Hoof trimming protocols for laminitis – a review

Introduction to Hoof Trimming Protocols in Laminitis Treatment

Laminitis is a complex, multifactorial disease, and one of its most concerning consequences is the rotation of the coffin bone (P3) relative to the second phalanx (P2) due to laminar failure. Trimming protocols are widely debated among practitioners as to whether they can prevent or reduce P3 rotation and help manage the laminitis progression. The goal of trimming in laminitis cases is to stabilize P3 within the hoof capsule, reduce mechanical stress on the laminae, and maintain the integrity of the lamellar bond. Several trimming methods have been proposed, and many have been peer-reviewed, offering different mechanical hypotheses about how best to achieve these objectives.

This blog post will compare and contrast some of the most common mechanical hypotheses for hoof trimming protocols and provide guidance for a trimming strategy that can minimise the disruption of the lamellar bond and stabilise P3’s orientation within the hoof capsule. For more information on some of the protocols discussed take a look at our essential guide to laminitis

https://hoofflix.com/videos/owners-guide-to-laminitis-series/

1. Traditional Trimming Protocol

Mechanical Hypothesis: The traditional approach focuses on balancing the hoof by leveling the hoof capsule to match the natural alignment of P3. The trimming aims to maintain a consistent weight-bearing surface by ensuring that the hoof is trimmed evenly along its length and width. The theory is that if the weight is distributed evenly across the hoof wall, the laminae will bear less shear stress, allowing the hoof and P3 to be less affected by the rotational forces.

Research and Peer Review:

• Pros: Studies have shown that this approach helps in cases of chronic laminitis to maintain overall hoof balance, which reduces excessive strain on weakened laminae.
• Cons: However, this method doesn’t address the core issue of laminar detachment and P3 rotation in the acute stages of laminitis. In cases of severe rotation, this approach may inadvertently worsen the mechanical strain on P3, especially if it doesn’t account for the altered position of the coffin bone due to laminitis.

Effect on Lamellar Bond and P3 Stabilisation:

• Leveling alone may not sufficiently reduce the forces acting on the laminae during the acute phase of laminitis, leading to the continuation or worsening of P3 rotation.

2. The “Roller” or “Founder” Trim

Mechanical Hypothesis: This method involves elevating the heel and reducing the toe of the hoof capsule. The trim follows the contour of the hoof so that the breakover point (where the hoof leaves the ground) is moved backward. The idea is to reduce strain on the laminae by shifting the center of pressure away from the front of the hoof and reducing the impact on the sensitive tissues in the toe region.

Research and Peer Review:

• Pros: Some studies show that this trim can help reduce strain on the laminae and minimize rotation by decreasing the load on the toe. By shifting the weight distribution, it is thought to help prevent excessive tension from pulling the coffin bone further out of alignment.
• Cons: In severe cases of laminitis, a too-aggressive reduction of the toe could result in further damage to the laminar connection or destabilize the hoof wall’s attachment to P3.

Effect on Lamellar Bond and P3 Stabilisation:

• This trim has been shown to reduce tension on the laminae and provide relief to the coffin bone by shifting weight towards the heels. However, its effectiveness depends on the severity of the laminitis and how carefully it is executed.

3. The “Natural Balance” Trim (Mustang Trim)

Mechanical Hypothesis: The “Natural Balance” trim aims to preserve the natural alignment of the hoof and restore a biomechanical balance that closely mimics the horse’s natural movement. The focus is on trimming the hoof to maintain a proper breakover angle, with attention paid to the hoof’s internal architecture and the orientation of P3. This trim often includes the use of toe wedges or heel elevation, in conjunction with shoeing protocols, to help distribute weight more evenly and keep the coffin bone from rotating excessively.

Research and Peer Review:

• Pros: This protocol emphasizes prevention of further damage to the laminae by aligning the hoof to work optimally with the natural forces of the horse’s movement. Some studies have found that trimming for natural balance can help prevent excessive P3 rotation and improve stability in horses with laminitis, especially when combined with proper hoof support (e.g., central rather than peripheral shoeing modalities such as clogs).
• Cons: The protocol requires knowledge of hoof biomechanics and an understanding of the horse’s individual needs. There are concerns that this method may not be applicable to all horses, particularly those with severe laminitic damage.

Effect on Lamellar Bond and P3 Stabilisation:

• The primary benefit is that it reduces additional stress on the laminae and aligns the hoof capsule in a way that can support the structural integrity of P3. It can minimise further rotation of P3 and might be particularly effective in preventing exacerbation of the laminitis.

4. The “Palmar foot Elevation” 

Mechanical Hypothesis: In this protocol, the heels are elevated (sometimes with a soft pad), which is intended to relieve pressure on the laminae by redistributing the weight onto the back half of the hoof. The rationale is that elevating the heels helps reduce the rotation of P3 by relieving tension from the deep digital flexor, allowing it to realign with the hoof capsule and reducing the downward pressure on the laminae.

Research and Peer Review:

• Pros: This method can be highly effective in acute laminitis cases by helping to reduce rotation and relieve pain. Studies have demonstrated that elevating the heels can minimize further damage to the laminae and provide more time for the tissues to heal.
• Cons: This protocol can be controversial in terms of long-term adaptation since it can result in muscle and tendon changes in the lower limb. Additionally, improper use of pads or excessive heel elevation may cause tendon contracture and mechanical imbalances in the hoof over time.

Effect on Lamellar Bond and P3 Stabilisation:

• Heel elevation can be an effective short-term solution to relieve pressure on the laminae and prevent further rotation of P3. It also helps stabilize P3 within the capsule, though it should be carefully managed to avoid long-term issues.

Recommended Trimming Protocol Based on Peer-Reviewed Data

After comparing these protocols, the most effective trimming strategy to minimize P3 rotation and stabilize the lamellar bond will likely involve a combination of approachesbased on the stage of laminitis, severity of rotation, and individual horse biomechanics. Below is a proposed set of objectives for a trimming protocol:

1. Gradual Elevation of the Heels: Elevating the heels should be done cautiously and monitored closely and should always utilise the maximum palmar support base possible? This will help reduce pressure on the laminae,  engage palmar foot weight sharing and help miniseries excessive rotation of P3, especially in the acute phase of laminitis.
2. Balancing the Hoof with a Natural Breakover Point: The trim should aim to create a natural breakover while minimizing toe pressure. This helps to avoid exacerbating tension on the laminae, especially during movement.
3. Minimise Excessive Reduction of the Toe: Avoid drastic toe reduction (dorsal hoof wall thickness), as it may destabilise the laminae, increase dorsal hoof wall migration and or lead to further rotation. Preserve the integrity of the toe area while trimming for balance.
4. Support with Hoof suitable central load bearing modalities : Use appropriate supportive materials like hoof pads, boots or combinations such as clogs or heart bar shoes to provide additional load sharing platforms that will provide comfort and relieve the laminae during recovery.
5. Frequent, Conservative Trimming: In cases of laminitis, trimming should be done frequently but conservatively, focusing on maintaining balance and ensuring that no further strain is placed on the laminae during the healing process.
6. Monitor the Laminae Health: Close monitoring is necessary to detect early signs of laminal failure and adjust the trimming approach if needed. Any sign of increasing rotation or sinking of P3 should be addressed quickly with additional support and trimming adjustments.

Conclusion

The trimming protocol best suited to stabilize P3 and minimize disruption of the lamellar bond in cases of laminitis is one that combines elevation of the heels, balancing the hoof, and gradual, conservative trimming. It’s essential that the trimming strategy takes into account the individual condition of the horse and is adjusted as necessary, based on ongoing evaluation of the laminitis severity and P3 alignment.