In the second part of our blog series where we are looking at the connection between what happens in your horse’s hindgut and the painful inflammation in their hooves (laminitis). This hindgut to hoof link might seem mysterious, but science has revealed the critical pathways linking hindgut acidosis to laminitis.
Understanding this process begins with recognising how horses digest different carbohydrates. Horses evolved to process primarily fibrous plant material, with limited capacity for digesting large amounts of sugars, starches, and fructans – the types of carbohydrates abundant in lush spring grass and grain-based feeds.
The Sugar Surge and How Carbohydrates Trigger Trouble
Grasses and cereals store energy as complex carbohydrates, primarily fructans in grass and starch in grains. While horses can digest limited amounts of starch in the small intestine, they lack the enzymes needed to break down fructans. When horses consume excessive amounts of either carbohydrate, the undigested portions pass into the hindgut.
“When excessive starch or fructans reach the hindgut, they’re rapidly fermented by certain bacteria, particularly Equine Hindgut Streptococcal Species (EHSS),” explains Lisa Elliott, MSc. “Research has definitively linked these bacteria to laminitis onset.”
This rapid fermentation produces large amounts of lactic acid, dramatically lowering hindgut pH and creating acidosis. As pH drops, several critical changes occur:
1. Beneficial fibre-fermenting bacteria die off, releasing endotoxins
2. Microbial diversity decreases significantly
3. The gut lining becomes inflamed and more permeable
4. Bacterial toxins (lipopolysaccharides or LPS) leak into the bloodstream
5. Systemic inflammation develops, ultimately affecting the laminae in the hooves
This process results in what veterinarians call Sepsis Related Laminitis (SRL). This is a particularly dangerous form of the condition that can develop rapidly.
The Spring Grass Danger
Spring presents a perfect storm of conditions for laminitis development. Research has shown that some horses and ponies can consume up to 5% of their body weight in grass dry matter daily – that’s an astonishing amount! When this grass contains high levels of fructans, as spring grass often does, horses can easily consume enough to trigger hindgut acidosis.
Recent studies have uncovered another concerning factor: some horses have bacteria in their small intestine capable of breaking down fructans into fructose. This means fructan fermentation can begin before reaching the hindgut, potentially accelerating and intensifying the acidosis process.
The risk is particularly high when:
- Grass is growing rapidly after rain
- Days are sunny but nights remain cool
- Grass has been stressed by drought, frost, or overgrazing
- Horses have limited access to grass and gorge when turned out
- Horses or ponies are already insulin resistant or have a history of laminitis
For susceptible horses, these conditions create a dangerous scenario where hindgut acidosis can develop quickly, potentially leading to painful laminitis within hours or days.
In our final article of this series, we’ll explore practical strategies for preventing hindgut acidosis and supporting optimal microbiome health, including specific dietary recommendations and management practices to protect your horse during high-risk periods.
For immediate support in managing laminitis risk, consider our specially formulated LAMIGONE feed and supplementing the diet with Coligone Liquid, Fed together, they are designed to support horses prone to or recovering from laminitis. Contact our team at 0333 0503785/07986 183616 or email sales@hbradshaws.co.uk for personalised advice.
