Glucose and Insulin Responses to an Intravenous Glucose Load in Thoroughbred and Paso Fino Horses.
Authors: Breuhaus Babetta A
Journal: Journal of equine veterinary science
Summary
# Editorial Summary Paso Fino horses demonstrate breed-specific insulin dysregulation independent of body condition, with baseline serum insulin concentrations and hyperinsulinaemic responses to intravenous glucose significantly elevated compared to Thoroughbreds of similar moderate weight. Breuhaus conducted intravenous glucose tolerance testing in 38 horses (14 moderate-weight Thoroughbreds, 12 moderate-weight Paso Finos, and 12 overweight Paso Finos) and found that even at moderate weight, Paso Finos exhibited markedly greater area under the insulin curve, peak insulin concentrations, and insulin-to-glucose ratios, alongside reduced glucose-to-insulin ratios and RISQI values—all indicators of impaired insulin sensitivity. Obesity amplified this breed predisposition substantially: overweight Paso Finos showed further deterioration in insulin metrics plus elevated baseline plasma glucose, suggesting a compounding genetic and nutritional effect. These findings have significant implications for endocrinopathic laminitis risk, particularly in Paso Fino horses, meaning practitioners should consider earlier metabolic screening and more conservative nutritional management in this breed, even when horses appear to maintain moderate body condition. The research provides objective evidence for a genetic basis to insulin dysregulation in Paso Finos, supporting breed-specific preventative strategies to mitigate laminitis susceptibility.
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Practical Takeaways
- •Paso Fino horses should be considered at higher risk for insulin dysregulation and endocrinopathic laminitis regardless of apparent body condition; breed-specific screening may be warranted
- •Weight management is critical in Paso Finos, as even moderate obesity significantly worsens insulin dysregulation and laminitis risk
- •Veterinarians should perform baseline insulin and glucose testing in Paso Fino horses presenting with laminitis or as part of preventative health assessment, particularly for overweight individuals
Key Findings
- •Moderate-weight Paso Finos demonstrated significantly higher baseline serum insulin concentrations and hyperinsulinemic responses to intravenous glucose compared with moderate-weight Thoroughbreds
- •Overweight Paso Finos exhibited even greater baseline insulin and glucose concentrations, plus prolonged time to peak insulin, compared with moderate-weight Paso Finos
- •Paso Fino breed shows genetic predisposition to insulin dysregulation independent of body weight, with obesity exacerbating the dysregulation
- •RISQI and glucose-to-insulin ratio were significantly lower in Paso Finos across both weight categories, indicating reduced insulin sensitivity