Hindgut Acidosis: What Every Horse Owner Should Know
What Is Hindgut Acidosis?
Hindgut acidosis occurs when the pH of the cecum and large colon drops below its normal range (approximately 6.5 to 7.0). This happens when rapidly fermentable carbohydrates reach the hindgut in excessive quantities. The bacteria in the hindgut ferment these carbohydrates quickly, producing lactic acid and other organic acids that lower the pH.
How It Develops
A horse consumes a grain-based meal. The small intestine, with its limited amylase production, cannot digest all the starch before it passes into the hindgut. Once in the hindgut, the starch is rapidly fermented by lactic acid-producing bacteria. These bacteria thrive on starch and multiply quickly, outcompeting the fibre-fermenting bacteria that normally dominate the hindgut ecosystem.
The Consequences
Hindgut acidosis can trigger a cascade of problems. The acidic environment damages the mucosal lining of the gut, potentially increasing intestinal permeability. Toxins produced by dying bacteria can enter the bloodstream, contributing to systemic inflammation. In severe cases, this can lead to laminitis, a painful and potentially career-ending condition affecting the hooves.
Prevention Strategies
The most effective prevention is dietary management. Limiting grain meals to no more than 2 kg per feeding, increasing forage intake, and choosing feeds with lower starch content all help reduce the amount of starch reaching the hindgut.
Supporting the small intestine's capacity to digest starch before it reaches the hindgut is another approach. Providing exogenous digestive enzymes, particularly amylase, can help bridge the gap between starch intake and the horse's natural enzymatic capacity.