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

FIRST REPORT OF CHEMICAL IMMOBILIZATION AND PHYSIOLOGICAL PARAMETERS FOR FREE-RANGING MANED SLOTH (BRADYPUS TORQUATUS), USING A COMBINATION OF KETAMINE AND MEDETOMIDINE

The maned sloth (Bradypus torquatus) is an endemic and endangered species of two Brazilian states, with much unknown biological information needed to direct conservation actions. Other sloth species have been studied regarding anesthesia; however, there is a lack of anesthesia research for the maned sloth. Anesthetic data were collected from 12 free-range maned sloths that were immobilized for a field examination. Individuals were anesthetized using a combination of ketamine (4.0 mg/kg) and medetomidine (0.03 mg/kg), and antagonized with atipamezole (0.1 mg/kg). Time to induction and recovery were recorded and compared with sex and age classes. After the induction and until antagonist administration, physiological parameters (rectal temperature, heart rate, respiratory rate, and oxygen saturation) were recorded every 10 min during anesthesia and were statistically evaluated over time. Induction was fast (3.21 ± 0.76), but recovery was longer (113.3 ± 18) when compared to other studies. Induction and recovery times were not different across sex or age classes. Rectal temperature, heart rate, and oxygen saturation remained stable throughout the procedure. Respiratory rate significantly decreased over time, from 18.25 ± 7.03 to 13.17 ± 3.66 movements per minute. Our results indicate that the described combination of ketamine and medetomidine is a safe and effective choice for anesthesia of maned sloths.

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

The brown-throated sloth, Bradypus variegatus, is a common species endemic to South and Central America. Nonetheless, maintaining these animals in captivity can be challenging, and very few institutions manage to do so. The São Paulo Zoological Park Foundation is in a remnant of the Atlantic rainforest in the middle of São Paulo, the largest city in Brazil. This forest fragment has a population of B. variegatus that is geographically isolated and yet to be studied. Assessing the health status of individuals remains difficult due to the lack of reference intervals (RIs) for hematologic and biochemical variables for this species. We aimed to establish hematologic and biochemical RIs in a population of wild B. variegatus living in the largest remnant of Atlantic rainforest in São Paulo city, Brazil. Blood samples from 25 individuals of wild B. variegatus were collected and analyzed for 20 hematologic and 21 biochemical variables, using standard laboratory techniques. Each variable was statistically analyzed according to the American Society for Veterinary Clinical Pathology guidelines. The results obtained for each variable were statically analyzed, making it possible to obtain descriptive statistics for all hematologic and biochemical variables. RIs were determined for 16 hematologic variables. During the microscopic analysis, we observed anisocytosis, polychromatophils, Howell-Jolly bodies, macroplatelets, and reactive lymphocytes. The RIs and descriptive statistics described here establish important baseline numbers that could be essential for the management and treatment of both captive and wild B. variegatus sloths.

VITAMIN D STATUS OF INDOOR-HOUSED HOFFMANN'S TWO-TOED SLOTHS (CHOLOEPUS HOFFMANNI): A PILOT STUDY

Disorders of calcium homeostasis have been reported with some frequency in two-toed sloths, yet little investigation has been performed on vitamin D and mineral metabolism in these species. This study evaluates biomarkers involved in vitamin D and calcium metabolism in a group of nine managed Hoffmann's two-toed sloths (Choloepus hoffmanni), correlated with diet analysis. Serum was analyzed for both vitamin D₂ and D₃ metabolites, minerals (calcium [Ca], phosphorus [P], and magnesium [Mg]), parathyroid hormone (PTH), and ionized calcium (iCa). The diet was analyzed for proximate nutrients, minerals and vitamins D₂ and D₃, and feed intake was estimated. Average values reported for D₃ metabolites, including 25(OH)D₃, 1,25(OH)₂D₃, and 24,25(OH)₂D₃, were 25.1 ng/ml, 52.23 pg/ml, and 7.65 ng/ml, respectively. Average PTH was 0.22 pmol/L while average iCa was 1.46 mmol/L. Values reported for Ca, P, Mg were within expected ranges. Dietary concentration of D₃ was 6.7 ng/g and the average daily intake per sloth was 113.7 IU/kg body weight. No detectable levels of vitamin D₂ metabolites 25(OH)D₂, 1,25(OH)₂D₂, or 24,25(OH)₂D₂ were found in the diet or serum. These data will serve as a starting point for future investigations into the vitamin D metabolism and calcium homeostasis of two-toed sloths to improve the health in managed settings.

RENAL EVALUATION IN CHOLOEPUS SPECIES

Two species of sloths in the family Megalonychidae, Hoffmann's (Choloepus hoffmanni) and Linnaeus's (Choloepus didactylus) two-toed sloths, are commonly held in zoological institutions. Despite frequent published reports of urinary tract disease in these species, reports of diagnostics are mostly limited to descriptions of hematology and serum chemistry. In this study, repeated urinalysis, urinary chemistry, serum chemistry, and radiographs were collected opportunistically from six Hoffmann's and five Linnaeus's sloths. Proteinuria, bacteriuria, low urine specific gravity, and crystalluria were common in the absence of other signs of urinary tract pathology.