Twenty-one free-ranging warthogs (Phacochoerus africanus) in the Kruger National Park, South Africa, were immobilized with a combination of medetomidine (0.07 ± 0.01 mg/kg), butorphanol (0.26 ± 0.04 mg/kg), tiletamine-zolazepam (0.69 ± 0.15 mg/kg), and ketamine (1.43 ± 0.21 mg/kg) administered intramuscularly by dart. Induction, immobilization, and recovery characteristics were evaluated using a standardized scoring system. In the immobilized warthogs, physiological variables were measured every 5 min and arterial blood gases were analyzed at 15-min intervals. At 45 min after initial drug administration, atipamezole (0.34 ± 0.050 mg/kg) and naltrexone (0.53 ± 0.079 mg/kg) were administered intravenously. Overall, induction quality after darting was scored as excellent and the mean time to safe handling was 5.9 ± 2.0 min. Based on muscle relaxation, and loss of palpebral and pedal reflexes, most subjects (17 out of 21) reached a plane of surgical anesthesia by 10 and 15 min; 20 out of 21 warthogs were in this plane for the duration of the monitoring period. In the immobilized warthogs the overall mean heart rate was 65 ± 15.3 beats per minute, mean respiratory rate was 14.7 ± 5.6 breaths per minute, and the mean rectal temperature was 37.9 ± 1.4°C during the 40 min. Arterial blood gas results showed hypoxemia (mean PaO2 62.1 ± 16.2 mmHg), hypercapnia (mean PaCO2 47.1 ± 5.1 mmHg), and acidemia (mean pH = 7.36 ± 0.04). Values for PaO2 and pH improved over the immobilization period. After antagonist administration, overall recovery quality from immobilization was scored as good, with animals standing at a mean time of 7.3 ± 4.9 min. The drug combination proved to be effective in the immobilization of free-ranging warthogs with rapid induction, good anesthesia, and limited cardiorespiratory changes. This anesthetic protocol produces effective, safe, and partially reversible immobilization in warthogs.
Keywords: Butorphanol; Phacochoerus africanus; ketamine; medetomidine; tiletamine–zolazepam; warthog.