Reversible anaesthesia of free-ranging lions (Panthera leo) in Zimbabwe

Abstract

The combination of medetomidine-zolazepam-tiletamine with subsequent antagonism by atipamezole was evaluated for reversible anaesthesia of free-ranging lions (Panthera leo). Twenty-one anaesthetic events of 17 free-ranging lions (5 males and 12 females, body weight 105-211 kg) were studied in Zimbabwe. Medetomidine at 0.027-0.055 mg / kg (total dose 4-11 mg) and zolazepam-tiletamine at 0.38-1.32 mg / kg (total dose 50-275 mg) were administered i.m. by dart injection. The doses were gradually decreased to improve recovery. Respiratory and heart rates, rectal temperature and relative haemoglobin oxygen saturation (SpO2) were recorded every 15 min. Arterial blood samples were collected from 5 lions for analysis of blood gases and acid-base status. For anaesthetic reversal, atipamezole was administered i.m. at 2.5 or 5 times the medetomidine dose. Induction was smooth and all lions were anaesthetised with good muscle relaxation within 3.4-9.5 min after darting. The predictable working time was a minimum of 1 h and no additional drug doses were needed. Respiratory and heart rates and SpO2 were stable throughout anaesthesia, whereas rectal temperature changed significantly over time. Atipamezole at 2.5 times the medetomidine dose was sufficient for reversal and recoveries were smooth and calm in all lions independent of the atipamezole dose. First sign of recovery was observed 3-27 min after reversal. The animals were up walking 8-26 min after reversal when zolazepamtiletamine doses <1 mg / kg were used. In practice, a total dose of 6 mg medetomidine and 80 mg zolazepam-tiletamine and reversal with 15 mg atipamezole can be used for either sex of an adult or subadult lion. The drugs and doses used in this study provided a reliable, safe and reversible anaesthesia protocol for free-ranging lions.

Evaluation of butorphanol, medetomidine and midazolam as a reversible narcotic combination in free-ranging African lions (Panthera leo)

“…This is similar to other studies in lions using α 2 -adrenoceptor agonists. Bradyarrhythmias were noted in several lions and have also been observed in cheetah immobilised with BMM (Gunkel & Lafortune 2007 (Bush et al 1978;Fahlman et al 2005). Lactate values were within normal limits for domestic cats and probably did not contribute to the metabolic acidosis (King 2004).…”

“…Stable anaesthesia without a need for additional doses is a major advantage for personnel safety when working with lions. In comparison, other authors using medetomidine-ketamine and tiletamine-zolazepam-medetomidine reported sudden recovery and spontaneous movements requiring further doses of drugs (Fahlman et al 2005;Quandt 2005). Two of the three animals that were excluded from this study due to subcutaneous dart placement and prolonged drug absorption, were initially not administered the antidotes.…”

“…Tiletamine-zolazepam has been used for the immobilisation of free-ranging lions, but used alone, can cause prolonged and 5 uncoordinated inductions and recoveries (King et al 1977;Stander & Morkel 1991). When medetomidine is combined with tiletamine/zolazepam, the duration of immobilisation can be shortened and induction is smoother (Fahlman et al 2005;Jacquier et al 2006 (Verstegen & Petcho 1993;Larsen et al 2002;Kalema-Zikusoka et al 2003;Williams et al 2003;Spelman 2004;Lafortune et al 2005;Fleming et al 2006). These combinations provided stable anaesthesia with good analgesia and muscle relaxation lasting for at least 40 minutes.…”

“…Lions are anaesthetised routinely for sample collection, disease surveillance, research studies and treatment (Herbst et al 1985;Fahlman et al 2005;Jacquier et al 2006). Ideally, drugs used for the capture of free-ranging animals should induce immobilisation rapidly and reliably, provide stable cardio-respiratory function, and be fully reversible.…”

Evaluation of cardiopulmonary parameters and recovery from anesthesia in cougars (Puma concolor) anesthetized with detomidine/ketamine and isoflurane or sevoflurane

“…However, studies involving these animals require chemical restraint, given their unruly behavior in the presence of humans. Therefore, the various chemical immobilization techniques of wild mammals are an invaluable tool in the search of these animals (Hime 1974, Logan et al 1986, Barone et al 1994, Tomizawa et al 1997, Miller et al 2003, Fahlman et al 2005, Jacquier et al 2006, Carpenter & Brunson 2013.…”