Bulgarian Journal of Veterinary Medicine, 2020 ONLINE FIRST ISSN 1311-1477; DOI: 10.15547/bjvm.2335
Original article
EFFICACY AND SAFETY OF XYLAZINE-KETAMINE COMBINATION FOR IMMOBILISATION OF CAPTIVE AFRICAN ROCK PYTHONS (PYTHON SEBAE)
S. O. ADEDIRAN1, H. O. JEGEDE2, F. M. LAWAL1, S. A. AMID1, S. Z. ABDULKADIR1, A. O. ALIMI1, A. ALIYU1 & M. BOLAJI3 1Department of Veterinary Surgery and Radiology, 2Veterinary Teaching Hospital, 3Department of Veterinary Pathology; Faculty of Veterinary Medicine, University of Ilorin, Ilorin, Nigeria
Summary Adediran, S. O., H. O. Jegede, F. M. Lawal, S. A. Amid, S. Z. Abdulkadir, A. O. Alimi, A. Aliyu & M. Bolaji, 2020. Efficacy and safety of xylazine-ketamine combination for immobi- lisation of captive African rock pythons (Python sebae). Bulg. J. Vet. Med. (online first).
The African rock python is a cosmopolitan snake in Nigeria widely kept as a zoo animal and also in recreational facilities. There is need for chemical immobilisation of this animal species for manage- mental, diagnostic and therapeutic procedures. A mixture of xylazine and ketamine (XK) was com- pared with the administration of a mixture of xylazine and normal saline solution (XS) in six captive African rock pythons in 2 trials with reference to onset and duration of anaesthesia. Changes in the heart rate (HR), respiratory rate (RR) and rectal temperature (RT) as well as selected biochemical parameters were recorded. Although there were no statistically significant (P>0.05) differences in HR and RR values between XK and XS treatments, significant (P<0.05) differences were recorded for RT. Nonetheless, the significant differences were of no clinical importance. It was therefore recom- mended to safely immobilise an African rock python using XK for a procedure lasting over 1 hour with minimal cardiopulmonary and plasma enzymatic effect. To the knowledge of the authors, this is the first study assessing the anaesthetic efficacy and safety in African Rock pythons. Key words: African rock python, anaesthesia, immobilisation, ketamine, xylazine
INTRODUCTION
The field of ophidian clinical research in Ketamine hydrochloride is a dissocia- Nigeria has experienced rapid evolution tive anaesthetic agent very popular for use and much attention in recent times; with in wildlife. It produces a trance-like state works ranging from physiology (Jegede et resulting from an electrophysiological al, 2017; 2020), anatomy (Jegede et al., dissociation between limbic and higher 2015), haemoparasitology (Jegede et al., cortical system (Allen & Macias, 2005). 2018) to anaesthesia (Abidoye et al., 2017). Although its use alone in many species Efficacy and safety of xylazine-ketamine combination for immobilisation of captive African rock ... has been of limited value, its effects have istered to each snake with a minimum 2 been improved by combination with other weeks washout period between the 2 tri- agents e.g. xylazine and diazepam (Green als, and snakes were not used during ec- et al., 1981). dysis. The pythons were manually re- African rock pythons are cosmopolitan strained and a mixture of 2% xylazine snakes in Nigeria widely kept as zoo ani- hydrochloride solution (0.3 mg/kg) and mals and in recreational facilities, al- 5% ketamine hydrochloride solution (10 though not as prevalent as they once were mg/kg) (XK) that was administered into due to international trade and gross perse- the dorsal epaxial muscle in the posterior cution for meat (Jegede et al., 2017). With third of the body, using a 23-gauge needle the widespread presence in captivity it is attached to a 2 mL syringe. A mixture of therefore imperative to perform proce- 2% xylazine hydrochloride solution (0.3 dures which would require anaesthesia mg/kg) and 0.9% normal saline solution especially with commonly available (ketamine equivolume) (XS) was adminis- agents in this part of the world coupled tered on the second trial. Both experimen- with ease of administration route (e.g. tal trials were performed in a controlled intramuscularly). environment with ambient temperature This need stimulated the authors to between 27.527.9 °C, measured using a carry out this study on the efficacy and digital thermohygrometer (WINCOM safety of xylazine/ketamine combination HTC-2, China), relative humidity ranged as an agent for immobilisation of African between 5055% . rock pythons. We therefore determined the anaesthetic indices for efficacy as- Determination of onset and duration of sessment along with cardiopulmonary anaesthesia responses, thermoregulatory responses Parameters monitored were the presence and plasma biochemical responses for or absence of spontaneous movement, safety assessment. response to tail pinch, loss of righting reflex represented by onset of anaesthesia, MATERIALS AND METHODS while recovery time was determined by observing the elicitation of righting reflex Six (6) captive African rock pythons (Py- (Fig. 1). thon sebae) were sampled in this trial. The Thermocardiopulmonary measurements snakes were housed in wire mesh cages and fed with chicks weekly. Water was Measurement of heart rate (HR), respira- provided ad libitum. All institutional and tory rate (RR) and rectal temperature (RT) national guidelines for the care and use of was done using BRAUN PM 12 Multi- animals were followed. Each snake was parameter Patient monitor. The snakes subjected to physical and clinical exami- were physically restrained with a hood nation, morphometric measurement and placed over their head, producing a calm- weighed via a secure cotton bag placed on ness required for the procedure. Five a scale. probes/clips were attached on the skin with two points close to the head, one Anaesthetic protocol midline close to the position of the heart This experiment followed a crossover and two caudally at the region before the design, in which each combo was admin- cloaca. All probes were laterally placed at
2 BJVM, ××, No × S. Adediran, H. Jegede, F. M. Lawal, S. A. Amid, S. Z. Abdulkadir, A. O. Alimi, A. Aliyu & M. Bolaji
Fig. 1. ARP with lost righting reflex and being monitored. the point where the lateral and ventral sca- Statistical analysis les meet. Readings were taken multiple times for each snake. Data were analysed using GraphPad Prism 5 (GraphPad Software Inc., La Jolla, Cali- Plasma chemistry fornia 92037, USA) and presented as Blood was collected by venipuncture of mean ± standard deviation (SD) of six the ventral coccygeal vein using a 22- snakes. Anaesthetic indices were com- gauge needle attached to a 5 mL syringe. pared using Student t-test for paired data. Each snake was restrained with the tail Monitored physiological variables were lower than the head in order to promote analyaed using analyses of variance blood pooling in the tail (Jegede et al., (ANOVA) for repeated measures and 2017). Three sets of 3 mL of blood were P<0.05 was accepted as significant. collected from each snake (pretest, post XK and post XS (immediate post recov- RESULTS ery) in heparinised appropriately labelled tubes (Silver Health Diagnostics, Nigeria). Onset of anaesthesia and duration of an- The blood was spun in a centrifuge at aesthesia with IM administration of XK 3000 rpm (905×g) for 15 min and plasma were 9.3±5.1 minutes and 89.0±24.9 mi- was decanted from the supernatant. Be- nutes respectively. XS produced no anaes- fore biochemical processing, 50 L of thetic effect. plasma was aliquoted and analysed for The HR ranges for XK and XS treat- total protein concentration, albumin, ments were between 18.0±2.9 and alanine aminotransferase (ALT), aspartate 24.0±5.8, and 18.0±7.9 and 24.0±9.3 transaminase (AST), uric acid and beats/min respectively (Table 1). The RR creatinine kinase using RT-9200 Rayto ranges for XK and XS were between Chemistry Analyzer and UV spectropho- 10.0±7.4 and 16.0±11.0, and 13.0±3.6 tometer (Rayto Life and Analytical Sci- and 16.0±6.0 breaths/min respectively. The ences Co., Ltd, China). RT ranges for XK and XS were between
BJVM, ××, No × 3 Efficacy and safety of xylazine-ketamine combination for immobilisation of captive African rock ...
Table 1. Mean cardiopulmonary and thermoregulatory responses of xylazine-ketamine anaesthesia in African rock pythons. Data are expressed as mean ± SD of six snakes
Heart rate, Respiratory rate, Rectal temperature, beats/min breathes/min °C Time XK XS XK XS XK XS interval 0 24±5.8 24±9.3 16±11 16±6.0 28±0.34 28±0.30 10 21±4.3 22±8.9 15±7.5 15±4.2 28±0.38 28±0.23 20 20±4.6 20±7.9 10±7.4 16±2.3 29±0.42* 29±0.26** 30 19±4.5 18±5.7 14±5.1 14±3.0 29±0.49**T 29±0.43*** 40 18±2.9** 19±6.5 14±7.1 14±3.5 29±0.53**T 29±0.37*** 50 20±5.7 18±7.9 16±4.5 14±5.0 29±0.56***T 30±0.60*** 60 19±5.8* 20±9.6 14±4.6 13±3.6 29±0.61***T 30±0.62*** XK: xylazine-ketamine; XS: xylazine-saline; *Р<0.05; **Р<0.01; ***Р<0.001 vs baseline (ANOVA), TP<0.05 (Student’s t-test) XK vs XS.
Table 2. Mean biochemical responses of xylazine-ketamine anaesthesia in African rock pythons. Data are expressed as mean ± SD of six snakes.
Parameters Pretest Xylazine-ketamine Xylazine-saline
Total protein, g/L 404.4 422.5 464.0 Albumin, g/L 212.2 232.0 261.8** Aspartate aminotransferase, IU/L 124.0 143.9* 213.7** Alanine aminotransferase, IU/L 8.23.3 6.34.1** 152.3* Creatinine kinase, IU/L 8.72.1 5.33.3*** 143.6* Uric acid, mmol/L 0.140.037 0.190.041 0.190.022 Lactate dehydrogenase, IU/L 11715 11516*** 15615** *Р<0.05; **Р<0.01; ***Р<0.001 xylazine-ketamine/xylazine-saline vs pretest values.
28.0±0.4 to 29.0±0.6 C (XK) and from RT between the 30th and 60th minute time 28.0±0.3 to 30.0±0.6C (XS) (Table 1). intervals. Nonetheless, the significant dif- Plasma chemistry values for pretest, ferences were of no clinical importance. XK and XS combinations are presented in Table 2. Statistically significant increase DISCUSSION in organ metabolites was obtained in AST, ALT, CK and LDH in the XS groups Due to the physiologic flexibility of rep- while increase in AST alone was obtained tiles like poikilothermy, prolonged fasting, for XK (Table 2). and swift up-regulation of the digestive Although there were no relevant system upon feed intake (Bedford & (P>0.05) differences between XK and XS Christian, 2001; Secor & Ott, 2007), refe- values for HR and RR, significant rence intervals are most times difficult to (P<0.05) differences were recorded for
4 BJVM, ××, No × S. Adediran, H. Jegede, F. M. Lawal, S. A. Amid, S. Z. Abdulkadir, A. O. Alimi, A. Aliyu & M. Bolaji ascertain (Campbell & Ellis, 2007). This though isoflurane was added to their cock- could be a reason for the huge disparity in tail. Increase in temperature after the 60th protein indices from the results here as minute could be due to wearing-off of compared to reference values reported anaesthetic agents and return of muscle earlier (Jegede et al., 2017), although activity which was more pronounced in liver enzymes were within reported ranges the XS group since this cocktail did not for the African rock python. XS combina- have an anaesthetic effect but would defi- tions showed more significant increase in nitely have had a slight sedative effect. tissue metabolites (ALT, AST, CK and Return or increase in muscle activity in LDH) than XK that showed only mildly large snakes hase been shown in literature significant increase in AST only. Al- to cause increase in cloacal temperature though conventional mammalian liver (Benedict & Fox, 1931). enzymes like ALT, AST and LDH are not There is currently no existing reliable considered to be organ specific, as their system to determine the depth of anaes- activity is abundant also in skeletal mus- thesia in reptiles (Mader & Divers, 2014), cles and kidneys, they aid detecting tissue so we worked mainly with the pres- damage especially in these vital organs ence/absence of reaction to painful stimuli (Campbell, 2014). This shows XK was e.g. tail pinch and righting reflex. Xy- less deleterious than XS in this study, as lazine-ketamine combination produced a XK produced negligible plasma bio- safe immobilisation of 89 minutes with chemical effects. minimal cardiopulmonary and thermo- There are various factors that affect regulatory effects which is longer than the plasma chemistry of the ARP (Jegede what was recorded with massive doses of et al., 2017). Anaesthetic drugs have been ketamine alone in psammophis snake shown to have effect on plasma chemistry (Abidoye et al., 2017). This will be much of snakes where Bryant et al. (2012) re- desirable as lesser doses of the drugs will ported a basophilic response with in- be used. creased globulin concentration, although Intercostal and smooth intrapulmonary there was no statistically significant in- muscles are affected by anaesthetics and crease on total protein nor albumin in our are responsible for ventilation, in the ab- study. sence of diaphragm in reptiles, apnea has Although ketamine alone has been been reported to occur in reptiles (Holz & proven to be of clinical and anaesthetic Holz, 1994). Apnea was not observed in value in snakes (Green et al., 1981) and any subject therefore eliminating the need has been recommended for superficial for assisted ventilation in XK use. surgeries and manipulations, the depth Only Schuszler et al. (2018) had used and duration have been questionable de- xylazine in snakes at the dose of 0.16 pending on factors like ambient tempera- mg/kg. Ketamine however was adminis- ture (Arena et al., 1988). tered at a lower limit of the recommended The heart rate during the period dose because some individuals after keta- ranged between 18.0±2.9 and 24.0±5.8 mine administration are reported to not beats/minute which is similar but a little awaken even for days (Bouts & Gasthuys, lower than what was recorded by 2002) and since xylazine has been re- Schuszler et al. (2018): 2344 ported to enhance its effects we used the beats/minute in constrictor snakes al- minimum possible dose even as the only
BJVM, ××, No × 5 Efficacy and safety of xylazine-ketamine combination for immobilisation of captive African rock ...
report on XK combination used 10 mg/kg Bouts, T., & F. Gasthuys, 2002. Anaesthesia in in constrictor snakes (Schuszler et al., reptiles: Part 1: Injection anaesthesia. 2018). Many other researchers have used Vlaams Diergeneeskundig Tijdschrift, 71, higher doses up to 8 mg/kg in snakes 183194. (Bouts & Gasthuys, 2002). Sub-anaes- Bryant, G. L., P. A. Fleming, L. Twomey & K. thetic doses of ketamine produce analge- A. Warren, 2012. Factors affecting hema- sia and facilitate handling by inducing a tology and plasma biochemistry in the southwest carpet python (Morelia spilota profound immobilisation effect (Mosley, imbricata). Journal of Wildlife Diseases, 2006), it is however unsure at this point if 48, 282294. the effects produced are more advanta- Campbell, T. W., 2007. Hematology of reptiles geous over ketamine alone, it is definitely In: Avian and Exotic Animal Hematology better than xylazine alone and also utilises and Cytology, eds T. W. Campbell & C. less medication (dose of ketamine). Ellis, Blackwell Publishing, Ames, IA, pp. It is therefore recommended to safely 5181. immobilise African rock pythons using Campbell, T. W., 2014. Clinical pathology of xylazine-ketamine for a procedure lasting reptiles In: Current Therapy in Reptile over 1 hour. This, to the knowledge of the Medicine and Surgery, eds D. R. Mader & authors, is the first study of its kind in J. D. Divers, Saunders Elsevier, St Louis, African Rock pythons. MO, pp. 70–92. Green, C. J., J. Knight, S. Precious, & S. Simpkin, 1981. Ketamine alone and com- REFERENCES bined with diazepam or xylazine in labora- tory animals: A 10 year experience. Labo- Abidoye, E. O., U. Effiong, P. O. Yusuf, J. O. ratory Animals, 15, 163170. Ayo & S. T. Fadason, 2017. Effect of keta- mine hydrochloride induced anaesthesia Holz, P., & R. M. Holz, 1994. Evaluation of on Psammophis sibilans. Nigerian Veteri- ketamine, ketamine/xylazine, and keta- nary Journal, 38, 178182. mine/midazolam anesthesia in red-eared sliders (Trachemys scripta elegans). Jour- Allen, J. Y. & C. G. Macias, 2005. The effi- nal of Zoo and Wildlife Medicine, 25, cacy of ketamine in pediatric emergency department patients who present with 531537. acute severe asthma. Annals of Emergency Jegede, H. O., M. L. Sonfada & S. O. Salami, Medicine, 46, 4350. 2015. Anatomical studies of the gastroin- testinal tract of the striped sand snake Arena, P. C., K. C. Richardson & L. K. Cul- (Psammophis sibilans). Nigerian Veteri- len, 1988. Anaesthesia in two species of large Australian skink. The Veterinary Re- nary Journal, 36, 12881298. cord, 123, 155158. Jegede, H. O., T. O. Omobowale, B. S. Okediran & A. A. Adegboye, 2017. Hema- Bedford, G. S. & K. A. Christian, 2001. Meta- tological and plasma chemistry values for bolic response to feeding and fasting in the the African rock python (Python sebae). water python (Liasis fuscus). Australian International Journal of Veterinary Sci- Journal of Zoology, 49, 379387. ence and Medicine, 5, 181186. Benedict, F. G., & E. L. Fox, 1931. Body tem- Jegede, H. O., B. Tomé, A. Perera & T. O. perature and heat regulation of large Omobowale, 2018. Haemogregarine ge- snakes. In: Proceedings of the National netic diversity in captive African rock py- Academy of Sciences of the United States thons from Nigeria suggests a geographical of America, Boston, Massachusetts, 17, pattern. Türkiye Parazitolojii Dergisi, 42, Suppl. 10, 584587. 28.
6 BJVM, ××, No × S. Adediran, H. Jegede, F. M. Lawal, S. A. Amid, S. Z. Abdulkadir, A. O. Alimi, A. Aliyu & M. Bolaji
Jegede, H. O., F. H. Olaifa, A. S. Adah, A. D. for Agriculture". Bucharest, Romania, 1, Adah, & T. O. Omobowale, 2020. Eryth- Suppl. 1, 474478. rocyte osmotic fragility and erythrocyte Secor, S. M., & B. D. Ott, 2007. Adaptive sizes for captive African rock pythons (Py- correlation between feeding habits and di- thon sebae). Comparative Clinical Pa- gestive physiology for boas and pythons. thology, 29, 317320. Biology of the Boas and Pythons, 1, Mader, D. R., & S. J. Divers, 2014. Current 257268. Therapy in Reptile Medicine & Surgery, st 1 edn, Saunders, W. B. Saunders Ltd. Mosley, C. A., 2006. Review of current reptile Anesthetic techniques: the do’s and don’ts. Paper received 13.01.2020; accepted for In: Proceedings of the North American publication 27.03.2020 Veterinary Conference, Orlando, Florida,
20, Suppl. 1, 16461648. Schuszler, L., D. Popovic, C. Zaha, B. Sicoe, Correspondence: D. Bumb & C. igna, 2018. observations on Dr Jegede Henry Olanrewaju Xylazine-Ketamine-Isoflurane Anesthesia Veterinary Teaching Hospital, in Constrictor Snakes. In: The Interna- University of Ilorin, P.M.B. 1515, tional Conference of the University of Ag- Ilorin, Nigeria, ronomic Sciences and Veterinary Medicine Tel: +2348038070602 of Bucharest," Agriculture for Life, Life email: [email protected]
BJVM, ××, No × 7