Virginia Therapeutic Farriery
 
 
Barefoot Methodology — Another Farriery Option
Find greater success when transitioning a shod horse to barefoot with this protocol and technique
 
Stephen E. O’Grady, DVM, MRCVS, and Agustin Rosales (contributing author)
 
 
      The equine foot with healthy structures is superior in its barefoot state with regard to accepting weight, dissipating the energy of impact and absorbing concussion.1 Furthermore, the structures of the foot have an inherent ability to change, strengthen and improve over time by the process of adaptation.1 Shoes are applied to prevent wear, add traction and provide a means to apply therapeutic farriery when necessary. As a farrier and veterinarian, I have always been a proponent of allowing a horse to remain barefoot or compete barefoot when possible.2
    When given the opportunity and time, I try to rehabilitate distorted or compromised feet, especially the palmar/plantar section of the foot, in the barefoot state.2 Still, to be clear, I also believe a horse can be trimmed and shod in a proper physiological manner with minimal damage to the hoof capsule.3,4 The advances in synthetic and deformable footing at competitions and on farms have allowed many horses to compete barefoot. At the 2021 Olympic Games in Tokyo, Japan, the Swedish show jumping team won the gold medal, competing with their horses barefoot, creating a renewed interest in this farriery option. Many upper-level equine athletes can compete barefoot, but for success, the veterinarian and farrier must understand the process and implement a different approach to the farriery. Understanding barefoot methodology and attention to detail provides another viable farriery option.
 
 
 
Applying a Horseshoe
 
      Applying a horseshoe to a horse’s foot will change the density and the functionality of the hoof structures, so a brief look at the effects of using a shoe may be insightful. The horseshoe is not an extension of the horse’s foot, as we often hear. Placing a horseshoe with different properties than the hoof capsule between the hoof and the ground replaces a single interface with two interfaces.5,6 Changing the interface will invariably have consequences on foot function. This interface alters the concussion-dampening effect on the lower limb, resulting in increased impact intensity on the hoof.7 Applying a shoe will shift weight-bearing to the hoof wall or periphery of the foot, decreasing the load on the adjacent structures.
      Furthermore, the shoe elevates the hoof off the ground surface, which can increase pressure on the navicular bone by the deep digital flexor tendon by as much as 14% and result in less heel expansion when compared with the unshod foot.8,9 The hoof growth and wear process allows the barefoot horse to maintain the shape of its feet by friction and thus wear between the ground and the entire solar surface of the foot. When a horse is shod, friction will occur between the expanding heel of the hoof capsule against the shoe, which induces more significant wear at the heel than wear at the toe, which is responsible for the difference in the toe and heel angle over a 4- to 6-week shoeing cycle.10
 
 
The Trim
 
      I learned the farriery trade through an apprenticeship with Hall of Fame farrier Joe Pierce. I was taught that the trim applied to a barefoot should be different from the trim used for a foot being shod. In my practice, the difference in the farriery can be described as “when the horse is being shod, the foot is trimmed; when the horse is being left barefoot, the foot is shaped.” The difference is the solar surface is left intact, and the hoof wall is left 3 to 5 mm longer for as much protection as possible when barefoot. The solar surface of the foot is initially brushed briskly with a wire brush.
       The hoof knife is generally not used other than to remove extraneous, exfoliating horny tissue from the frog. If there is excessive hoof wall to be removed, hoof nippers will be used but not in the usual fashion of cutting hoof wall on the same horizontal plane as the sole. Instead, the nippers are held vertically at an angle of approximately 45 degrees, and the cut begins on the outer side of the sole-wall junction (white line) (Figure 1). The goal is to bevel the bearing surface of the wall, which decreases length but preserves mass.
A rasp is used to trim the heels in a horizontal direction across the frog to the point where the heels of the hoof capsule are on the same plane as the frog, making the palmar/plantar section of the foot “load sharing.” If the frog is prolapsed below the foot’s solar surface, this will correct within a few days of the horse being barefoot. Starting at the heel quarter, the rasp is used vertically at a 45-degree angle around the foot’s circumference, staying on the outer side of the sole-wall junction (Figure 2). The angle of the rasp will create a sharp edge at the lower end of the bevel, which is removed by laying the rasp against the outer hoof wall surface and rasping toward the bevel with a rounding motion to remove the sharp edge, resulting in a thick rounded edge that is continuous with the outer hoof wall (Figures 3a and 3b). Excessive hoof wall flares are removed from the outer hoof wall using the same process with more pressure placed on the rasp to blend this area into the rounded perimeter of the hoof wall.
      Horses that have worn shoes for considerable time are likely to have some degree of hoof wall separation between the toe and heel quarters. If the toe and heel sections of the foot dorsal and palmar to the separations are intact and strong, the separations can be removed by placing the rasp at a more acute angle and removing the separated outer hoof wall. The wall is removed to where the sole-wall junction becomes solid, and the wall blends into the rounded perimeter of the hoof. The toe and heel structures can accept the weight-bearing function, and the quarters will grow out with a solid sole-wall junction (Figures 4a and 4b).
The trim can be modified according to the amount of horn present or the conformation of the foot. Trimming the bearing border of the wall in this manner will also prevent chipping and cracking around the perimeter of the hoof wall. This trimming protocol may seem awkward or cumbersome to farriers as it differs from their usual direction of rasping a foot during a routine trim.
 
 
 
Nippers are used at a vertical angle starting the cut dorsal to the white line. This will create a thin mound of hoof wall and a thin white line (red arrow) on the bearing border of the foot. Rasp is used on a 45-degree angle dorsal to the white line. Note the mound of hoof wall (3 to 5 mm) being formed and again the thin white line (red arrow) around the perimeter.
 
 
A shows the sharp edge created when using the rasp vertically. Figure 3b shows the thick, rounded perimeter created by using the rasp against the outer hoof wall to remove the sharp edge.
 
 
Foot shaped to remain barefoot in Figure 4a. Note the separations between the toe and heel quarters. Figure 4b shows separations between the toe and heel separations being removed using the rasp at a steep angle trimmed to a solid sole-wall junction.
 
 
The Process
 
      I have been an advocate of maintaining upper-level competition horses (or any horse) barefoot when this type of farriery is feasible or possible. Following the recent publicity, I have seen many clients request that their farrier remove the horses’ shoes; the feet are trimmed in the usual manner, and the horses become uncomfortable only to have their shoes replaced. Word spreads quickly through the horse industry that this is not a good farriery option.
      There are many factors/variables to consider when deciding whether a horse is a candidate to leave barefoot. These may include the type and amount of work expected of the horse, surfaces on which the horse works, genetics, current hoof conformation, the integrity and mass of the palmar foot, and the current condition/health of the structures of the hoof capsule. The amount of involvement of any of these factors or a combination of these factors may make the horse not amendable to compete barefoot. When the horse wears shoes, it should be remembered that the hoof is raised off the ground, and the major load is placed on the periphery of the hoof wall. Being above ground, the sole-wall junction, the sole, bars, digital cushion and frog will lose some structural integrity and density from lack of stimulation or interaction with the ground due to the interface created by the shoe. Additionally, the sole thickness will invariably decrease with shoes, thus limiting its protective nature.
      The structures of the hoof capsule will change density through the process of adaptation; therefore, an adequate transition period for adaptation of the foot is essential when attempting to change from shoes to barefoot. If the hoof walls are thin and the sole at the toe markedly deforms when hoof testers are applied, the use of a modified hoof cast can be used to assist with the transition as it will add mass, stability and protection to the hoof capsule during the transition period without interfering with the physiological function of the foot.
 
 
A Unique Partnership
 
      I have worked for several years with Agustin Rosales, a manager/trainer at one of the large jumper barns where I consult. He asked me if I would teach him to trim feet using the turnouts on his farm, as they often had trouble finding a farrier to do these horses. Rosales quickly became handy using farrier tools and proficient trimming the field horses, which are all barefoot. After I remove the shoes on the selected horses to go barefoot and perform the initial trim, Rosales can do the subsequent trims and maintain the shape of the feet. His trimming the barefoot horses does not interfere with their regular farrier who does the other horses that remain shod, in fact, they encouraged him, as farriers often do.
      Horses are selected for having good hoof conformation/structures or the potential for the structures of the hoof capsule to improve and strengthen. Horses with poor hoof structures in the palmar/plantar foot or those with significant hoof capsule distortions are not selected. The shoes are generally removed just before the horse is due to be shod at 4 to 5 weeks, as there will be some hoof wall growth on the bottom of the foot. The feet are trimmed as described above, emphasizing that no horn be removed from the solar surface of the foot. The hoof wall at the heels and frog are trimmed to the same plane using the rasp, and the remainder of the trimming is performed using the rasp in a vertical direction starting on the outer side of the sole-wall junction.
 
 
The Transition Period
 
      Removing the horse’s shoes without a transition period will seldom be successful. The hoof structures need time to adapt, strengthen, change shape and improve the integrity of the hoof capsule. When the horse is barefoot, all the foot structures will be used to accept weight rather than relying on the hoof wall and the protection afforded by the shoes (Figure 5). With the shoes removed, the foot will adapt relative to the change in the biomechanical forces now placed on the foot. The length of time is dependent on the quality of the hoof capsule when the shoes are removed.
      I generally recommend that the horse be walked once or twice a day (15 to 20 minutes) on a firm surface for a few days. If the horse remains comfortable hand walking, the horse may be turned out in a small area (paddock or round pen) for a few hours daily and or be ridden through the country on firm footing for the next few weeks. At this time, if sound, the horse is started back to work in an arena setting with deformable footing. The feet are trimmed (shaped) at 3- to 4-week intervals as outlined in the trim protocol above, ensuring the hoof wall at the heels and the frog remain on the same plane as the palmar/plantar section of the foot needs to “share the weight.” The transition period will depend on the condition of the feet when the shoes are removed and how the horse responds during the transition period to being barefoot.
      It should be emphasized that boots should be avoided during the transition phase, as “boots are not barefoot.” Boots place an interface between the foot and the ground, which changes the forces on the foot and prevents adaptation. I have had some horses go back to competition in as little as 3 weeks. This process will further depend on whether the horse goes back to work on a synthetic deformable or some type of firmer footing.
 
 
The foot needs time to adapt and strengthen from having the weight-bearing concentrated on the hoof wall and then being transferred to all the structures.
 
 
A Modified Hoof Cast
 
      Applying a modified hoof cast at the onset or during the transition period may augment the process and, in some cases, decrease the time necessary to transition to barefoot. When removing the shoes, the hoof wall condition is one of the critical factors that determine if and how long it takes to transition to barefoot. The hoof wall thickness may be thin, have poor consistency, multiple deep hoof wall separations, cracks around the hoof capsules bearing border and the heel base (hoof wall, bars and the angle of the sole) may be collapsed or underrun. Furthermore, there may not be sufficient hoof wall at the bearing border of the foot to allow it to extend a few millimeters distal to the sole.
      The hoof cast affords stability, provides additional mass and protects the hoof capsule without interfering with any physiological functions or improving the structures. The cast is applied to the outer hoof wall so that at least 3 to 4 mm of the cast will extend beyond the perimeter of the hoof capsule. The foot is placed on the ground after the cast is wrapped with plastic wrap and begins to cure. The horse’s weight causes the excess cast to fold under the foot and form a protective layer of cast material on the solar surface around the bearing border of the foot (Figures 6a and 6b). The farrier or the trainer can readily apply the modified hoof cast on a barefoot horse (Figure 7).
 
 
Lateral and solar view of a modified hoof cast. On the solar view, note the layer of cast around the perimeter of the hoof wall and the palmar section of the cast removed so the cast does not interfere with the physiology of the foot.
 
 
Trainer Agustin Rosales applying a hoof cast.
 
 
Traction
 
      Most hunters, jumpers and dressage horses perform on synthetic or deformable surfaces, and traction has not yet presented a problem with this option. However, some jumper or Grand Prix courses are held on the grass, and horses may require additional traction, especially if the surface is wet. The grass is not the routine environment of the barefoot horse, so we fit a pair/set of shoes to the horse without trimming or changing the foot.
      The shoes are attached using four nails. When the horse has finished the class(es), the shoes are removed and the horse continues barefoot. This scenario requires more work for the farrier, but has shown to fulfill the need or necessity for traction. Success in transitioning horses from shoes to barefoot is based on the farrier’s, veterinarian’s, trainer’s and owner’s understanding and willingness to adhere to the entire process. Selecting horses with suitable hoof structures or hoof structures that can improve and strengthen is essential — combined with changing the farriery performed on the horse from trimming the foot to the concept of shaping the foot. And finally, the transition period is vital as it’s essential to allow the feet time to adapt, strengthen, change shape and improve the integrity of the hoof capsule. We have had success with this transition primarily because of all parties’ cooperation. Trainers/riders state that the strides change on the horse when barefoot, and the clearance over the jumps is markedly higher (Figure 8). Perhaps this will be proven in the future. However, the success that we and others have had with a limited but growing number of horses seems to imply this is a feasible farriery option when using the appropriate principles.
 
 
Rosales competing and winning with a jumper that had his shoes removed for a month.
 
 
References
 
  1. Davies HM. Biomechanics of the equine foot. In: Floyd AE, Mansmann RA, eds. Equine Podiatry. St Louis (MO): Elsevier, 2007; 42-56.
  2. O’Grady SE. Various aspects of barefoot Methodology relevant to equine veterinary practice. Equine Vet Edu 2016 28(6):321-326.
  3. O’Grady SE, Poupard DA. Physiologic horseshoeing: an overview. Equine Vet Edu 2003;13:330-334.
  4. O’Grady, S.E. Principles of Trimming and Shoeing. In: Baxter GM, ed. Adams and Stashak’s Lameness in Horses 7th ed. Ames, IA: Wiley-Blackwell, 2020;1095-1111.
  5. Parks AH, The Practice of Shoeing. In: Ross MW and Dyson SJ, eds. Lameness in the Horse 2nd ed. St. Louis (Mo) Elsevier, 2011;301-303.
  6. Eliashar, E 2012. “The Biomechanics of the Equine Foot as it Pertains to Farriery.” Vet Clin No Amer Equine Pract 2012:28(2):284-91.
  7. Roepstorff L, Johnston C, Drevemo S. “The Effects of Shoeing on Kinetics and Kinematics during the Stance Phase.” Equine Vet J Suppl 1999;30:279-85.
  8. Roepstorff L, Johnston C, Drevemo S. “In Vivo and in Vitro Heel Expansion in Relation to Shoeing and Frog Pressure.” Equine Vet J Suppl 2001:54-57.
  9. Willemen MA, Savelberg HH, Barneveld A. “The Effect of Orthopaedic Shoeing on the Force Exerted by the Deep Digital Flexor Tendon on the Navicular Bone in Horses.” Equine Vet J 1999;31:25-30.
  10. Moleman M, van Heel MC, van Weeren PR, Back W. “Hoof Growth Between Two Shoeing Sessions Leads to a Substantial Increase of the Moment about the Distal, but not the Proximal, Interphalangeal Joint.” Equine Vet J 2006;38:170-174.
  11. O’Grady SE, Poupard DA. “How to Incorporate a Modified Hoof Cast into Equine Veterinary Practice.” Proceedings. Am Assoc of Equine Pract 2021; 67:218-125.