Exploration of Vitamin D Metabolism in Indoor-Housed Hoffmann’s Two-Toed Sloths (Choloepus hoffmanni)
American Association of Zoo Veterinarians Conference 2019
Sara E. Childs-Sanford1, DVM, MS, DACZM; Lisa M. Scanlon1, MA; Jennifer Higgins1, DVM, PhD; Isabel Jimenez2, BS; Andrew J. Makowski3, BA
1Department of Clinical Sciences, College of Veterinary Medicine, Cornell University, Ithaca, NY, USA; 2College of Veterinary Medicine, Cornell University, Ithaca, NY, USA; 3Heartland Assays LLC, Ames, IA, USA


Two-toed sloths are unique arboreal members of the superorder Xenarthra, in which disease related to calcium metabolism has been reported.1-3 This research surveyed multiple biomarkers of calcium and vitamin D metabolism, measured epidermal 7-dehydrocholesterol (7-DHC) concentrations in two locations, and evaluated the use of dried blood spots for the measurement of 25-hydroxyvitamin D (25[OH]D), in Hoffmann’s two-toed sloths (Choloepus hoffmanni). Samples were collected from nine indoor-housed healthy sloths during routine examinations. Serum was analyzed for 25(OH)D2/D3, 1,25(OH)2D2/D3, and 24,25(OH)2D2/D3 parathyroid hormone (PTH); ionized calcium (iCa); and minerals (calcium [Ca], magnesium [Mg], and phosphorus [P]). Full-thickness lumbar and abdominal skin biopsies were analyzed for 7-DHC. Whole blood was collected on a dried blood spot (DBS) card and analyzed for 25(OH)D2/D3.

All detectable vitamin D metabolites were analogues of D3, with mean±SD of 25.1±7.2 ng/ml for 25(OH)D3, 54.2±18.9 pg/ml for 1,25(OH)2D3, and 7.7±3.2 ng/ml for 24,25(OH)2D3. Mineral values were within expected ranges. Average PTH was 0.2±0.17 pmol/L, and iCa was 1.1±0.14 mmol/L. There was a significantly higher concentration of epidermal 7-DHC in the abdominal (184.4 ng/g) compared to lumbar (94.87 ng/g) biopsy samples (p=0.038). Statistical analysis using Passing-Bablok regression analysis, Bland-Altman plots, and paired t-test found good agreement between DBS and serum samples for measurement of 25(OH)D3, without constant or proportional bias. This research generates baseline data regarding vitamin D and calcium metabolism in Choloepus hoffmanni and provides a foundation for future research projects in this species, designed to improve husbandry and nutrition recommendations and reduce the incidence of disease conditions related to calcium homeostasis.


The authors thank Mazuri® Exotic Animal Nutrition, who provided the funding for this research, as well as the animal care staff of the Rosamond Gifford Zoo for assistance with sample collection and processing.

Literature Cited

1.  Gai JJ, Wack RF. Asymptomatic cystic calculus in a two-toed sloth (Choloepus didactylus). Vet Rec. 2006;159:214–216.

2.  Han S, Garner M. Soft tissue mineralization in captive 2-toed sloths. Vet Pathol. 2016;53(3):659–665.

3.  Rappaport AB, Hochman H. Cystic calculi as a cause of recurrent rectal prolapse in a sloth (Choloepus sp.). J Zoo Anim Med. 1988;19:235–236.


Speaker Information
(click the speaker's name to view other papers and abstracts submitted by this speaker)

Sara E. Childs-Sanford, DVM, MS, DACZM
Department of Clinical Sciences
College of Veterinary Medicine
Cornell University
Ithaca, NY, USA

MAIN : Mammals II : Vit D Metabolism in Hoffmann's Two-Toed Sloths
Powered By VIN