🐴 Change Your Horse’s Diet Slowly: Protect Digestive Health in 2025 🥕⚖️

By Dr Duncan Houston BVSc

In 2025, horse owners continue to learn that abrupt diet changes can lead to serious health issues—including colic, laminitis, and endotoxemia. Whether you're switching hay, grain, or introducing pasture, make transitions gradually to safeguard your horse’s sensitive digestive system. 🧠🐎

📉 Why Changing Feed Can Be Dangerous

Unlike some animals, a horse’s gut relies heavily on a balanced community of microorganisms in the hindgut. These microbes digest fiber and help process carbohydrates, protein, and more. 🦠

Each feed type supports different microbial populations—so when you abruptly change feed:

• 💥 Bacteria die off
• ☠️ Toxins are released
• 💉 Toxins enter the bloodstream
• ⚠️ Colic, laminitis, and endotoxemia can follow

🔬 Research That Proves It

A New Zealand study monitored two groups of fillies—six on pasture and six on silage. After switching the silage group to pasture:

• 🔬 The microbiome took 4 full days to adapt to the new forage
• 📉 During this time, risk of GI upset was elevated

This reinforces the need for multi-day transitions even between forages. ✅

📆 Safe Feed Transition Timeline

Recommended Schedule:

• 🗓️ Mix new and old feed for 10 to 14 days
• 📈 Gradually increase new feed by 10–25% every 2–3 days

This applies to:

• 🥕 Grain or pelleted feeds
• 🌾 Hay types (e.g., alfalfa to bermuda)
• 🌱 Introducing new pasture

🌱 How to Transition to Pasture

Even lush spring grass should be introduced slowly:

• 🌅 Start with 30 minutes per day
• 🕒 Add 15–30 minutes daily if tolerated
• ⛑️ Use a grazing muzzle for insulin-resistant or overweight horses

Pasture grass can be high in non-structural carbohydrates (NSCs) and may spike insulin and sugar levels. 🧬

🧠 Common Mistakes to Avoid

• 🚫 Running out of feed and switching brands suddenly
• 🚫 Assuming hay is "just hay"—even bale-to-bale variation matters
• 🚫 Moving from dry lot to full pasture turnout in one day

📝 Pro Tips

• 📦 Always keep a small backup supply of your current feed
• 📊 Track your transition plan using a feed chart
• 🧪 Consider hay testing for NSC content

📲 Ask A Vet for Feeding Transition Plans

Not sure how to change your horse’s diet? Visit AskAVet.com or use the Ask A Vet App to get customized feed swap schedules and risk assessments. 📱🐴

Dr Duncan Houston and the team can help you reduce the risk of GI problems by designing safe, science-backed transition plans. 💬🧠

🏁 Final Thoughts

In 2025, we know that slow and steady wins the race when it comes to feed changes. Avoid sudden diet shifts, monitor your horse, and protect their gut. 🐴❤️

Need a printable feed transition tracker? Visit AskAVet.com to download yours 🐎🥕