Plasma endotoxin levels in horses subjected to carbohydrate induced laminitis.

The study observes the connection between plasma endotoxin levels in horses and the development of laminitis following high carbohydrate intake. It reveals that majority of horses experienced level three lameness (based on the Obel grading system) and a corresponding increase in plasma endotoxin levels after excessive carbohydrate consumption.

Research Objective and Methodology

• The primary objective of the research was to understand the relationship between the diet of horses (specifically high carbohydrate intake) and the resulting incidence of laminitis, a painful condition in horses affecting the horse’s hooves.
• The study made use of the carbohydrate overload model to induce laminitis in 20 horses, where the horses were subjected to an unusually high level of carbohydrates in their diet.
• The team then tracked any corresponding increase in plasma endotoxin levels and monitored the development of lameness in the horses based on the Obel Grading System, a widely used scoring system for laminitis in horses.

Key Findings

• 65% of the horses developed a severe level of lameness (Obel Grade 3) within 56 hours of the carbohydrate overload.
• Simultaneously, the plasma endotoxin levels in these horses increased from control levels of less than 0.1 ng/litre to values between 2.4 to 81.53 ng/litre.
• On closer analysis, it was found that a large majority (85%) of the lame horses demonstrated such a spike in plasma endotoxin levels.
• Most horses (92%) with Obel Grade 3 lameness showed increased endotoxin levels due to infection with Gram-negative bacteria.
• The study also documented a two-peak increase in endotoxin levels in nearly half (45%) of horses which exhibited both lameness and endotoxaemia (presence of endotoxins in the blood). The first peak occurred around 32 hours post-overload, and the second around 48 hours.
• In cases where only one peak was recorded, it occurred at an average of 24 hours post-overload in four horses. In three other horses, the peak was noted at either 48 or 56 hours after carbohydrate overload.

Conclusion & Implications

• The study conclusively establishes a link between high carbohydrate intake and the onset of laminitis in horses.
• This adds to the body of knowledge on mitigating factors in laminitis management in horses, and the evidence may potentially prompt dietary guidelines adjustments.
• The finding is particularly significant to horse owners and trainers, who can consider dietary changes to reduce the risk of laminitis in their animals.