Anaesthesia of Nyala (Tragelaphus Angasi ) with a Combination of Thiafentanil (A3080), Medetomidine and Ketamine
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Article — Artikel Anaesthesia of nyala (Tragelaphus angasi ) with a combination of thiafentanil (A3080), medetomidine and ketamine D V Coopera, D Groblerb, M Bushc*, D Jessupd and W Lancee receptor binding affinity of 10 times that ABSTRACT of the sedative xylazine11,20. Medetomidine A combination of thiafentanil (A3080), medetomidine hydrochloride (MED) and ketamine is a potent sedative and analgesic with hydrochloride (KET) was evaluated in 19 boma-habituated (12 female and 7 males) and 9 anxiolytic properties11,19 and at high doses free-ranging nyala (7 male and 2 females) (Tragelaphus angasi) to develop a safe and reliable has hypnotic or anaesthetic effects19. anaesthesia protocol. Wide dosages were used safely during this study with ranges for Medetomidine provides good muscle A3080 of 45 ± 8 µg/kg with MED of 69 ± 19 µg/kg and KET of 3.7 ± 1.0 mg/kg (200 mg/ relaxation with minor physiological animal). The dosages developed on boma-habituated nyala proved to be equally effective changes in Arabian oryx (Oryx leucoryx)8 in 9 adult free-ranging nyala (7 males and 2 females). The optimum dosage for nyala was a and when combined with ketamine hy- combination of A3080 (40–50 µg/kg), MED (60–80 µg/kg) plus 200 mg of KET/animal. The drochloride (KET) has been demon- anaesthesia was characterised by a short induction, good muscle relaxation and mild strated to be effective in a broad range of hypoxaemia during monitoring the anaesthesia was rapidly and completely reversed by 11 non-domestic hoofstock . A combination naltrexone hydrochloride (30 mg/mg of A3080) and atipamezole hydrochloride (5 mg/mg of of KET and MED provided chemical MED) given intramuscularly. There was no mortality or morbidity associated with this immobilisation of impala ( protocol. Aepyceros melampus)3 and MED combined with M99 Key words: A3080, anaesthesia, atipamezole hydrochloride, ketamine hydrochloride, provided adequate immobilisation of medetomidine hydrochloride, naltrexone hydrochloride, nyala, thiafentanil, Tragelaphus Arabian oryx for at least 3 h1. KET has a angasi. synergistic effect when combined with Cooper D V, Grobler D, Bush M, Jessup D, Lance W Anaesthesia of nyala (Tragelaphus MED3,11 and is observed to potentiate the angasi) with a combination of thiafentanil (A3080), medetomidine and ketamine. Journal sedative effect of synthetic opioids16. of the South African Veterinary Association (2005) 76(1): 18–21 (En.). Conservation and A potent and selective "2 adrenoreceptor Research Center, Smithsonian National Zoological Park, 1500 Remount Road, Front Royal antagonist, atipamezole hydrochloride Virginia, VA 22630, USA. (atipamezole) is highly effective in revers- ing sedation/anaesthesia induced by MED or MED/KET combinations in some 11,19 INTRODUCTION allow for individual selection of animals species , but other species such as Nyala (Tragelaphus angasi) are popular (e.g. trophy bulls). Reliable anaesthesia impala show re-sedation from MED 3 and economically important species of nyala has been difficult as shown by following atipamezole . stocked on many South African game previous reports that nyala are difficult to A pilot study was conducted on 5 farms and a flagship species in selected reliably anaesthetise and exhibit high boma-confined nyala (4 females and 1 national parks. They prefer a habitat of levels of stress-related morbidity and male) weighing 48±7kg(average ± SD) dense bush, which leads to complications mortality9 (DVC and DG, pers. obs., 2004). using a combination of A3080 (44 ± when field anaesthetic protocols with Thiafentanil (A3080) is a synthetic 14 µg/kg) and 200 mg of ketamine hydro- long induction times are used. Nyala are fentanyl derivative with a rapid, pro- chloride (KET)/animal (4.3 ± 0.6 mg/kg). fairly delicate antelope with thin skin and nounced opioid agonist activity. It has a This combination resulted in initial signs are predisposed to stress and capture shorter duration of action than carfentanil in 1:15 (min:sec) with recumbency in 4 of myopathy6,7,14. Traditionally, nyala are citrate (carfentanil) or etorphine hydro- 5 animals at 3:36 ± 2:18 min. The nyala captured by a net method2,7 and given a chloride (M99) and is only slightly less receiving the lowest dose of A3080 tranquiliser as rapidly as possible to pre- potent than carfentanil12,15,17,18. A3080 (24 µg/kg) did not become recumbent, but vent stress and myopathy6,7. There is a given at doses approximately 3.75 and 7.5 was easily caught. The induction time need to develop a rapid and safe field times greater than carfentanil produced did not decrease as the dose of A3080 anaesthesia protocol for nyala applicable more rapid immobilisation in elk15. A3080 increased. The quality of anaesthesia was for remote delivery of drugs, which would has a shorter induction time that carfentanil judged to be poor due to excessive strug- 16 13 aEzemvelo Kwa-Zulu Natal Wildlife, Private Bag X01, by 26–65 % in cervids . In impala and gling with difficulty of restraint, which St Lucia, 3936 South Africa. elk18 the induction time of A3080 was dose limited collection of physiological data. bSouth African National Parks, Kruger Park, South Africa. The animals had elevated respiration Present address: Catchco Africa, Highlands North, 2037 dependent. Naltrexone hydrochloride South Africa. (naltrexone) produces rapid and complete (31 ± 8/min), tachycardia (245 ± 22/min) cConservation and Research Center, Smithsonian Na- reversal of A3080 with no re-narcoti- and elevated rectal temperature (39.6 ± tional Zoological Park, 1500 Remount Road, Front Royal 13,17,18 Virginia, VA 22630, USA. sation . 0.5 °C) with good haemoglobin oxygen dInternational Wildlife Veterinary Services, 1451 Shaffer Medetomidine hydrochloride (MED) is saturation (91 ± 5 %). Owing to poor Rd., Santa Cruz, CA 95060. an imidazole-based compound with quality of the anaesthesia and the concern eWildlife Pharmaceutical Inc., Fort Collins, Colorado 80524, USA. potent selective and highly specific ago- for the welfare of the animal, naltrexone *Author for correspondence: [email protected] nistic activity at both pre and post-synap- (30 mg/mg of A3080) was given intramus- 2 19,20 2 Received: August 2004. Accepted: November 2004. tic " adrenoreceptors . It has an " cularly (i.m.) to end the procedure within 18 0038-2809 Tydskr.S.Afr.vet.Ver. (2005) 76(1): 18–21 10 min of induction. The animals stood in Table 1: Mean ± SD dosage rates and response times in nyala anaesthetised with A3080/ 1:15 ± 0:21 min and rapidly returned MED/KETM. towards normal. Group 1 Group 2 The objective of this study was to deter- mine if the rapid induction attribute of n 19 ± 9 ± A3080 could be combined with the potent Weight (kg) 62 ± 25 106 ± 26 2 selective " effects of MED plus the syner- A3080 (µg/kg) 45 ± 8 43 ± 3 16 gism of KET with opoids and MED to MED (µg/kg) 69 ± 19 63 ± 9 produce a rapid-acting, balanced combi- KET (µg/kg) 3.7 ± 1.0 2.0 ± 0.7 nation applicable to remote drug delivery Initial signs (min) 1:22 ± 0:21 1:48 ± 0:18 in this species’ dense habitat. The anaes- Recumbency (min) 3:11 ± 1:09 4:28 ± 1:48 thesia should be rapidly and completely NAL (mg/kg) 1.8 ± 0.7 1.3 ± 0.1 reversible. Previous reports of this combi- ATP (µg/kg) 340 ± 100 310 ± 50 Up (min) 2:28 ± 0:42 ** nation have been successful in producing rapid, safe and completely reversible **These nyala were given tranquilisers and crated; therefore the ‘Up time’ was compromised. anaesthesia in Lichtenstein's hartebeest (Sigmoceros lichtensteinil)5, roan antelope Group 2 consisted of free-ranging Animal Health, Exton, PA) at a dosage of (Hippotragus equines)4 and gemsbok (Oryx animals darted from a vehicle at a range of 5 mg/mg of MED. The time to stand- gazelle)10. 25–40 m. The 5 adult (trophy) males ing and completeness of recovery were (approximately 120 kg) received A3080 recorded. The anaesthetised free-ranging MATERIALS AND METHODS (5 mg) plus MED (7 mg) and 200 mg of nyala were crated and given tranquilisers The study was conducted with boma- KET/animal. The 2 adult female (approxi- [150 mg perphenazine enanthate (Trilifon habituated and free-ranging nyala. The mately 60 kg) received A3080 (2.5 or 3 mg), Enanthate, Schering-Plough, Isando, Kwa-Zulu Natal Nature Conservation MED (4.5 or 5 mg), respectively, plus South Africa) i.m. plus 15 mg haloperi- Service captured the animals using physi- 200 mg of KET/animal. Following moni- dol (Haloperidol®, Kyron Laboratories, cal methods routine in the management toring these animals were placed in crates Johannesburg) intravenously (i.v.)] at the of this species in the Hluhluwe Umfolozi and transported to holding bomas. time of the naltrexone and atipamezole Park. The animals included both sub- Data collected included the interval injections. This is the standard protocol of adult and adult males and females that from injection to 1st signs of drug effect the Natal Parks Board Game Capture Unit were conditioned to the bomas for at least and the time the animal became recum- when placing field captured nyala into a 3 weeks prior to the study. The diet bent. In Group 1 initial physiological data boma, therefore the full extent of recovery consisted of lucerne hay and commercial collection (Initial Time) began in the boma from the naltrexone and atipamezole antelope cubes and freshly cut browse. after the animal became recumbent could not be evaluated completely in this Water was available ad-libitum. To mimic (2:30 ± 0:50 min) and could be approached group. field conditions, food and water was not and safely handled. The ‘Time 0’ was after withheld prior to the anaesthesia. Their the animal was removed from the boma, RESULTS body condition and pelage was rated weighed and placed in sternal recumbency Group 1 received a combination of good by local biologists.