Metabolic Bone Disease in Captive Flying Foxes: A Conceptual Framework and Future Perspectives

Area of Science:

• Veterinary Medicine
• Comparative Physiology
• Zoology

Background:

• Metabolic bone disease (MBD) in Pteropus species is frequently observed in captive settings.
• MBD is associated with fruit-based diets lacking calcium, vitamin D precursors, and protein, alongside insufficient ultraviolet B (UVB) exposure.
• Endocrine factors like parathyroid hormone (PTH), fibroblast growth factor 23 (FGF23), calcitonin, and calcitriol may play a role, but data in flying foxes are limited.

Purpose of the Study:

• To synthesize current knowledge on the etiology, pathophysiology, and clinical presentation of MBD in captive flying foxes.
• To identify key nutritional and environmental risk factors contributing to MBD.
• To summarize evidence-based strategies for preventing MBD and enhancing skeletal health.

Main Methods:

• This study is a narrative review synthesizing existing literature.
• Data sources include zoological surveys, clinical observations, and comparative mammalian physiology studies.
• Focus is on Pteropus species, with emphasis on Pteropus vampyrus.

Main Results:

• Nutritional deficiencies (calcium, vitamin D, protein) and inadequate UVB exposure are primary risk factors for MBD.
• While comparative physiology suggests endocrine involvement, direct data in flying foxes are scarce.
• Evidence is largely derived from juvenile Pteropus vampyrus, limiting generalizability to other species.

Conclusions:

• Captive flying foxes are susceptible to MBD due to specific dietary and environmental factors.
• Further research, including controlled studies, is needed to fully understand species-specific endocrine roles and improve management strategies.
• Implementing preventive nutritional and environmental management is crucial for improving skeletal health and welfare in managed Pteropus populations.