🐴 Digestion in Horses: How Equine GI Function Shapes Health in 2025 🔬🌾

By Dr Duncan Houston BVSc

Understanding how horses digest their food is key to preventing colic, ulcers, and laminitis. In 2025, we know more than ever about how a horse’s unique digestive anatomy demands natural grazing—not large grain meals. Let’s break down the equine gut and what that means for your feeding program. 🧠🐎

🔍 Comparing Digestive Systems

• 👨‍⚕️ Humans, dogs, and cats have a simple stomach
• 🐄 Cattle have a rumen for fermentation at the beginning of the digestive tract
• 🐴 Horses are , meaning their fermentation chamber—the cecum—is at the end of the GI tract

This means horses combine both systems: they digest protein, fat, and simple carbs in the small intestine, and ferment fiber in the cecum. 🔁

🥬 The Cecum: Nature’s Fermentation Vat

The cecum in horses functions similarly to the rumen in cattle. It allows for fermentation of fibrous materials like:

• 🌿 Grass
• 🌾 Hay
• 🍃 Other roughage

However, because it’s at the end of the digestive tract, nutrients from fermentation aren’t as readily absorbed as in ruminants. This makes digestive efficiency lower for high-starch diets. ❌

⏳ Natural Grazers, Not Meal Feeders

Horses were designed to graze continuously for 18+ hours a day. Modern feeding practices—two large meals of grain or hay—cause issues like:

• 💥 Colic
• 🔥 Gastric ulcers
• ⚠️ Founder (laminitis)

When horses go long periods without forage, stomach acid builds up, the gut slows down, and undigested sugars reach the cecum—a recipe for disaster. 🧪

🧪 Digestion in the Small Intestine

The small intestine is the main site for digestion of:

• 🍗 Protein
• 🥑 Fat (even though horses lack a gallbladder!)
• 🍬 Non-structural carbohydrates (NSCs)

Fat digestion is surprisingly efficient despite the lack of a gallbladder—bile flows directly from the liver. ✅

🚫 NSC Overload = Trouble in the Cecum

When too many NSCs (sugars, starches) are fed, the small intestine can’t digest them all. Excess starch moves to the cecum and is:

• ⚡ Rapidly fermented by bacteria
• ⬇️ Decreases cecal pH
• 💥 Kills off beneficial bacteria
• 🦠 Releases toxins that enter the bloodstream

This process triggers colic, endotoxemia, laminitis, and systemic inflammation. ⛔

✅ How to Support Healthy Digestion

• 🌾 Feed small, frequent forage-based meals
• 🚫 Minimize grain and high-NSC feeds
• 🚶 Maximize turnout and movement
• 💧 Ensure constant access to clean water

Let your horse eat like a horse—slow, steady, and fibrous. 🐴🌱

📲 Ask A Vet for Diet Design

Need help designing a gut-friendly feeding program? Visit AskAVet.com or use the Ask A Vet App for custom diet planning, NSC analysis, and colic prevention strategies. 📱🐴

Dr Duncan Houston and the team can evaluate your feeding schedule and forage quality to support long-term digestive health. 💬🧠

🏁 Final Thoughts

In 2025, the best way to prevent digestive issues in horses is to feed with their natural design in mind. Avoid starch overload, prioritize forage, and promote grazing behavior—not just big meals. 🐴❤️

Need a forage-first feeding plan? Visit AskAVet.com to get started 🐎🌾