Vet Advice: Feeding Horses with Pasture-Associated Laminitis 2025 🌱🐴🔥

By Dr Duncan Houston, BVSc

Pasture seems like the most natural feed for a horse—but for horses with insulin resistance, Equine Metabolic Syndrome (EMS), or Cushing’s disease (PPID), even lush green grass can be dangerous. 🌾💥

In fact, more horses develop laminitis from pasture-related carbohydrate overload than from grain feeding. In this 2025 veterinary guide, Dr Duncan Houston breaks down safe feeding strategies for managing horses at risk of pasture-associated laminitis. 🐎🧠

1. What Is Pasture-Associated Laminitis? 🩺🔥

Laminitis is the painful inflammation of the laminae in the horse’s hoof. It can lead to permanent structural damage and founder. Pasture-associated laminitis happens when high carbohydrate intake from grass triggers a hormonal or metabolic reaction. 🔥🐾

Horses most at risk include:

• 🍩 Easy keepers or overweight horses
• 🧬 Horses with EMS (Equine Metabolic Syndrome)
• 🧓 Horses with PPID (Cushing’s disease)

These horses often have impaired insulin regulation, which makes them more sensitive to sugar-rich forage. 📈

2. Why Grass Can Be Risky 🌾🍬

Pasture grass contains nonstructural carbohydrates (NSCs), including:

• 🍭 Fructans
• 🌿 Sugars
• 🍚 Starches

NSC content spikes during sunny weather and varies based on grass type and time of day. 🌤️

Key NSC facts:

• 🌄 Lowest in early morning (due to nighttime metabolism)
• 🌇 Highest in late afternoon (after full day of photosynthesis)

Letting a laminitic horse graze in the afternoon increases the risk significantly. ⛔

3. Grazing Time Restriction Doesn’t Always Work ⏱️

Some owners attempt to limit pasture time—but studies show that:

• 📉 Horses compensate by binge-grazing when given access
• ⏳ Only severe restriction (few minutes daily) effectively reduces intake

Tip: If you allow any grazing, limit it to early mornings and for only a few minutes. Better yet, consider a dry lot with hay testing under 10% NSC. 🐴🪵

4. Feeding Frequency and Insulin Control 🍽️🧪

A study from Ohio State University found that feeding smaller, more frequent meals reduces insulin spikes—important for laminitis-prone horses. 💉

Smart meal planning:

• 🕒 Feed 3–4 small hay meals per day
• 🌾 Choose hay with NSC below 10%
• 🧂 Add a ration balancer for missing minerals

Avoid: Large grain meals, molasses, high-NSC hays, and afternoon grazing. ⚠️

5. Safe Forage Options ✅

Best hay choices:

• 🌿 Mature Bermuda grass hay
• 🌾 Late-cut timothy (tested)
• 🧪 Soaked hay (30–60 min) to reduce sugars

Forage to avoid:

• 🍚 Alfalfa (may be too rich in some horses)
• 🌞 Spring pasture grass
• 🥕 Sugary treats or beet pulp with molasses

Test hay if possible or buy from dealers who do. 🧪📦

6. Use Grazing Muzzles for Control 😷🌱

Grazing muzzles reduce intake by up to 80%. They're ideal for:

• 🐴 Easy keepers
• 🍃 Horses on limited turnout
• ⏱️ Short-term controlled grazing sessions

Be sure to fit properly, monitor for rubs, and remove during meals. 🧼

7. Summary Table: Laminitis-Safe Feeding Plan 📋✅

8. Final Thoughts from Dr Duncan Houston 💬

Pasture-associated laminitis is preventable with smart grazing and feeding strategies. Know your horse’s risk factors, test hay, and avoid peak-carb grazing times. Feeding smaller, low-NSC meals and limiting pasture exposure can make all the difference. 🧠🐴🌿

Need help creating a safe feed plan for your laminitis-prone horse? Visit AskAVet.com or download the Ask A Vet app 📲 for 24/7 support from trusted equine nutrition and veterinary experts.

— Dr Duncan Houston, BVSc