PHYSIOLOGIC AND SERUM BIOCHEMISTRY VALUES IN FREE-RANGING HOFFMANN'S TWO-TOED (CHOLOEPUS HOFFMANNI) AND BROWN-THROATED THREE-TOED (BRADYPUS VARIEGATUS) SLOTHS IMMOBILIZED USING DEXMEDETOMIDINE AND KETAMINE

Abstract

Dexmedetomidine, a highly selective alpha-2 adrenergic agonist and dextrorotary enantiomer of medetomidine, was combined with ketamine and used to immobilize 14 free-ranging Choloepus hoffmanni (Hoffmann's two-toed sloths) and 11 Bradypus variegatus (brown-throated three-toed sloths) in Upala, Costa Rica. Following intramuscular injection of ketamine (2.1 mg/kg) and dexmedetomidine (11 microg/kg), heart rate, respiratory rate, and indirect systolic blood pressure were measured every 5 min for a total of 25 min. An iStat (CG8+) was used to evaluate serum biochemical and hematologic values during anesthesia. After 30 min of anesthesia, atipamezole (0.13 mg/kg) was administered intramuscularly, which resulted in rapid and smooth recoveries. Mean heart rate and respiratory rate remained unchanged in both C. hoffmanni and B. variegatus over time. Progressive decreases in mean indirect systolic blood pressure were documented in both species. Results of this study suggest a combination of dexmedetomidne and ketamine is a safe and effective anesthetic protocol for use in free-ranging C. hoffmanni and B. variegatus. Similar to other alpha-2 adrenergic agonist-based immobilization protocols, close monitoring of cardiovascular and respiratory parameters are recommended. This study also provides serum biochemical and hematologic data in free-ranging C. hoffmanni and B. variegatus.

Hematologic and biochemical reference intervals of brown‐throated sloths (Bradypus variegatus)

“…This is the first study that provides population‐based RI for Bradypus variegatus . There are only a few reports of hematologic and plasma biochemical values in B. variegatus , 11,14‐16 all had smaller sample sizes (10–19 individuals) than in the present study. Importantly, none of these prior studies calculated population‐based RIs using statistical analysis.…”

“…A direct comparison of the descriptive values presented here with previously reported numbers is challenging. There are many differences between our study and previous reports: (i) the number of individuals is often smaller; (ii) the geographic origin of the samples is different with distinct biotic and abiotic factors (ie, captivity animals); 11,14‐16 (iii) sample collection conditions differ (ie, anesthesia); 11 and finally, (iv) some of the samples were either analyzed by distinct processes, 15 or did not describe the methodology used 14 . With so many confounding factors and smaller sample sizes, it is impossible to disambiguate real population differences from methodologic and geographic differences.…”

“…PCVs were determined using the microhematocrit technique, using microcapillary tubes that were centrifuged for 5 minutes at approximately 16 128 g. MCVs, MCH, and MCHC were calculated according to RBC, hemoglobin, and PCVs results. 11 Reticulocytes were determined by mixing one part blood with one part methylene blue. After 5 minutes, this mixture was used to prepare a thin blood smear, which was microscopically analyzed.…”

Parámetros sanguíneos y perfil de hormonas reproductivas de hembras de Choloepus hoffmanni en cautiverio

“…Solid lines represents P 4 and dotted lines corresponds to E 2 . (Durán, 2005;Hayssen, 2011;Kinney, Cole, Vaughan, & Sladky, 2013;Miller & Fowler, 2015); de igual manera, hay concordancia de los resultados hematológicos con lo reportado para las especies Choloepus didactylus (Vogel, Vie, Thoisy, & Moreau, 1999) y Bradypus variegatus (Araújo, 2006). Aunque C. didactylus no es la misma especie de este estudio, sí es del mismo género Choloepus, por lo que representa una especie simpátrica para el hemisferio sur y por tanto, los valores en nuestro estudio presentan comportamientos similares.…”

Unusual predation of Hoffmann’s two-toed sloth (Choloepus hoffmanni) by a coyote (Canis latrans) in Costa Rica

“…This species is included in CITES Appendix III (CITES, 2017) and considered as Least Concern according to the International Union for the Conservation of Nature (Plese & Chiarello, 2014). In Costa Rica, Hoffmann's two-toed sloth has been subjected to many investigations, including habitat use studies (Vaughan et al, 2007) and health of both captive and wild sloths (Zeledón et al, 1979;Hanley et al, 2008;Sibaja-Morales et al, 2009;Kinney et al, 2013), but there have been no reports of predation.…”