Transient alteration in intestinal permeability to technetium Tc99m diethylenetriaminopentaacetate during the prodromal stages of alimentary laminitis in ponies.
Authors: Weiss, Evanson, MacLeay, Brown
Journal: American journal of veterinary research
Summary
# Editorial Summary: Intestinal Permeability and Laminitis During the early stages of carbohydrate-induced laminitis in ponies, the intestinal mucosa becomes transiently hyperpermeableâ€"a finding that may help explain the pathophysiological cascade leading to this devastating condition. Weiss and colleagues administered a carbohydrate overload to 15 ponies and measured intestinal permeability using radioactive technetium Tc99m DTPA, tracking its urinary excretion and blood levels over an 8-hour period in control animals and at two post-challenge timepoints. Urinary excretion of the tracer increased dramatically from 2.45% in controls to 16.67% between 4â€"12 hours post-overload, before declining to 3.57% at 20â€"28 hours, demonstrating a marked but short-lived breach in mucosal integrity. This transient hyperpermeability likely allows endotoxins and other bacterial products to cross the intestinal barrier and enter systemic circulation during the critical prodromal phase. For practitioners, this research underscores why early dietary intervention and management of hindgut fermentation is crucial in laminitis prevention, and suggests that agents protecting mucosal integrity during high-risk feeding events warrant further investigation.
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Practical Takeaways
- •Carbohydrate overload causes a window of compromised intestinal barrier function in the first 4-12 hours, during which endotoxin translocation may trigger laminitis—emphasizing the critical importance of preventing grain/carbohydrate accidents
- •The transient nature of increased permeability suggests early intervention (within hours of carbohydrate overload) may limit endotoxin absorption and subsequent laminitis development
- •This mechanism explains why alimentary laminitis develops rapidly after carbohydrate overload and supports protocols addressing intestinal health and barrier function in prevention and early management
Key Findings
- •Urinary excretion of 99mTc-DTPA increased dramatically from 2.45% in control ponies to 16.67% at 4-12 hours post-carbohydrate overload, indicating transient increased intestinal permeability
- •Intestinal permeability returned toward baseline by 20-28 hours post-carbohydrate overload (3.57% urinary excretion)
- •Marked but transient increase in mucosal permeability occurs during early prodromal stages of alimentary laminitis
- •Increased intestinal absorption of endotoxin-like substances may be an initiating mechanism in carbohydrate-induced laminitis pathogenesis