Is Your Horse Predisposed to Insulin-Related Laminitis? 2025 Vet Guide to Risk Factors, Breeds & Prevention 🧬🐴

By Dr Duncan Houston, BVSc

Introduction

Laminitis is one of the most painful and debilitating hoof conditions in horses. In 2025, the leading cause of laminitis is no longer grain overload or mechanical stress—it’s insulin dysregulation. Known as insulin-related or hyperinsulinemia-associated laminitis, this condition occurs when your horse’s body produces too much insulin in response to sugars and starches, damaging blood flow to the hoof. Early identification and management can prevent this condition from becoming life-threatening.

What Is Insulin-Related Laminitis? ⚠️

• Caused by elevated insulin levels in the bloodstream
• Part of Equine Metabolic Syndrome (EMS)
• Insulin damages the laminae, the sensitive tissues bonding the hoof wall to the bone
• Triggers inflammation, pain, and separation of the hoof capsule

Who Is at Risk? 🧬

1. Obese Horses

• Cresty neck or fat pads over the ribs, shoulders, and tailhead
• Obesity worsens insulin resistance, triggering laminitis

2. Certain Breeds

• Ponies – especially native or hardy types
• Warmbloods
• Spanish breeds – Andalusians, Lusitanos
• Gaited horses – Tennessee Walking Horses, Paso Finos
• Miniature horses

3. Horses with Genetic Predisposition

• Some horses are genetically programmed to be more metabolically efficient
• They evolved to survive in harsh, low-forage environments
• Modern lush pastures and sweet feeds overwhelm their metabolism

4. Horses with Regional Fat Deposits

• Even if not obese overall, fat deposits on:
  • Crest of the neck
  • Tailhead
  • Shoulders or behind elbows
• These horses may still be insulin-resistant

Understanding Equine Metabolic Syndrome (EMS) 🧠

• EMS is a cluster of symptoms including:
  • Insulin resistance (hyperinsulinemia)
  • Obesity or abnormal fat distribution
  • High risk of laminitis
• Triggered by:
  • High-sugar pastures
  • High-starch feeds
  • Stress or illness

How Insulin Causes Laminitis 🔬

• High blood insulin causes vasoconstriction in the hoof
• This reduces blood flow and nutrient delivery
• The laminae weaken and separate, causing rotation or sinking of the pedal bone

Diagnosis 🩺

• Fasting insulin tests
• Oral sugar test (OST) to measure insulin spikes
• Radiographs of hooves to check for rotation or inflammation
• BCS (Body Condition Scoring) to identify fat distribution

Prevention & Management 🌱

1. Weight Control

• Feed 1.5–2% of ideal body weight in forage
• Use slow feeders or hay nets to prolong feeding
• Exercise daily to improve insulin sensitivity

2. Test and Limit Forage NSC (Non-Structural Carbohydrates)

• NSC = sugars + starch
• Feed hay with NSC below 10% for insulin-resistant horses
• Soak hay in cold water for 30–60 minutes to lower sugars

3. Avoid Pasture Access During High-Sugar Times

• Spring and fall grass is highest in sugar
• Pasture NSC peaks in early morning and late afternoon
• Use a dry lot or restrict turnout using grazing muzzles

4. Use Low-Sugar, Low-Starch Feeds

• Choose forage-based, low-carb concentrates
• Avoid molasses, corn, oats, or sweet feeds

Case Example: Laminitic Pony on Lush Grass

1. 12-year-old Welsh pony developed sudden lameness
2. Radiographs showed mild rotation; insulin 4x normal range
3. Pony moved to dry lot with soaked hay and no grain
4. Supplemented with magnesium and chromium
5. After 3 months, insulin normalized and hooves stabilized

FAQs About Insulin-Related Laminitis

Q: Can my horse have laminitis without being obese?

A: Yes. Fat deposits on the neck, shoulders, or tailhead may signal risk even if the horse appears lean.

Q: Can I just mow the grass to reduce sugar?

A: No. Mowing may not reduce NSC enough to protect sensitive horses. Use tested hay and dry lots instead.

Q: What’s the best supplement for insulin regulation?

A: Magnesium, chromium, and cinnamon extract may help—but always consult your vet first.

Conclusion

Insulin-related laminitis is the leading cause of hoof pain in modern horses—but it’s largely preventable. In 2025, proactive care, smart feeding, and early detection can make all the difference. If your horse is a susceptible breed or shows signs of fat accumulation, it's time to get serious about metabolic monitoring.

Need help managing your horse’s diet or insulin status? Visit AskAVet.com or download our app 📱 to get expert help from Dr Duncan Houston on preventing and managing laminitis. 🩺🐴