LAUSR

Abstract: Egyptian fruit bats (Rousettus aegyptiacus) are commonly held within zoos and research facilities. Despite this popularity, there have been no publications regarding normal bone density or bone mineral concentration and few publications regarding the normal dietary requirements of calcium, phosphorus, and vitamin D (25-hydrox-vitamin D3 [25(OH)D3]) for the species. A clinical investigation into frequent fractures in a zoo population of 23 adult male Egyptian fruit bats used dual-energy X-ray absorptiometry (DXA) to evaluate bone mineral density (BMD) and bone mineral content (BMC) prior to and after dietary adjustment of calcium and phosphorus. This study documents BMD, BMC, serum trace minerals, and serum levels of 25(OH)D3 within this population and includes postmortem bone density and bone ash from a subset of bats that died during the study period. A handheld point-of-care analyzer was utilized to assess ionized calcium and electrolytes (sodium, potassium, chloride, total CO2), glucose, blood urea nitrogen, and creatinine at each DXA time point to contribute to published reference ranges for this species. This study identified a significant (P < 0.001) increase in BMC over 15 mon (4.71–8.26 g) following additional calcium and phosphorus supplementation in the diet. The BMD also trended toward a significant increase (0.124–0.274 g/cm2, P < 0.053). Additional studies documenting normal bone density that include both sexes and possibly free-ranging bats consuming a natural diet are recommended to determine normal values for R. aegyptiacus.