Advances in Animal and Veterinary Sciences Research Article Immobilization and Anaesthesia in Asiatic Lions (Panthera leo persica) 1 2 1 MURUGAN BHARATHIDASAN , BENJAMIN JUSTIN WILLIAM *, RAMAMURTHY JAYAPRAKASH , THANDAVAN 2 3 1 ARTHANARI KANNAN , RAJARTHANAM THIRUMURUGAN , RAVI SUNDAR GEORGE 1Department of Veterinary Surgery and Radiology, Tamil Nadu Veterinary and Animal Sciences University, India; 2Centre for Stem Cell Research and Regenerative Medicine, Madras Veterinary College, Chennai – 600007, Tamil Nadu, India; 3Veterinary Assistant Surgeon, Arignar Anna Zoological Park, Chennai, India. Abstract | A total of 12 trials were conducted in 8 Asiatic and hybrid lions (Panthera leo persica) for diagnostic and surgical procedures. All the lions were immobilized with a combination of xylazine and ketamine at the rate of 1.00 mg/kg and 2.00 mg/kg body weight, respectively, using darts based on assumed body weight. Ketamine and propofol intravenously were used as induction agents sufficiently to achieve deep plane of anaesthesia and good jaw muscle relaxation in six trials each of treatment I and II. The commercially available large animal endotracheal tubes and cus- tom made silicon medical grade tubes were used for intubation either by direct visualization or by digital palpation of glottis. Anaesthesia was maintained with isoflurane. The study revealed that the young lions required 1.08±0.10 and 2.70±0.26 mg/kg and adult required 1.06±0.30 and 2.64±0.08 mg/kg body weight of xylazine and ketamine, respec- tively for immobilization. Ear flick reflex was taken as an indicator for safe and appropriate time for approaching the lion after immobilization, which was completely abolished only after 1.37 and 2.01 minutes after recumbency in young and adult lions, respectively. Based on the radiographic distance between snout and distal larynx endotracheal tubes of one meter length and 30 mm diameter were suitable for intubation and the larynx was located between 5th and 6th cervical vertebrae. The dose of ketamine and propofol required for induction was 1.00 mg/kg and 1.92 mg/kg body weight, respectively, in immobilized lions and intubation could be safely performed under propofol induction by oro- pharyngeal digital palpation of glottis for administration of inhalant anaesthetics. Both ketamine and propofol could be used as induction agents in lions immobilized with xylazine-ketamine and for further maintenance with isoflurane. Keywords | Asiatic lions, Anaesthesia, Ear flick reflex, Intubation, Xylazine, Ketamine, Propofol Editor | Kuldeep Dhama, Indian Veterinary Research Institute, Uttar Pradesh, India. Received | December 04, 2015; Revised | January 29, 2016; Accepted | January 30, 2016; Published | March 04, 2016 *Correspondence | Benjamin Justin William, Centre for Stem Cell Research and Regenerative Medicine, Madras Veterinary College, Chennai, Tamil Nadu, India; E-mail: [email protected] Citation | Bharathidasan M, William BJ, Jayaprakash R, Kannan TA, Thirumurugan R, George RS (2016). Immobilization and anaesthesia in Asiatic lions (Pan- thera leo persica). Adv. Anim. Vet. Sci. 4(3): 134-144. DOI | http://dx.doi.org/10.14737/journal.aavs/2016/4.3.134.144 ISSN (Online) | 2307-8316; ISSN (Print) | 2309-3331 Copyright © 2016 Bharathidasan et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. INTRODUCTION duce convulsions in lions. Ketamine has a shorter duration of action and has the disadvantages of poor muscle relaxa- hemical immobilization and anaesthesia is an integral tion, excessive salivation and lack of specific antagonistic to component in conservation, diagnostic and surgical reverse the action. Frequently alpha-2 adrenergic agonists Cprocedures in wild animal species. The risks involved in are combined as adjunct to promote the analgesic action, chemical immobilization and anaesthesia in lions are loss muscle relaxation, increase the duration of immobilization of thermoregulation, rigidity, depressed respiration, shock, and to reduce the dose of ketamine (Swan, 1993). Propo- unpredictable recovery, delayed recovery and convulsions fol is an alkyl phenol, ultra-short acting non-barbiturate, (Wack, 2003; Gunkel and Lafortune, 2008). Commonly which readily induces reliable anaesthesia in one arm- used anaesthetic drugs; ketamine and tiletamine often in- brain circulation. March 2016 | Volume 4 | Issue 3 | Page 134 Advances in Animal and Veterinary Sciences Inhalant anaesthetics are safe for long-term anaesthesia time for recumbency and quality of immobilization were due to the merit of less stress, smooth and short recov- compared between young and adult lions. The quality of ery, ease in change of depth of anaesthesia and possibility immobilization was graded as 1 (excellent), 2 (good), 3 of adopting resuscitative methods at times of emergency. (fair) and 4 (poor) on the basis of ataxia, attempts for ster- Relatively complicated anatomy and position of the larynx nal recumbency, symptoms of CNS stimulation, stumbling at the level of 5th cervical vertebrae and structures in the and requirement of additional dose of immobilizing agents pharynx (Weissengruber et al., 2002) always make the task (Wenger et al., 2010). of intubation more difficult, apart from added fear in li- ons and other members of genus Panthera when compared EAR FLICK REFLEX with domestic cats. Once the animals attained lateral recumbency, they were approached from outside the cage and the pinna was gen- The study was designed to assess the reliability of ear tactile tly stimulated with a stick, sufficiently to stretch the auric- reflex as an indicator to assess the depth of anaesthesia in ular muscles to elicit the ear twitch reflex (Figure 1) and lions immobilized with xylazine and ketamine combina- the ear flick reflex was scored (Gatesman and Wiesner, tion and suitability of ketamine/propofol with isoflurane 1982). Score 1: Unsatisfactory - The animal could actively for anaesthesia in Asiatic and hybrid lions. move its limb and even stand up when the ear pinna was stimulated, Score 2: Light level - Ear twitch was present MATERIALS AND METHODS and feeble movements could be noticed and Score 3: Sat- isfactory - Absence of ear twitch reflex. Additional incre- The study was conducted in Asiatic lions (Panthera leo per- mental doses of xylazine and ketamine were administered sica) and hybrid lions housed in Arignar Anna Zoological to achieve recumbency and immobilization characterized Park, Vandalur, Chennai and referred to the Department by absence of ear flick reflex, if required. The time taken of Veterinary Surgery and Radiology, Madras Veterinary in minutes for complete absence of ear flick reflex follow- College Teaching Hospital for various diagnostic and sur- ing darting was recorded.The data were compared between gical procedure. A total of 12 trials were conducted in 8 the young and adult lions. Asiatic lions; which involved 4 trials with 2 young lions within 2 to 4 years of age and 8 trials with 6 adult above 6 years of age (Schaller, 1972). The study was conducted in accordance with Indian Wild Animal Protection Law 1972, amended in 1992. The procedure was also approved by the Dean, Faculty of Veterinary Science, Tamil Nadu Veterinary and Animal Sciences University. The proce- dures performed were radiography of hip, thorax, digits and tibia, wound dressing and bandaging and surgical pro- cedures like vasectomy, tail amputation and phacoemulsifi- cation and extraction of cataract lens. The animals includ- ed in the study were apparently healthy and assessed for their fitness based on physical status and behaviour before immobilization and anaesthesia. The animals intended for elective procedures were visited two days prior to the study and their physical condition, feeding and voiding habits were observed. Previous history of any ailment, deworming schedule and vaccination schedule were taken into account. The weight of the lions ranged from 90 to 145 kg. IMMOBILIZATION The lions were confined in cages 24 hours prior to the procedure and feed was withheld; but free access to wa- ter was allowed (Epstein et al., 2002). All the lions were immobilized with a mixture of xylazine hydrochloride (1.00 mg/kg) and ketamine hydrochloride (2.50 mg/kg), intramuscularly in the upper hind limb or shoulder area (Meltzer, 1999) using blowgun, based on the assumed body weight. Dose of xylazine and ketamine with respect to actual weight, time taken for in-coordination and ataxia, Figure 1: Stimulation of ear flick reflex after immobilization March 2016 | Volume 4 | Issue 3 | Page 135 Advances in Animal and Veterinary Sciences HANDLING, SAFETY MEASURES AND TRANSPORTATION ficient for intubation. No anaesthetic was administered in The immobilized lions were blind folded and the fore limbs lions, which were already in the surgical plane of anaes- were hobbled (Wenger et al., 2010; Kock and Burroughs, thesia with the immobilization doses of xylazine and keta- 2012). Intravenous catheters (18 gauge) were fixed either mine and they were allotted to treatment I. The induction in cephalic or saphenous vein. The actual weights of the dose of ketamine and propofol required to abolish pedal lions were recorded and the lions were transported to the reflex and to effect complete jaw muscle relaxation was cal- Zoo Veterinary Hospital for further procedures. culated. The quality of induction was scored