How to Feed a Skinny Horse: Your Practical Guide to Weight Gain

Last updated: May 3, 2025

By: Miles HenryFact Checked

If you’ve ever stood in your barn aisle, frustration mounting as your horse’s ribs become a little too prominent, you’re not alone. I’ve been there, too. At a roping competition in Fort Worth, surrounded by seasoned horsemen, I was desperate for answers. My mare was losing weight despite everything I tried.

What I learned that day, and in the months that followed, is that feeding a skinny horse isn’t just about piling on calories. It’s a nuanced, individualized process—one that depends on the right nutrition at the right time.

This guide is for horse owners who want practical, science-backed solutions to help their underweight equine athletes regain condition and thrive. We’ll break down the essentials of a smart weight-gain program, blending expert insights with real-life experience—because I know what it’s like to face this challenge head-on.

💡 Curious how she looks now? Scroll down to see her transformation after three months of targeted feeding and digestive support.

What to Feed a Skinny Horse: Practical Strategies for Weight Gain

Effectively feeding a skinny horse is about more than just adding calories—it’s about understanding their individual needs, digestive health, and metabolic demands. Below are proven strategies backed by both experience and equine science to help your underweight horse regain condition.

Quick Reference: Best Feed Options for Skinny Horses

Feed Type	Key Benefit	Use Tip
Alicia Bermuda	Palatable, easy-to-digest grass hay	Feed free-choice; great base forage
Alfalfa	High protein and calorie-dense	Use to supplement grass hay (not as sole forage)
Beet Pulp	Digestible fiber, low starch	Soak before feeding; great for gut health
Rice Bran	High fat, antioxidant-rich	Introduce gradually over 1–2 weeks
DAC DDA	Supports gut health and nutrient uptake	Use with vet guidance, especially after stress or GI upset

🐴 Click each section below to expand practical tips.

Forage is the cornerstone of every healthy equine diet—and especially critical for weight gain. It fuels gut health, maintains digestive rhythm, and provides the bulk of a horse’s daily calories. Here’s how to get it right from the start.

🌾 Forage First: Laying the Foundation

Forage should make up the majority of your horse’s diet—ideally 1.5% to 2.5% of their body weight in hay or pasture daily. Without sufficient forage, the hindgut can’t function optimally, which can hinder digestion and weight gain.

• Grass Hay (Alicia Bermuda, Timothy, Orchardgrass):
  Highly digestible and easy on the gut, grass hay should form the base of the diet. When I switched my mare from high volumes of alfalfa to free-choice Alicia Bermuda, she began to regain weight and her digestion improved noticeably.
• Alfalfa – Use With Purpose:
  Alfalfa is rich in calories and protein and can be very useful for weight gain. But overuse can lead to imbalances or digestive discomfort. Use it as a supplement alongside grass hay—not the sole forage source. Read more about the pros and cons of alfalfa hay here.
• Feeding Tip:
  Always feed hay before grain. This stimulates saliva, buffers stomach acid, and reduces the risk of ulcers.

🔗 Learn more: Best Practices for Feeding Hay

When forage alone isn’t cutting it, concentrates and commercial feeds can fill the calorie gap—if used wisely. These feeds pack a punch, but they must be introduced strategically to avoid digestive upset or metabolic stress. Let’s break it down.

🧪 Concentrates & Commercial Feeds: Use with Care

When forage isn’t enough to meet calorie needs, especially in performance horses or seniors, concentrates can help—but must be introduced with care.

Grains in Moderation:
Oats, processed corn, and barley can add calories but should never replace forage. Introduce slowly, feed in small portions, and watch for digestive sensitivity.

Senior Feeds:
These are formulated for older horses with compromised digestion and often include beet pulp, added fat, and prebiotics. Learn more in our feeding guide for older horses.
→ Research supports this approach: older horses often have reduced digestive efficiency (Ireland et al., 2012; Brosnahan & Paradis, 2003).

Performance Feeds:
For active horses, choose calorie-dense formulas with 10–12% fat and 12–14% protein. These are specifically designed for energy replenishment and muscle development. Explore options in our racehorse nutrition guide.

Fiber plays a critical role in helping horses gain weight safely by fueling fermentation and improving gut health. Here’s how to use it strategically.

🌿 Add Digestible Fiber for Gut-Friendly Calories

Highly digestible fiber supports healthy weight gain by enhancing fermentation in the hindgut—providing slow-release energy and improving gut health.

Soy Hulls and Hay Pellets:
These fiber sources are palatable and easy to digest—great for horses with poor teeth or picky appetites.

Beet Pulp:
This super fiber is almost as calorie-dense as oats and is safe for horses with metabolic conditions or ulcers. It’s also beneficial for hydration and digestion. Always soak beet pulp before feeding to avoid choke.
→ Learn more in our guide: Feeding Beet Pulp to Horses—The Good and the Bad

Fat is the most energy-dense nutrient in a horse’s diet—providing over twice the calories of carbohydrates. Adding fat is a smart, low-volume way to increase intake, support endurance, and reduce digestive strain. Here’s how to use it effectively.

🥥 Add Fat for Efficient Calorie Loading

Fat contains 2.25x more energy per pound than carbohydrates, making it an ideal addition when trying to help a horse gain weight without increasing feed volume drastically.

Recommended fat sources:

• Stabilized Rice Bran: High in fat, fiber, and vitamin E—great for energy and antioxidant support.
• Flaxseed or Flax Oil: Adds omega-3s for coat and anti-inflammatory benefits.
• Corn Oil: Calorie-dense and affordable, though less balanced in fatty acids.
• Coconut Meal: Tasty, medium-chain triglycerides for quick, digestible energy.

⚠️ Introduce fat supplements gradually over 7–14 days to avoid digestive upset.

No matter how good your feed program is, it won’t matter if your horse can’t absorb the nutrients. Supporting gut health is essential for consistent weight gain, especially in stressed, aging, or recovering horses. Explore the top tools that make digestion more efficient.

🦠 Gut Health: Probiotics, Enzymes & More

Digestive health is a cornerstone of effective weight gain. Without proper gut function, your horse may not absorb the nutrients you’re feeding.

Probiotics & Prebiotics

These boost the gut microbiome, enhance fiber fermentation, and support immune function. I noticed real change in my mare when we added a probiotic and DAC Digestive Feed Additive (DDA) to her regimen. I may earn a small commission if you purchase through this link.

Digestive Enzymes

Help break down nutrients for better absorption—especially useful for senior or recovering horses.

Bonus Tip: Collaborate with Your Vet

Your veterinarian isn’t just for emergencies. Involving them early in your horse’s weight gain journey helps rule out underlying disease, develop custom feed plans, and ensure long-term success.

Research-backed insight: Digestive issues can significantly impair intake and utilization of nutrients. Dental problems, for instance, have been shown to reduce feed intake and increase fiber loss in manure (Zwirglmaier et al., 2011; Di Fillipo et al., 2018).

💡 Feeding right is essential, but uncovering the reason for weight loss is just as important. Now that your feeding plan is dialed in, it’s time to ask the deeper question: why was your horse losing weight in the first place?

Understanding the Root Cause: Why Won’t My Horse Gain Weight?

Before diving into what to feed a skinny horse, it’s essential to explore why they’re underweight in the first place. Simply adding more calories won’t help if underlying issues are left unaddressed. Here are the key factors, broken down into two categories for clarity:

Health-Related Causes

Dental Issues

Poor dental health—including sharp points, uneven wear, or equine odontoclastic tooth resorption and hypercementosis (EOTRH)—can severely impact a horse’s ability to chew and digest feed properly. Research shows that dental correction improves hay intake and digestibility.
→ Rehrl et al., 2018 – PubMed

Parasite Burden

Internal parasites can rob your horse of nutrients, even with a well-balanced diet. Worse, resistance to common dewormers is on the rise.
→ Fecal egg count testing and rotational strategies are now essential.
→ Kaplan, 2004 – Penn State Extension

Gastrointestinal Health

Ulcers, hindgut acidosis, and microbial imbalance can all suppress appetite and cause digestive problems for horses. This is especially common in high-stress environments or performance horses.
→ Nadeau et al., 2000 – AVMA Journal

Chronic Illness & Aging

As horses age, their digestive efficiency declines. Geriatric horses may also suffer from metabolic disorders or chronic inflammatory issues.
→ Ireland et al., 2012 – PubMed
→ A retrospective study by Tamzali (2006) documented chronic weight loss syndrome in 60 horses, reinforcing the importance of thorough diagnostics.

Environmental & Nutritional Issues

Social Stress & Herd Dynamics

Submissive horses may be pushed away from feed by dominant herd mates, leading to chronic underfeeding. Studies show that herd hierarchy significantly influences body condition.
→ Giles et al., 2015 – Applied Animal Behaviour Science
→ Christensen et al., 2011 – Applied Animal Behaviour Science

Inadequate Diet

Sometimes, the problem is simpler: the horse isn’t receiving enough calories—or the right balance of nutrients. This is common in performance horses, where calorie demands are high and feed may be forage-deficient.
→ Read more: Feeding Performance Horses – Nutrition Guide

Want to Learn More?

For an expanded look at these root causes, check out our full guide:
🔗 Why Is My Horse Losing Weight?

And for science-backed guidance, visit:
🔗 University of Minnesota Equine Extension – Caring for the Underweight Horse

Assessing Your Starting Point: Body Condition Scoring

Before starting a weight gain plan, it’s essential to assess your horse’s current condition. The Henneke Body Condition Scoring System is the gold standard for objectively evaluating a horse’s fat reserves. It uses a scale from 1 (emaciated) to 9 (obese), with a score of 4 to 5 considered ideal for most horses.

This system evaluates fat deposits in six key areas: along the neck, withers, loin, tailhead, ribs, and shoulder. A score below 4 typically indicates the need for dietary intervention.

Recommended Tools to Help You Score Accurately:

• Purdue Extension PDF
  This guide offers a comprehensive explanation of the Henneke scoring method, making it ideal for horse owners who want to delve into the science and methodology behind the numbers.
• DEFHR Illustrated Guide
  This visual guide is ideal for quick reference and for those who are visual learners. It shows photographic examples of each score, making it easier to identify your horse’s condition in the field.

👉 Pro Tip: Print the DEFHR guide and keep it in your barn for easy monthly check-ins.

The relationship between condition score and body fat percentage has been well-documented in research. Monitoring this score monthly allows you to track progress and adjust your feeding plan accordingly.

Monitoring Progress and Feeding Strategy

To help your underweight horse safely gain weight, consistency and close monitoring are key. Here’s how to track improvement and optimize feeding patterns:

🐴 1. Feed Consistently and Frequently

• Offer 3–4 small meals per day instead of one or two large ones. This mirrors natural grazing behavior and supports steady digestion.
• Never leave your horse without forage for more than 4 hours—an empty stomach can disrupt gut health and lead to ulcers.
• Maintain a regular feeding schedule to support metabolic balance and routine.

📏 2. Track Body Condition Over Time

• Body Condition Scoring (BCS): Use the Henneke scale monthly to assess fat cover and muscle development. Scores below 4 often require intervention.
• Weight Taping: Measure weekly. A gain of 0.5 to 1 lb/day is ideal but can vary by individual.
• Visual Check-Ins: Watch for improved coat shine, muscle tone, and alertness in addition to numeric scores.

💩 3. Use Manure as a Health Indicator

• Look for changes in fiber length or consistency. Long, undigested fibers may indicate poor chewing or dental issues.
• Sudden changes (soft stools, overly dry manure) may suggest feed intolerance or digestive imbalance.

Estimating Feed Quantities

While individual needs vary, here’s a general guideline for how to help a skinny racehorse gain weight:

Horse Weight (lbs)	Daily Hay (lbs)	Daily Concentrate (lbs)	Notes
1,000	20-25	4-6	Adjust based on BCS and activity level. Add fat/fiber as needed.
1,200	24-30	4.8-7.2	Monitor closely and adjust based on progress.

Note: This is a general guideline. Constantly adjust based on your horse’s individual body condition score, activity level, and the specific nutrient content of your feeds. Consulting with an equine nutritionist is highly recommended for a tailored feeding plan.

Common Pitfalls to Avoid When Trying to Feed a Skinny Horse:

Learning what not to do is just as important as knowing what to do:

🛑 Abrupt Feed Changes

Rapid shifts can cause digestive upset, colic, or diarrhea. Always transition feeds slowly over 7–10 days.

🌾 Grain Overload

Grains provide calories but can upset gut health and increase laminitis risk. Prioritize forage and balance carefully.
🔗 Learn about laminitis prevention

🦷 Dental Neglect

Undiagnosed dental issues like EOTRH reduce intake and cause poor digestion. Schedule regular exams.

🐴 Ignoring Herd Dynamics

Submissive horses may get pushed away from food. Observe feeding behavior and adjust turnout strategies.

🧬 Unaddressed Health Problems

Chronic weight loss may signal deeper health issues. Work with your vet to rule these out .

⏰ Inconsistent Feeding Times

Horses thrive on routine. Unpredictable feeding can cause stress and reduce nutrient absorption.

Avoiding these common pitfalls can make the difference between frustration and steady progress. The good news? Most are easy to correct with consistency and attention to detail. But if progress still stalls despite your best efforts, it’s time to bring in professional guidance.

When to Enlist Professional Help:

If you’ve implemented dietary changes and your horse is still struggling to gain weight, it’s time to call in the experts:

• Schedule a Thorough Dental Exam: A veterinarian specializing in equine dentistry can identify and address any underlying dental issues.
• Run Comprehensive Fecal Tests: To accurately assess and manage parasite loads. Remember that relying solely on calendar-based deworming may not be effective due to increasing drug resistance (Kaplan, 2004; McFarlane et al., 2010).
• Consult an Equine Nutritionist: A qualified nutritionist can develop a personalized feeding plan tailored to your horse’s specific needs, activity level, and any underlying health conditions. They can also help you balance micronutrients and optimize your feeding strategy for weight gain.

Frequently Asked Questions About Feeding Skinny Horses

Got questions about helping your underweight horse? These expert-backed answers cover the most common concerns, from what to feed to when to call the vet.

Final Thoughts: A Journey of Observation and Adaptation

🐎 Your horse’s weight gain journey is a marathon, not a sprint. Stay consistent, measure often, and always adapt as needed.

Have you faced a challenge feeding a skinny horse? Drop your story in the comments—we’d love to learn from your experience.