How to Reverse Under-Run Heels with Trim and Tools?

Under-run heels—also called underslung heels—occur when the horse’s heel grows forward and collapses under the hoof, instead of maintaining a more upright position at the back. This conformation flaw alters the hoof-pastern axis, shortens the horse’s stride, and can lead to chronic lameness if neglected. Fortunately, reversing under-run heels is possible through a careful blend of precise trimming strategies, supportive tools, and consistent maintenance.

In this guide, we’ll explore what causes under-run heels, how to identify them, and the step-by-step approach to restoring healthier angles using must-have farrier tools. Whether you’re a horse owner aiming to improve your horse’s soundness or a farrier refining your craft, these insights will help you manage and gradually correct under-run heels.

1. Understanding Under-Run Heels

Under-run heels occur when the heel tubules are angled forward (toward the toe) instead of growing more upright under the horse’s weight-bearing structure. As a result, the horse’s heel effectively “runs forward,” leading to:

1. Low, Collapsed Heels

   • The back of the hoof appears flatter, with insufficient height or support for the horse’s weight.

2. Excessive Toe Length

   • Because the heel is pulled forward, the toe often looks relatively long, adding leverage forces to the hoof.

3. Altered Weight Distribution

   • The horse may load the toe excessively, increasing strain on the deep digital flexor tendon and distal limb joints.

Common Causes

• Genetics: Some horses inherit hoof shapes that trend toward underslung heels.

• Infrequent or Imbalanced Trimming: Allowing heels to grow unchecked or rasping them aggressively without addressing toe length.

• Excessive Moisture/Environment: Constantly wet footing can soften the hoof, encouraging heel collapse.

• Performance Stress: Horses in high-impact disciplines can gradually deform their heels if not managed with regular farrier care.

2. Why Correcting Under-Run Heels Matters

1. Prevent Lameness

   • Overly forward heels place undue stress on tendons and joints, eventually leading to pain or chronic lameness.

2. Improve Gait and Performance

   • Balanced hooves allow a smoother, more efficient stride. Horses with corrected heel angles move more confidently and comfortably.

3. Long-Term Hoof Health

   • Addressing under-run heels reduces the risk of collateral hoof problems like quarter cracks, sole bruising, or joint inflammation.

3. Essential Farrier Tools for Under-Run Heel Correction

3.1 Hoof Pick

Purpose: Clearing debris from the sole, frog, and heel area.

• Why It’s Key:

  • Accurate Assessment: A clean hoof reveals how far the heels have collapsed.

  • Daily Maintenance: Regular picking can catch early signs of distortion or infection that worsen under-run heels.

3.2 Hoof Gauge

Purpose: Measuring hoof angle relative to the pastern.

• Why It’s Key:

  • Baseline Data: Identifies the degree of heel collapse.

  • Progress Tracking: Frequent measurements help you see if your trimming strategy is improving heel angles over time.

3.3 Hoof Nippers

Purpose: Cutting away excess hoof wall, especially if the toe is elongated.

• Why It’s Key:

  • Reducing Toe Leverage: Shortening an overly long toe is crucial for letting the heels de-stress and regrow more upright.

  • Gradual Heel Adjustments: Nippers remove small amounts of overgrown heel tubules.

3.4 Farrier’s Rasp

Purpose: Smoothing and shaping the trimmed hoof.

• Why It’s Key:

  • Refine Angles: After nipping, a rasp ensures a balanced transition from toe to heel.

  • Eliminate Flares: Under-run heels often come with side flares that exacerbate imbalances. A rasp can correct these gently.

3.5 Specialty Shoes or Pads

Purpose: Correcting or mitigating excessive strain on the heels.

• Why It’s Key:

  • Lifting and Supporting: Wedge pads or bar shoes can encourage the heels to regrow at a healthier angle, reducing ongoing stress.

  • Protection: Specialized shoes prevent rapid wear of newly regrown heel structures.

3.6 Hoof Knife

Purpose: Paring away dead sole or ragged frog tissue.

• Why It’s Key:

  • Define Trim Boundaries: Ensures you know where healthy sole begins, so you don’t over-trim the heel.

  • Clear the Heel Seat: Removing debris or overgrown frog around the heel seat helps you see the true level of heel growth.

4. Step-by-Step: Reversing Under-Run Heels with Trim and Tools

Step 1: Assess and Clean

1. Hoof Pick

   • Remove dirt and rocks. Examine the sole and frog, noting any uneven wear or cracks.

2. Hoof Gauge

   • Measure the current hoof angle, focusing on the heel’s alignment relative to the pastern. Record these numbers for future comparison.

Pro Tip: Notice if the horse’s stance indicates toe-loading. A pronounced forward posture might confirm severely under-run heels.

Step 2: Reduce Toe Leverage

1. Use Hoof Nippers

   • Carefully shorten the toe if it’s excessively long. Removing toe length helps relieve pulling forces on the heels.

2. Apply Farrier’s Rasp

   • Smooth out the toe and any flares. Ensure the dorsal (front) hoof wall is aligned with the pastern angle to some degree, but avoid removing too much at once.

Pro Tip: Overly aggressive toe removal can cause soreness or accelerate coffin bone stress. Aim for moderate changes per trimming cycle (every 4–6 weeks, if needed).

Step 3: Address Heel Height

1. Check Heel Orientation

   • Identify how far forward the heel tubules are angled. Compare medial (inside) vs. lateral (outside) heights.

2. Trim Conservatively

   • Use nippers or a rasp to remove only the necessary amount. Quick, drastic heel reductions can strain tendons and ligaments.

3. Balance Heel to Sole Plane

   • The goal is to establish a heel height that meets the natural arch of the sole, while guiding the tubules to grow more upright over successive trims.

Pro Tip: If you drastically lower a collapsed heel in one session, the horse can become lame from sudden changes in limb alignment. Gradual improvement is safer.

Step 4: Consider Supportive Shoes or Pads

1. Evaluate Shoeing Options

   • Discuss with a farrier whether a bar shoe, wedge pad, or other supportive shoe design will help the horse maintain corrected angles.

2. Fit Shoes Carefully

   • The shoe’s length should fully support the end of the heel. Undersized shoes can worsen the problem by letting the heel “run” forward unchecked.

3. Periodically Check Fit

   • If wedge pads are used, monitor the hoof’s response. Some horses adapt quickly; others may need progressive adjustments over multiple farrier visits.

Step 5: Monitor and Adjust

1. Re-Measure with Hoof Gauge

   • Each trimming cycle, compare angles to your initial baseline. Small improvements add up over time.

2. Frequent Trimming Cycle

   • Horses with under-run heels often benefit from slightly shorter intervals, like 4–6 weeks, maintaining the gains from each trim.

3. Assess Movement

   • Watch for improved heel-first landings, reduced toe scuffing, and a more relaxed stride.

5. Maintaining Progress and Preventing Relapse

1. Balanced Nutrition

   • Adequate biotin, zinc, and amino acids foster stronger hoof horn and healthier heel growth.

2. Moderate Exercise

   • Consistent, controlled movement on good footing encourages better circulation in the hoof, aiding structural integrity.

3. Manage Environment

   • Avoid extreme wet-dry cycles that weaken hoof walls. Clean, dry bedding and stable turnout conditions help preserve the newly regained heel shape.

4. Regular Check-Ups

   • Early detection of re-collapsing heels can prevent a major setback. Catch small changes before they require large corrections.

6. Frequently Asked Questions (FAQ)

Q1: Can under-run heels be permanently fixed?

Many horses show remarkable improvements, though some may always need careful maintenance to keep the heels from reverting. Consistency in trimming and shoeing is key.

Q2: How quickly should I expect to see results?

Progress is gradual. You might see noticeable changes in a few trimming cycles (3–6 months), but true structural improvements typically take closer to a year, as the hoof grows out.

Q3: Do I need special shoes for mild under-run heels?

Not always. If the horse is comfortable and changes are moderate, a skilled farrier can manage with trimming alone. Severe cases often benefit from supportive or corrective shoeing.

Q4: Are there any risks to trimming the heels too aggressively?

Yes. Over-trimming can cause soreness, tendon strain, or even lead to a negative palmar angle (where the coffin bone tilts too far downward). Slow, steady change is safer.

Q5: What about barefoot horses with under-run heels?

Barefoot horses can still improve with frequent, precise trims and balanced nutrition. You may also consider hoof boots for protection if the horse is tender during transitions.

Q6: Could conformation issues cause recurring under-run heels?

Yes, conformation plays a role. Some horses with upright pasterns or other structural factors require ongoing trimming adjustments to maintain normal heel angles.

7. Call-to-Action

Tackling under-run heels doesn’t have to be daunting. With the right trimming methods and essential farrier tools—hoof pick, nippers, rasps, hoof gauge, and, when needed, supportive shoes or pads—you can guide your horse’s heels back to a healthier angle. Work closely with a trusted farrier for a personalized plan, maintain a consistent trimming schedule, and keep an eye on environmental factors that affect hoof growth. Over time, you’ll see improved stride comfort, better hoof integrity, and a happier, more sound horse.

Final Thoughts

Under-run heels are a manageable but potentially serious hoof challenge that demands a patient, methodical approach. By integrating careful trimming, toe leverage reduction, and supportive measures, you can gradually realign the horse’s hoof angles, relieving undue stress on the limbs. With diligence, proper tools, and professional guidance, even longstanding cases of under-run heels can improve significantly, giving your horse the foundation it needs for lasting health and peak performance.