Putting Weight on a Skinny Horse: Vet Insights for 2025 from Dr Duncan Houston 🐴🌿

By Dr Duncan Houston, BVSc

Helping a thin horse reach a healthy weight can be just as challenging as trying to slim down an overweight one. In 2025, equine nutrition and veterinary science provide us better tools and knowledge than ever before. This comprehensive guide, crafted by veterinary expert Dr Duncan Houston, will walk you through **everything you need** to help your horse gain weight safely and effectively.

1. Why Is My Horse So Skinny? 🤔

Many horse owners are surprised to learn that a horse’s weight loss often stems from underlying issues rather than lack of food. Common causes include:

• 📌 Parasites: Worm burdens steal nutrients and cause weight loss.
• 📌 Dental problems: Worn, infected, or misaligned teeth prevent proper chewing and digestion.
• 📌 Chronic infections or illness: Conditions like pneumonia or low-grade infections increase energy needs.
• 📌 Cancer or organ disease: Such as liver issues, which impair nutrient absorption.
• 📌 Poor quality feed: Low-energy hay, dust, mold, or weathered pasture.

Before changing dietary strategies, Dr Duncan Houston recommends a full veterinary check-up to identify possible health concerns.

2. Assessing Body Condition 📏

The Body Condition Score (BCS) is a key tool in monitoring your horse’s weight progress. The scale runs from 1 (emaciated) to 9 (obese). A score of 4–6 is ideal for most horses. Tools of the trade include:

• BCS chart referencing neck, shoulder, back, ribs, and tailhead fat deposits.
• Photographing your horse weekly for side-by-side comparison.

Track changes every 2–4 weeks and adjust feeding as needed.

3. Feed Strategies: Fiber, Starch & Fat 🔍

🍃 3.1 Fiber (Forage)

Forage is the foundation of any weight gain plan. High-quality hay and pasture provide the bulk of a horse’s diet:

• Choose early-cut grass hay with more leaves and less stem for digestible energy.
• Consider unlimited access to pasture, especially in spring and fall.
• Soaked beet pulp (no molasses) is a good source of digestible fiber.

Hard—or “hot”—keepers typically need 1.5–2% of their body weight in dry matter daily, so if your horse is 500 kg, that’s ~7.5–10 kg of forage.

🌾 3.2 Starch (Grains & Concentrates)

Grains are fiber’s calorie-boosting partner, supplying dense energy. Common options:

• Oats, barley, corn, commercially prepared grains.
• Feeding limit: max 0.5% of body weight per day (~2.5 kg for a 500 kg horse).
• Best given in multiple small meals to prevent colic or laminitis.

🧈 3.3 Fat

Fat is by far the safest and most efficient calorie source for overweight-prone horses:

• Vegetable oils (soy, rice bran, canola) added at 100–200 ml per feeding.
• Rice bran pellets: easy to feed and palatable—1–2 kg/day provides ~350–700 kcal.
• Cool calories = less sugar/starch, lower risk of feed-related laminitis.

4. Don’t Skip on Protein – Quality Matters 🧪

While protein isn’t a primary energy source, it’s vital for muscle growth and repair. Choose feeds containing:

• Alfalfa-based feeds or pellets: favourable amino acid balance.
• Commercial performance or breeding concentrates with 12–14% protein.

Dr Duncan Houston advises a balanced approach: “Protein supports muscle mass, but excess protein just wastes calories. Focus on total caloric intake first, then optimize protein.”

5. Supplements & Add‑Ons 🌟

Some supplements can enhance conditioning, but they’re not magic bullets:

• Probiotics/Prebiotics: Support gut health, boost nutrient absorption.
• Digestive enzymes: Assist older or low-digestibility hay.
• Vitamins/minerals: Especially biotin, zinc, selenium where hay is poor.
• Stay-thick supplements for gastric ulcers: Weight loss can mask discomfort from ulcers, which often reduce appetite.

6. Health Checks: Parasites, Dentals, Vaccines 🩺

• Fecal egg counts: Every 8–12 weeks, plus targeted worming.
• Dental care: Routine exams (every 6–12 months). Floating worn teeth improves chewing.
• Vaccinations: Support overall health; illness can rapidly cause weight loss.
• Bloodwork: Check liver, kidney, thyroid, pituitary (Cushing’s) if weight stalls.

7. Creating a Weight Gain Plan ✅

Step‑by‑Step Feeding Program

Below is a sample plan for a 500 kg hard-keeper (BCS 3/9→target 5/9):

1. Forage: 7.5–10 kg/day good-quality hay + unlimited pasture.
2. Fiber boost: add 2 kg soaked beet pulp.
3. Fat: 200 ml oil or 1 kg rice bran daily.
4. Concentrate: 1.5–2 kg grain mix divided twice daily.
5. Protein supplement: 1 kg alfalfa pellets or performance feed.
6. Supplements: probiotics, biotin, mineral mix per vet advice.
7. Health care: dentals, worming, vaccines, deworm – tracked and scheduled.
8. Monitoring: check BCS and weight every 2–4 weeks; adjust feeding accordingly.

8. Common Pitfalls to Avoid 🚫

• 🥖 Starch overload: Too much grain increases colic and laminitis risk.
• 🍼 Sudden feed changes: Transition supplements and hay slowly over 7–14 days.
• 🧂 Salt and water: Always provide free access—electrolyte loss from sweating worsens weight loss.
• 🐴 Lack of turnout: Exercise and movement improve digestion and appetite.

9. Special Considerations by Life Stage & Breed

Young and Aging Horses

Yearlings and seniors have unique needs:

• Weanlings: Higher protein, creep feeding, dental check.
• Seniors: Look for poor dentition, consider soaked or pelleted feeds and digestive aids.

Breed & Metabolic Types

Horses like Arabians or Thoroughbreds may need more concentrated feed, while ponies and drafts gain weight easily. Tailor energy sources accordingly.

10. When to Call the Vet 📞

Seek veterinary help if your horse shows:

• Rapid unexplained weight loss.
• Chronic diarrhea, fever, coughing, or nasal discharge.
• Signs of laminitis—reluctance to move, lameness, heat in the feet.
• Obvious dental problems or difficulty eating.

Early intervention often prevents major setbacks and improves outcomes.

11. Monitoring & Adjusting Progress

• Regular weigh-ins every 2–4 weeks.
• Photographic log with BCS notes.
• Adjust fat, grain, or forage intake as needed.
• If weight gain plateaus, re-evaluate all factors—health status, dental, worming, stress.

12. Real-Life Case: “Blaze” the Hard-Keeper

“Blaze,” a 12-year-old Thoroughbred-type, came in underweight with BCS 3/9. Under Dr Duncan Houston’s guidance, he went on a 4-month plan:

• Added 2 kg beet pulp, 1 kg rice bran, 2 kg performance grain.
• Dental float, Cushing’s bloodwork, targeted worming.
• By 16 weeks, scored BCS 5/9, bright coat, better stamina under saddle.

Blaze’s successful turnaround illustrates that targeted vet care + caloric strategy = sustainable weight gain.

13. Summary Table: Quick Reference

14. Final Thoughts from Dr Duncan Houston 💡

Weight gain in skinny horses isn’t about just feeding more—it’s about **feeding smart**. A holistic approach that combines veterinary care, balanced nutrition, consistent monitoring, and stress reduction can make all the difference. Hard-keeping horses need a built-in support system—you can set them up for success!

For personalized diet plans and ongoing support, visit AskAVet.com or download the Ask A Vet app📲—your partner in expert equine care.

– Dr Duncan Houston, BVSc