Equine laminitis: induced by 48 h hyperinsulinaemia in Standardbred horses.
Authors: de Laat, McGowan, Sillence, Pollitt
Journal: Equine veterinary journal
Summary
# Editorial Summary: Equine Laminitis and Hyperinsulinaemia Whilst prolonged hyperinsulinaemia has previously been shown to induce laminitis in ponies, the relevance to horses—which are more insulin sensitive—remained unclear. de Laat and colleagues used the euglycaemic hyperinsulinaemic clamp technique to maintain elevated insulin levels in eight clinically normal Standardbred horses, comparing treatment and control groups whilst continuously monitoring hoof wall surface temperature as a potential marker of vascular changes. All four treated horses developed clinical laminitis within 48 hours, accompanied by pronounced digital pulses and elevated, less variable hoof wall temperatures, whereas none of the control horses showed signs of disease. This striking result directly demonstrates that hyperinsulinaemia alone—independent of systemic glucose dysregulation—is sufficient to trigger laminitis in healthy horses, establishing a clear mechanistic link between insulin and lamellar damage. For practitioners managing endocrinopathic horses, the findings underscore the critical importance of aggressively controlling circulating insulin levels through appropriate medication, diet and exercise protocols, as even transient periods of elevated insulin exposure present a significant laminitis risk regardless of the horse's prior clinical history.
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Practical Takeaways
- •Prompt identification and treatment of hyperinsulinaemia in horses with endocrinopathies is critical, as even 48 hours of elevated insulin levels can trigger laminitis
- •Digital pulse assessment and hoof wall temperature monitoring may serve as early warning signs of insulin-related laminitis development in at-risk horses
- •Insulin resistance management through diet, exercise, and medical intervention should be prioritized in horses with metabolic conditions to prevent laminitis
Key Findings
- •All 4 treated horses developed clinical laminitis within 48 hours of prolonged euglycaemic hyperinsulinaemic clamp infusion, compared to 0/4 control horses (P = 0.01)
- •Pronounced digital pulses were present in all treated horses but absent in controls, indicating increased vascular activity associated with laminitis development
- •Hoof wall surface temperature was significantly higher and less variable in treated horses once hyperinsulinaemia was established
- •Laminitis can be directly triggered by insulin in healthy horses with normal baseline insulin sensitivity