Charles O. Cummings, Daniela Bedenice, Sarah E. Wills, Elizabeth Rozanski, Eva Maria Greunz, Anne K.H. Krogh, Bo Wiinberg
Journal of Zoo and Wildlife Medicine 53 (1), 133-140, (11 March 2022) https://doi.org/10.1638/2021-0033
Thromboelastography (TEG) provides a global assessment of hemostasis and fibrinolysis and has broad applications to identify and monitor coagulation dysfunction in veterinary patients. Although alpacas are susceptible to a wide variety of coagulopathies, the assessment of TEG has not been reported in clinically healthy alpacas to date. The purpose of this study was to evaluate the analytical performance of recombinant human tissue factor (rhTF)– and kaolin-activated TEG and to establish reference intervals for TEG parameters (reaction [R] and clotting [K] times, angle [α], maximum amplitude [MA], and shear elastic modulus [G]) in healthy, adult alpacas. Kaolin and rhTF-activated TEG were performed using citrated whole blood samples from 20 clinically healthy, nonpregnant, adult Huacaya alpacas each after 30 min of sample storage at room temperature. Six individuals of a related species, dromedary camels, were also sampled for comparative purposes. All data were presented descriptively, assessed for normality, and compared using either independent-sample t tests or Mann-Whitney U tests, with P ≤ 0.05 considered significant. Reference intervals were calculated using a robust method and Box-Cox–transformed data. Mean TEG values (reference intervals) were determined for rhTF-activated TEG as follows: R 6.99 min (3.41–12.71), K 3.43 min (1.61–6.42), α 48.51° (27.21–67.38), MA 52.05 mm (21.53–65.92), and G 5.71 kdyn/cm2 (1.87–9.60), while mean values (reference intervals) for kaolin-activated TEG included R 7.72 min (4.48–11.43), K 4.24 min (2.03–9.20), α 45.06° (23.66–64.20), MA 52.18 mm (33.49–66.63), and G 5.78 kdyn/cm2 (NR–9.66). None of the measured TEG values differed significantly between activators, suggesting that activator choice may have a limited effect on TEG parameters in healthy alpacas. TEG results in alpacas were comparable to those of dromedary camels. These results will thus provide a useful starting point in the evaluation of hemostasis in adult camelids.