60 to 90 seconds. All birds were bradycardic throughout the anesthetic event. Both the heart rate and the cloacal body temperature decreased significantly at 25 and 30 minutes, respectively, after induction. By 5 minutes after induction, the respiratory rate increased significantly and remained high throughout the remainder of the 30-minute evaluation period. During the anesthetic period, systolic, mean, and diastolic blood pressures, as well as arterial pH, arterial oxygen and carbon dioxide partial pressures, and end tidal carbon dioxide partial pressure showed no significant changes. The relative arterial oxygen saturation (SpO(2)) was significantly elevated at 15, 25, and 30 minutes after induction. The SpO(2) was less than 90% at 2, 5, 10, and 20 minutes after induction; however, arterial blood gas analysis indicated adequate arterial oxygenation. Anesthetic reversal with the alpha(2)-antagonist atipamezole (400 mu g/kg, one half IV and one half SC) was smooth and resulted in a mean recovery time of 21.0 +/- 7.3 minutes. The combination of IM medetomidine-ketamine and IV propofol used in this study proved to be effective for sedation as well as the induction and maintenance of anesthesia in captive ostriches.