Among the South American camelids, alpacas (Lama pacos) and llamas (Lama glama) are both domesticated and popular species in North America. With the increase in the number of camelids as farm and pet animals, the need for veterinary care, including surgical and diagnostic procedures that necessitate anesthesia, has also increased. Acquiring venous access in South American camelids is relatively difficult1; thus, drug combinations, such as xylazine hydrochloride and ketamine hydrochloride, administered IM are commonly used as general anesthetic agents, especially for procedures of short duration.2 Additionally, the use of xylazine, a first-generation α2-adrenoreceptor agonist, in conjunction with a commercially available 1:1 mixture of tiletamine hydrochloride (a non-competitive N-methyl-d-aspartate antagonist) and zolazepam hydrochloride (a benzodiazepine) as an anesthetic combination for camelids has been reported.3 In that latter study,3 xylazine administered with the TZ combination (2 mg/kg) increased the duration of immobilization in llamas in a dose-dependent manner; however, hypoxemia developed when greater doses of xylazine were used. In comparison with xylazine, dexmedetomidine hydrochloride is an α2-adrenoreceptor agonist with high selectivity for α2- versus α1-adrenergic receptors (1,620:1, compared with 160:1 for xylazine).4,5 Dexmedetomidine induces sedation and analgesia and provides anesthetic-sparing effects in humans and other animals.6–8 To the authors’ knowledge, there is no report on the use of dexmedetomidine with a TZ combination in South American camelids.
The aim of the study reported here was to evaluate the effect of IM administration of a TZ combination with either dexmedetomidine or SS on the motor response to claw clamping, selected cardiorespiratory variables, and quality of recovery from anesthesia in alpacas. It was hypothesized that TZ treatment alone would induce only a brief duration of lack of response to claw clamping, and that concurrent IM administration of dexmedetomidine would increase this duration in a dose-dependent manner.
Presented in abstract form at the 12th World Congress of Veterinary Anaesthesiology, Kyoto, Japan, September 2015.
Diastolic arterial blood pressure
Mean arterial blood pressure
Systolic arterial blood pressure
Estimated arterial oxygen saturation
Saline (0.9% NaCl) solution
Tiletamine hydrochloride–zolazepam hydrochloride
Telazol, Zoetis, Florham Park, NJ.
Dexdomitor, Zoetis, Florham Park, NJ.
1100 Patient Monitor, Criticare Systems, Waukesha, Wis.
Dinamap Veterinary Blood Pressure Monitor 8300, Critikon, Tampa, Fla.
Pro-Vent arterial blood sampling kit, Smiths Medical, Keene, NH.
i-STAT portable clinical analyzer, Heska Corp, Loveland, Colo.
Miltex, Lake Success, NY.
SAS, version 9.3 TS Level 1M2, SAS Institute Inc, Cary, NC.
Klein L, Tomasic M, Olson K. Evaluation of telazol in llamas (abstr), in Proceedings. Annu Meet Am Coll Vet Anesth 1989;23.
2. DuBois WR, Prado TM, Ko JC, et al. A comparison of two intramuscular doses of xylazine-ketamine combination and tolazoline reversal in llamas. Vet Anaesth Analg 2004;31: 90–96.
3. Seddighi R, Elliot SB, Whitlock BK, et al. Physiologic and antinociceptive effects following intramuscular administration of xylazine hydrochloride in combination with tiletamine-zolazepam in llamas. Am J Vet Res 2013;74: 530–534.
4. Gertler R, Brown HC, Mitchell DH, et al. Dexmedetomidine: a novel sedative-analgesic agent. Proc (Bayl Univ Med Cent) 2001;14: 13–21.
5. Sinclair MD. A review of the physiological effects of α2-agonists related to the clinical use of medetomidine in small animal practice. Can Vet J 2003;44: 885–897.
6. Maze M, Tranquilli W. Alpha-2 adrenoceptor agonists: defining the role in clinical anesthesia. Anesthesiology 1991;74: 581–605.
7. Segal IS, Vickery RG, Maze M. Dexmedetomidine decreases halothane anesthetic requirements in rats. Acta Vet Scand Suppl 1989;85: 55–59.
8. Badner N, Trepanier C, Chen R, et al. Perioperative use of dexmedetomidine improves patient analgesia and provides sedation without increasing side effects. Anesth Analg 1999;88: 314.
9. Geddes LA. Method and simple apparatus for teaching the auscultatory method for measuring human blood pressure to large classes. Physiologist 1980;23: 31–32.
10. Prado TM, Doherty TJ, Boggan EB, et al. Effects of acepromazine and butorphanol on tiletamine-zolazepam anesthesia in llamas. Am J Vet Res 2008;69: 182–188.
12. Wilson RP, Zagon IS, Larach DR, et al. Antinociceptive properties of tiletamine-zolazepam improved by addition of xylazine or butorphanol. Pharmacol Biochem Behav 1992;43: 1129–1133.
13. Sweitzer RA, Ghneim GS, Gardner IA, et al. Immobilization and physiological parameters associated with chemical restraint of wild pigs with Telazol(R) and xylazine hydrochloride. J Wildl Dis 1997;33: 198–205.
14. Philipp M, Brede M, Hein L. Physiological significance of alpha(2)-adrenergic receptor subtype diversity: one receptor is not enough. Am J Physiol Regul Integr Comp Physiol 2002; 283:R287–R295.
15. Celly CS, McDonell WN, Young SS, et al. The comparative hypoxaemic effect of four alpha 2 adrenoceptor agonists (xylazine, romifidine, detomidine and medetomidine) in sheep. J Vet Pharmacol Ther 1997;20: 464–471.
16. Haskins SC. Monitoring anesthetized patients. In: Tranquilli WJ, Thurman JC, Grimm KA, eds. Lumb & Jones’ veterinary anesthesia and analgesia. 4th ed. Ames, Iowa: Blackwell Publishing, 2007; 533–558.
17. Banchero N, Grover RF. Effect of different levels of simulated altitude on O2 transport in llama and sheep. Am J Physiol 1972;222: 1239–1245.
19. Reynafarje C, Faura J, Villavicencio D, et al. Oxygen transport of hemoglobin in high-altitude animals (Camelidae). J Appl Physiol 1975;38: 806–810.