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Barefoot methodology as a viable farriery option Stephen E. O'Grady and Hilary M. Clayton Reprinted with permission from the American Association of Equine Practitioners.
Summary The equine foot evolved to provide an effective interface between the distal limb and the ground for weight-bearing, shock absorption and providing traction. The use of horseshoes became necessary when horses performed a lot of work on abrasive surfaces. These days, however, most equine athletes train and compete on soft, manufactured surfaces that are conducive to having the horses barefooted, especially if they have good quality hooves and can be taken out of work for a short period of time while the hoof goes through the adaptive process. Being barefoot for a period of time is often useful in treating horses with chronic foot lameness, hoof capsule distortions with compromised heel structures, sheared heels or frogs that are either recessed or prolapsed relative to the ground surface of the foot. The benefits of being barefooted include superior shock absorption, better energy damping and improved weight-bearing ability. Without shoes, the foot undergoes greater expansion and vertical movement at the heels and foot shape is maintained by friction and wear between the entire solar surface of the foot and the ground. Shaping the barefoot hoof involves removing excessive hoof wall using hoof nippers at an angle of 45° dorsal to the sole-wall junction (white line) to create a bevel in the bearing surface of the hoof wall. The heels are rasped horizontally to the same horizontal plane as the frog which makes the palmar foot ‘load sharing’. Starting at the heel quarter, the rasp is used around the circumference of the foot at a 45° angle and then a rounding motion from proximal to distal is used to produce a thick rounded perimeter to the distal hoof wall. It is important to leave all the horn/mass on the solar surface of the foot for protection. Adaptation to being barefoot requires a period of time to allow the structures of the foot to strengthen along with reshaping of the foot at 3–4-week intervals. A version of this manuscript was presented at the American Association of Equine Practitioners Scientific Program in 2023.
INTRODUCTION The equine foot has evolved as the interface between the limb and the ground. Its functions include accepting the weight of the horse, providing shock absorption, dissipating the energy of impact, and providing traction (Clayton et al., 2011; Davies, 2007; O'Grady, 2016). A structurally healthy foot in its natural or barefoot state outperforms the shod foot in these functions. Furthermore, the structures of the foot have an inherent ability to change shape, strengthen and improve over time through the process of adaptation (Clayton et al., 2011; Davies, 2007). Horseshoes became a necessity in the nineteenth and twentieth centuries when horses worked/competed long hours on paved roads or abrasive surfaces. With the decline in working horses and the rise in popularity of equestrian sports performed on deformable synthetic surfaces, horseshoeing should no longer be regarded as a necessity. Indeed, at the 2021 Olympic Games in Tokyo, the Swedish team won the gold medal in showjumping with two of their three horses jumping barefoot over 18 rounds in 4 days. The following year, a barefoot Swedish horse won the FEI World Championship in showjumping. The fact that sport horses can and do perform at the highest levels without shoes challenges what has become the traditional practice of regarding a shod foot as the normal state. This should not be taken to infer that the authors believe traditional farriery using horseshoes should be abandoned, but rather to suggest that barefoot methodology presents another viable option in equine foot care.
WEIGHING THE OPTIONS Horseshoes provide protection when wear on the solar surface of the foot exceeds growth at the coronet, they maintain or enhance functionality by providing traction and offer the possibility of using therapeutic shoes to improve compromised structures of the foot and to treat disease and lameness. However, there are some negative consequences of a horse being shod. A horseshoe has very different mechanical properties than the hoof wall and should not be regarded as an extension of the horse's foot. The shoe replaces the single interface between the hoof capsule and the ground with two interfaces (Figure 1) (Eliashar, 2012; Parks, 2011). Within the musculoskeletal system, transitions between tissues with different mechanical properties are accomplished by a series of gradual changes in tissue properties that help to smooth force transmission. The abrupt transitions from hoof wall to shoe and from shoe to the ground, together with the material properties of the shoe alter concussion and dampening by the foot and lower limb, increasing impact acceleration on the hoof (Benoit et al., 1993; Eliashar, 2012; Roepstorff et al., 1999). Furthermore, applying a standard horseshoe to the horse's foot increases the force exerted on the navicular bone by the deep digital flexor tendon by up to 14% (Eliashar, 2012; Willemen et al., 2004). There are reasons to maintain a horse barefoot and there are reasons for using shoes. It is not the purpose of this paper to compare the pros and cons of barefoot versus shod. There is no doubt that traditional farriery using horseshoes can be performed in a proper physiological manner with minimal damage to the horse's foot (O'Grady & Poupard, 2003; O'Grady, 2009, 2020) but a successful outcome in transitioning a horse to barefoot methodology requires a different approach. The primary intent of this paper is to describe a consistently successful method to transition a horse from being shod to remaining barefoot using a simple and easy method of ‘shaping’ the foot in accordance with the basic farriery principles of trimming (O'Grady, 2009, 2020). One of the authors (SOG) has been successful in using this method to improve the deformable soft tissue structures in the palmar/plantar section of the foot in shod horses that have a distorted hoof capsule by leaving the horse barefoot for a period of time.
INDICATIONS FOR BAREFOOT In equine practice, a permanent or temporary transition to barefoot should be considered for horses that
BENEFITS OF BAREFOOT Maintaining horses in a barefoot condition should not be regarded as a fad that is rooted in minimalist ideas of equine management nor should it be regarded as a cure-all. There are, however, many aspects of going barefoot that pose a feasible and practical option to traditional farriery. The potential benefits to the horse and owner include the following:
The success of the authors and others in producing a limited but growing population of barefoot horses implies that this is a feasible farriery option. However, success in transitioning horses to being barefoot is dependent on understanding the process, applying the appropriate farriery principles and allowing time for the necessary changes to occur through adaptation.
THE BAREFOOT TRIM The preparation of a foot that will remain barefoot, either temporarily or permanently, differs from the preparation of a foot prior to being shod. When the horse will be shod, the foot is trimmed. When the horse will be barefoot, the foot is shaped. The biggest differences in preparing the barefoot hoof vs. preparing a hoof for shoes are
Briefly, the solar surface of the foot is cleaned briskly using a wire brush; a hoof knife is not required to shape the foot. Excessive hoof wall when present, usually at the toe, is removed using hoof nippers. Rather than cutting horn on the same horizontal plane as the sole, the nippers are angled at approximately 45° to the sole with the cut starting at the outer edge of the sole-wall junction (white line). Cutting the hoof wall at a 45°angle versus cutting the horn on a horizontal plane allows the hoof wall mass to be preserved for protection and a thick bevel can be created in the wall around the perimeter of the hoof (Figures 2 and 3). The goal is to preserve the bearing surface of the hoof wall and then be able to form a thick rounded peripheral edge. After removing excessive horn or toe length, the heels of the hoof capsule are rasped horizontally across the frog until the heels are on the same horizontal plane as the frog. This ensures that the palmar section of the foot is ‘load sharing’. Starting at the heel quarter, the rasp is then used at a 45° angle to the sole around the circumference of the foot to the sole-wall junction (Figure 4). The angle of the rasp creates a sharp edge at the bevel on the hoof wall which is removed by laying the rasp against the outer hoof wall surface and rasping in a rounding motion from proximal to distal on the hoof wall. This produces a thick rounded perimeter continuous with the outer hoof wall (Figure 5). Excessive hoof wall flares are removed using the rasp in the same manner to blend the flared area into the rounded perimeter of the hoof wall. This shaping protocol differs from the usual direction of rasping a foot during a routine trim and, initially, farriers often find the technique awkward or cumbersome. Regardless of whether the horse will be barefoot temporarily or is being transitioned to remaining barefoot, it is important to leave all the horn/mass on the solar surface of the foot.
THE TRANSITION FROM SHOD TO BAREFOOT The authors have advocated maintaining horses, including upperlevel competition horses, barefoot when this is feasible for many of the reasons outlined previously. Many factors/variables should be considered before deciding whether a horse is a candidate for the barefoot lifestyle. These include the type and amount of work performed, the surfaces on which the horse works, genetics, current hoof conformation, the integrity and mass of the hoof wall and, especially, the condition of the soft tissue structures in the palmar/ plantar foot. The severity of any of these factors individually or in combination may make the horse unsuitable to remain barefoot. The prerequisites for transitioning a horse to barefoot are:
When the horse wears shoes, the hoof is elevated off the ground and loading is concentrated around the periphery of the hoof wall. The sole-wall junction, sole, bars, digital cushion, and frog are deprived of interaction with the ground which leads to a loss of structural integrity, strength, and mass. These structures will adapt to changes in their environment, but an adequate transition period is necessary for the tissues to strengthen and improve their density in response to the removal of the shoes. If the hoof walls are thin and the sole at the toe deforms markedly when hoof testers are applied across the dorsal sole (indicating decreased sole depth), the use of a modified hoof cast can assist by adding mass, stability, and protection to the hoof capsule during the transition period without interfering with the physiological function of the foot or the adaption process (O'Grady & Poupard, 2021). Removing the horse's shoes without a transition period will seldom be successful. After removing the shoes, all the foot structures are involved in weight acceptance and these structures adapt to withstand changes in the biomechanical forces/load now placed on the foot (O'Grady, 2016). The shoes are removed toward the end of the shoeing cycle (4–5 weeks) when there is maximum hoof wall growth on the bottom of the foot. The length of the transition time depends on the quality of the hoof capsule structures when the shoes are removed. The authors recommend that the horse be walked daily in hand or under saddle for the first week. If the horse remains comfortable walking, then the routine progresses to turn out in a small paddock or round pen for a few hours daily and or slow-ridden exercise through the country on firm footing for the next few weeks. At 3–4 weeks, if sound, the horse is started back to arena work on firm (such as turf) or deformable footing. The feet are shaped at 3–4-week intervals as outlined in the trim protocol above, ensuring the hoof wall at the heels and the frog remain on the same horizontal plane to ensure that the palmar/plantar section of the foot ‘shares the weight’ and the structures in this area continue to improve. The length of the transition period depends on the condition of the feet when the shoes are removed and on how the horse responds to being barefoot during the transition period. Some horses go back to training in as little as 3 weeks and back to competition in as little as 5 weeks. This process is likely to be shorter when the horse works on a synthetic deformable surface rather than some type of firmer footing. Characteristics of horses that transition successfully from shoes to barefoot:
USING A MODIFIED HOOF CAST The application of 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 (O'Grady & Clayton, 2023; O'Grady & Poupard, 2021). When removing the shoes, the condition of the hoof wall is one of the critical factors that determines if and how long it takes to transition to being barefoot. The hoof wall may be thin, have poor consistency, multiple deep hoof wall separations, and vertical cracks around the bearing border. Furthermore, there may not be sufficient hoof wall at the bearing border of the foot to allow it to extend a few millimetres distal to the sole. In these cases, the use of a modified hoof cast affords stability, provides additional mass, and protects the hoof capsule without interfering with any physiological functions or the adaptation process. The cast is applied to the outer hoof wall so that at least 4–5 millimetres of the cast extends beyond the perimeter of the hoof capsule. The cast material is removed across the heels, so it does not interfere with the normal physiology of the foot during weight bearing (Figure 7). The veterinarian, farrier or trainer can readily apply the modified hoof cast on a barefoot horse if indicated. A modified hoof cast may be a useful aid, but it must be emphasised that boots should be avoided during the transition phase as ‘boots are not barefoot.’ Boots place a thick interface between the foot and the ground, which changes the forces on the foot and interferes with the adaptation process.
PROVIDING TRACTION Most hunters, jumpers and dressage horses perform on synthetic deformable surfaces, and traction has not presented a problem. However, some high-profile jumper classes are held on turf arenas, and horses may require additional traction, especially if the surface is wet or muddy. This may present a safety issue for the barefoot horse and its rider. This can be managed by fitting a pair/set of shoes to the horse without trimming or changing the solar surface of the foot. The shoes are attached using four small nails and, when the horse has finished competing, the shoes are removed and the horse continues barefoot. This scenario requires a little more work on the part of the farrier but has been shown to fulfil the need or necessity for additional traction.
VETERINARY APPLICATIONS OF BAREFOOT METHODOLOGY TO IMPROVE THE PALMAR FOOT Equine veterinarians are often confronted with horses that have lameness associated with distortion of the palmar/plantar part of the foot, especially involving the deformable soft tissue structures (Castelijns, 2012; O'Grady, 2013; O'Grady and Castelijns, 2011). Two common problems are a sheared heel and low/underrun heels combined with a negative angle of the solar border of the distal phalanx. Although many farriery techniques have been described to address these types of abnormal hoof conformations, none has shown consistent documented success. When given the opportunity and time, the author (SOG) has always rehabilitated distorted hoof capsules and poor hoof conformation without shoes and consistently had good results over the years. Based on the records of 70 horses, 50 of which were actively competing, only two horses that met the prerequisites could not be transitioned from wearing shoes to barefoot. Both horses had chronic lameness issues.
Sheared heels Sheared heels are generally caused by abnormal limb or foot conformation that leads to an asymmetrical landing pattern with overloading of one side of the foot. The over-loaded heel/heel quarter is pushed upward causing proximal displacement of the coronet. This, in turn, predisposes the foot to various injuries including bruising (corns), extensive separations and quarter cracks. Removing the shoes for as little as 7 days will redistribute the weight on the bottom of the foot and allow the displaced heel to open, relax and descend into a more acceptable position. When a quarter crack is present, the coronet will be displaced proximally at the origin of the defect. Removing the shoes allows the coronet to settle distally into normal alignment before any type of repair is considered (Figure 8). On average, it takes 7–10 days to improve sheared heels.
Low or underrun heels Low or underrun heels, which are often seen in combination with shoes that are too small, are characterised by forward migration of the heels to a position dorsal to the base of the frog. Forward migration of the heels reduces the load-bearing surface area, so the forces applied during locomotion are distributed over a smaller surface area. The resulting increase in heel pressure reduces heel growth and the frog, which is now situated palmar/plantar to the heels of the hoof capsule, prolapses distally between the branches of the shoe. The horn at the heels is worn down further when the heels of the hoof capsule expand against the surface of the shoe during weight bearing. One author (SOG) has consistently improved the palmar foot structures by taking the horse out of work and giving them time without their shoes. After removing the shoes from a horse with underrun heels, the frog will generally be prolapsed below the level of the hoof wall. The first objective is to get the frog and the hoof wall on the same horizontal plane to allow all structures to participate in load sharing. This is accomplished by having the horse stand/walk on a firm surface during the first week after removing the shoes so that the weight of the horse levels the bearing surface. Any excessive toe length is reduced using the hoof nippers as described above and then creating a bevel in the toe. It is important to preserve all mass on the solar surface of the foot. The heels can be rasped in a horizontal direction, that is, across the frog within 10–14 days, to remove the folded underrun horn at the heels after which the bars/angle of the sole will begin to become apparent (Figure 9). During the period without shoes, the horse is managed as described for the transition to the barefoot state. Improvements in the integrity of the hoof wall and sole thickness can be verified with hoof testers across the dorsal sole and/or lateral radiographs. The amount of time necessary without shoes varies and is determined by the owner/trainer, farrier and clinician. When shoes are replaced, strict attention is paid to the trim and to the size, type and placement of the shoe using as guidelines, the hoof-pastern axis, the position of the centre of rotation and trimming the heels to the base of the frog or trimming to the same horizontal plane as the frog (O'Grady, 2009). The average time needed to improve low or underrun heels is 4–6 weeks.
CONCLUSIONS Success in transitioning horses from shod to barefoot is based on the veterinarian, farrier, trainer and owner understanding and being willing to adhere to the entire transitional process. The essential steps are to
The authors have had consistent success in transitioning horses to barefoot primarily due to the cooperation of all parties involved. Trainers/riders state that stride kinematics change when the horse is barefoot and unpublished data show that barefoot jumpers have greater clearance over fences, possibly because the weight of a shoe attached to the distal end of the limb affects leverage and kinematics during jumping.
AUTHOR CONTRIBUTIONS Stephen E. O'Grady: Conceptualization; investigation; writing – original draft; methodology; validation; visualization. Hilary M. Clayton: Investigation; writing – original draft; validation; visualization.
FUNDING INFORMATION None.
CONFLICT OF INTEREST STATEMENT No conflicts of interest have been declared.
ETHICS STATEMENT All work done in the author's practice is acceptable standard of care guidelines.
ORCID Stephen E. O’Grady https://orcid.org/0000-0001-6243-7724 Hilary M. Clayton https://orcid.org/0000-0002-8759-0925
REFERENCES
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