Insulin Resistance as a Result of Body Condition Categorized as Thin, Moderate, and Obese in Domesticated U.S. Donkeys (Equus asinus).
Authors: Pritchard Abby, Nielsen Brian, McLean Amy, Robison Cara, Yokoyama Melvin, Hengemuehle Susan, Bailey Simon, Harris Patricia
Journal: Journal of equine veterinary science
Summary
# Editorial Summary Obesity in donkeys, driven by their inherent metabolic efficiency and sedentary lifestyles as companion animals, poses significant health risks including laminitis and insulin resistance; however, research documenting these metabolic consequences in donkeys has lagged considerably behind equivalent studies in horses and ponies. Researchers compared glucose-insulin dynamics across 24 donkeys stratified by body condition score (thin, moderate, and obese; n=8 per group) using frequently sampled intravenous glucose tolerance testing with subsequent MINMOD analysis to quantify insulin sensitivity. Obese donkeys demonstrated significantly elevated basal insulin concentrations compared to both moderate (P=0.02) and thin cohorts (P=0.01), with a broader trend suggesting that increased body condition score progressively reduced insulin sensitivity across groups (P=0.06). These findings suggest donkeys respond to overconditioning in mechanistically similar ways to horses and ponies, with chronically elevated fasting insulin representing a plausible pathway to metabolic dysfunction and serious conditions such as laminitis. For practitioners managing donkeys, these results underscore the importance of maintaining ideal body condition through careful caloric management and monitoring basal insulin as an early metabolic health marker, particularly in animals with evidence of weight gain.
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Practical Takeaways
- •Monitor body condition score carefully in companion donkeys, as obesity significantly elevates basal insulin and may impair insulin sensitivity, increasing laminitis and metabolic disease risk
- •Donkeys' naturally higher digestive efficiency and lower energy expenditure compared to horses makes them prone to rapid weight gain—adjust feeding and activity accordingly
- •Elevated basal insulin in overweight donkeys is a measurable metabolic warning sign; consider glucose-insulin testing for donkeys with moderate to high BCS as part of preventive health screening
Key Findings
- •Basal insulin was significantly highest in obese donkeys compared to moderate (P = 0.02) and thin donkeys (P = 0.01)
- •Body condition score showed an overall trend toward lowering insulin sensitivity across groups (P = 0.06)
- •Obese donkeys exhibited similar glucose-insulin dynamics patterns to obese horses and ponies
- •Higher basal insulin concentrations in obese donkeys may contribute to chronic health conditions