To Shoe or Not to Shoe? Part 4: Benefits of Being Barefoot

Photo: Alexandra Beckstett, The Horse Managing Editor
A Healthier Foot

Allowing a horse to go barefoot for even just part of the year can be beneficial and promote soundness. In the article “Barefoot Benefits” Gabrielle Pullen (2001) summarizes Robert Bowker’s examination of 125 barefoot horses (never shod) and 10 show horses (previously always shod) that had their shoes removed for the non-competition seasons. His findings demonstrated that when allowed to go barefoot, a horse’s feet will eventually regain characteristics associated with a “healthier” foot.

In the 10 show horses studied, conformation of the feet showed signs of change within three weeks of shoe removal, exhibiting a widening of the hooves, increased shallowness of the soles, callus formation on the toe of the soles, and a shortened breakover distance. After six to nine weeks foot width increased, the frogs became larger and had more contact with the ground, increasing the weight-bearing area of the sole and reducing stress on the hoof walls. Bowker found that “these horse’s adapted barefoot hoof characteristics [were] the same as those found in sound hooves with no internal problems” (Pullen, 2001).

Proprioception

In addition to the flexible properties of the hoof previously described, the hoof also has a significant role in the horse’s sense of proprioception. Proprioception is “the perception by an animal of stimuli relating to its own position, posture, equilibrium, or internal condition” (Encyclopedia Britannica).

Robert Bowker’s research postulates that the hoof has receptors that are similar to those that stimulate skin sensations in other species, which might explain why horse’s feet respond differently to different surfaces. If the hoof is, in fact, a sensitive and responsive organ, then altering its surface by applying shoes will likely interfere with the horse’s innate sense of proprioception (Pullen, 2001).

According to the veterinarian Tomas Teskey (2005) and the farrier Ward Edwards (2012), horseshoes significantly impair a horse’s sense of proprioception. Similar to a gloved hand, the shod hoof has dulled sensitivity and is only able to get a general feel of the surface it is in contact with. When there is a lack of sensory feedback, the horse may inadvertently pay less attention to where its feet are landing and be less surefooted. Its ability to compensate and adjust weight on uneven or slippery footing will also be inhibited, making the horse more prone to injury.

To Shoe or Not to Shoe? That is the Question

In conclusion, I’d like to reiterate a few points from Part 1.

When deciding whether or not to shoe a horse, a number of factors must be carefully considered, including the genetics and breed of the horse, individual hoof conformation, the climate the horse lives in, and the type of footing on which it works or performs. Ultimately, hoof structure is the determining factor in deciding what is best for a particular horse (O’Grady, 2007).

If a horse is in good health, has good conformation, and its hooves are properly cared for, there’s no reason for shoes or other footwear under normal circumstances. However, the case can definitely be made to shoe a horse for therapeutic or work/performance purposes. Each horse must be considered individually. It is unreasonable to think that all horses must be shod, or conversely, that all horses should be barefoot.

References

Edwards, W. (2012). “Barefoot Benefits.” Farrier Service Plus: Whole Horse Farriery. Retrieved from http://www.farrierserviceplus.com/tag/proprioception/

Encyclopedia Britannica. “Proprioception.” Retrieved from https://www.britannica.com/science/proprioception

O’Grady, S. (2007). “Barefoot vs. Shod? It depends…” Virginia Therapeutic Farriery. Originally published in American Farriers Journal Jan/Feb 2007. Retrieved from http://www.equipodiatry.com/article_barefoot_v_shod.htm

Pullen, G. (2001). “Barefoot Benefits.” The Horse Jul 1, 2001. Retrieved from http://www.thehorse.com/articles/10855/barefoot-benefits

Teskey, T. (2005). “The Unfettered Foot” A Paradigm Change for Equine Podiatry.” Journal of Equine Veterinary Science 25(2) (2005) 77-83

To Shoe or Not to Shoe? Part 3: The Shod Horse

Photo credit: David Goldman, Associated Press
Performance and Therapy

Despite the hoof being a very resilient and adaptive structure, horses engaging in strenuous performance sports often require shoes for extra support, protection to preserve the hoof capsule and structures contained within it, and traction for the safety of both horse and rider (Bryant, 1999). Horseshoes can be shaped to compensate for hoof irregularities while offering support to the feet and legs and protecting the toe of the hoof from wear. The majority of shoes remain open at the heel to allow for the natural flexion and expansion of the hoof when it comes into contact with the ground, leaving the frog and sole uncovered because of their important role in shock absorption (Bryant, 1999; O’Grady, 2008).

A variety of shoeing materials and styles are used based on the discipline in which the horse performs, the breed and natural conformation of the horse, and the ground surface it performs on. For example, Thoroughbreds are shod with very thin aluminum shoes called racing plates, whereas hunters wear much thicker, but still lightweight, aluminum shoes. In contrast, high-stepping horses like the Tennessee Walker are often (controversially) outfitted with weighted shoes and pads on hooves with an extra long toe and disproportionately short heel to exaggerate their natural gait, as the heavier shoe forces the horse to heighten its step (Bryant, 1999; Montgomery, 2014).

For therapeutic purposes, shoes can be used to provide additional heel support to horses that have low heels, treat cases of laminitis and navicular disease, and repair quarter cracks by shifting the weight distribution on the hoof wall (Bryant, 1999).

The Farriers Role

The role of the farrier is to maintain and promote a healthy hoof wall, an appropriate sole depth, and soft tissue structures of a sufficient mass to properly support the bones, tendons, and ligaments within the hoof (O’Grady, 2007). There are three main forces that are altered by farriery – independent of the application of shoes – and play a role in foot pathology and therapy. These are 1) ground reaction force – the upward force of the ground on the hoof; 2) the force of the horse’s weight transmitted downward through the limb; and 3) the upward pull of the deep digital flexor tendon (Corp-Minamiji, 2015).

Once the hoof has been evenly trimmed and balanced by the farrier, a variety of shoes can be applied for performance and therapeutic purposes. The following list highlights those that are used in therapy (Bryant, 1999; Corp-Minamiji, 2015; O’Grady, 2008).

  1. Straight bar shoes provide extra heel support for damaged or under-run heels and stabilize the downward pressure of the foot, creating an evener distribution of weight.
  2. In feet with well-developed frogs, the heart-bar shoe may be used. This shoe covers the frog and transfers some of the weight from the wall of the hoof to the soft tissues, which can be helpful in treating cases of laminitis and quarter cracks.
  3. The oval egg-bar covers the back portion of the hoof to offer extra support for horses with low heels.
  4. The practice of wedging with pads and/or rails applied to the shoe shifts the forces on the foot and affects the position of the coffin joint, which can be beneficial for horses that have advanced cases of laminitis with coffin bone rotation.
  5. Wooden shoes cut from plywood are strictly used for therapeutic purposes, easing breakover and decreasing force on the lamella.  
  6. Glue-on shoes can be used on horses to eliminate the need for nails in cases where the horse has poor-quality feet but requires shoes for a short time.

Under the right circumstances, horseshoes can be highly beneficial to the health, comfort, and conformation of a horse, however, not all shoes are created equal. For example, O’Grady (2008) indicates that egg-bar and other bar-type shoes increase concussive forces from hard surfaces, and Ovnicek (2003) believes that “conventional shoes (non-orthopedic) can stand in the way of the hoof’s natural function”.

A Few Problems with Horseshoes

“Horseshoes are a necessary evil!” say some (Pullen, 2001). “Forcing the flexible hoof to function when restricted by a rigid, steel shoe is a powerful prescription for promoting the hoof’s deterioration”, says Tomas Teskey (2005), one of the more vocal critics.

The hoof is a flexible structure designed to expand and contract in response to the ground surface (footing), moisture and concussive force. The natural response of the hoof is to flex outward 2 to 4 millimeters when it is bearing weight. The degree of flexion is in response to the hardness of the footing. When shod this movement is impeded and the hoof is not able to function as it normally would. “If you draw a chalk line around the foot of a shod horse standing on hard ground, then do the same thing 15 minutes after the shoe has been pulled, you will find that the foot has expanded beyond the original line” (Pullen, 2001).

Furthermore, when a horse is shod, the majority of its weight is loaded onto the perimeter of the hoof wall. According to Robert Bowker, “only a small percentage of the load should be on the hoof wall, with the sole, frog, and bars bearing the majority” of the force, which will strengthen the foot and reduce the concussive force transmitted to the bone through connective tissues (DeFee Mendik, 2016).

Improperly fitted shoes can also cause a variety of problems, including hoof cracks, low heels, and sheared heels. Sheared heels are caused by uneven heel trimming in shod horses but are rare in barefoot horses because the taller heel is naturally worn down (Equine Research, 2004).

References

Bryant, J. (1999). “A Footwear Primer.” The Horse. Retrieved from www.thehorse.com/articles/10364/a-footwearprimer

Corp-Minamiji, C. (2015). “Therapeutic Shoeing Part 2: Hardware and Healing.” The Horse. Retrieved from www.thehorse.com/articles/28437/therapeutic-shoeing-part-2-hardware-and-healing

DeFee Mendik, N. (2016) “Back to Barefoot.” The Horse. Retrieved from http://www.thehorse.com/articles/31022/back-to-barefoot

Equine Research. (2004). Horse Conformation: Structure, Soundness, and Performance. Guilford, Connecticut: The Lyons Press.

Montgomery, M. (2014). “Exposed! Tennessee Walking Horse Celebration: Celebrating Cruelty?” One Green Planet. Retrieved from www.onegreenplanet.org/animalsandnature/exposed-tennessee-walking-horse-celebration-celebrating-cruelty

O’Grady, S. (2007). “Barefoot vs. Shod? It depends…” Virginia Therapeutic Farriery. Originally published in American Farriers Journal Jan/Feb 2007. Retrieved from http://www.equipodiatry.com/article_barefoot_v_shod.htm

O’Grady, S. (2008). “Basic Farriery for the Performance Horse.” Veterinary Clinics: Equine Practice vol. 24 (2008) 203-218

Ovnicek, G. et al. (2003). “Natural balance trimming and shoeing: its theory and application.” Vet Clin Equine 19 (2003) 353-377

Pullen, G. (2001). “Barefoot Benefits.” The Horse. Retrieved from http://www.thehorse.com/articles/10855/barefoot-benefits

Teskey, T. (2005). “The Unfettered Foot” A Paradigm Change for Equine Podiatry.” Journal of Equine Veterinary Science 25(2) (2005) 77-83

To Shoe or Not to Shoe? Part 2: The Horn of Plenty

An intricate and complicated host of tissues, blood vessels, tendons, ligaments and bones comprise the [horse’s] foot, and the whole package is sealed within a hard, horny shell – the hoof wall. – Lester Sellnow, 2001

Image: Anatomy of a Healthy Hoof, Animal Health Trust
Structure of the Hoof

The hoof has evolved to serve a number of important functions for the horse, including supporting an incredible amount of weight, absorbing shock, providing traction and conducting moisture. The hoof wall is essentially a self-replenishing keratinized horn. More specifically, it is a series of keratinized cells arranged in parallel tubules that run perpendicular from the coronary band at the top to the bottom surface of the wall. The outermost layer that forms the hoof wall begins at the coronet, the band separating the skin of the lower leg from the hoof, and is composed of the stratum externum (periople) and the stratum tectorium (Hood & Larson, 2013; Sellnow 2001).

The periople is similar to the cuticle of the human fingernail. It protects the junction between the horn and the skin, and extends less than ¾ of an inch down from the coronary band around the entire hoof, and to the bulbs of the heels at the back. The bulbs are the most flexible part of the hoof, allowing the foot to change shape in response to weight-bearing forces upon ground contact. The stratum tectorium is a thin shiny layer similar to the human fingernail. It gives the hoof a glossy appearance and helps retain moisture (Equine Research, 2004; Hood & Larson, 2013; Sellnow, 2001).

The stratum medium, the middle layer of the hoof wall, is the densest portion of the hoof, and as such, bears most of the weight of the horse. This layer consists of two zones. The outer zone is quite rigid and serves as a barrier between the foot and the external environment, while the inner zone is quite flexible and elastic, contributing to the hoof capsule’s ability to change shape in response to force. The innermost part of the hoof wall is the stratum internum (insensitive laminar layer). It consists of hundreds of alternating epidermal and dermal folds called laminae. Approximately 600 insensitive primary laminae project from the inside surface of the hoof wall, each one branching off into secondary and tertiary laminae. The laminae secure the coffin bone and attach it to the hoof wall  (Hood & Larson, 2013).

The solar surface of the hoof is directly exposed to the ground. Its main function is to support the internal weight of the foot and dissipate concussive forces in the leg. In most domestic horses the outer wall is the primary weight-bearing structure, while the sole takes on more of this role on softer footing. Other sections of the solar surface that come into contact with the ground are the heels, frog, and bars, with the heels being the first part of the foot to make contact when the horse is in motion. The size and hardness of the frog changes in response to water content and ground contact, and plays an important role in biomechanical function and shock absorption with its ability to widen and dissipate concussive force when the heel strikes the ground. The bars are thought to act as a spring, adding to the biomechanical forces that simultaneously cause the hoof to flatten and the heels to expand  (Equine Research, 2004; Hood & Larson, 2013).

The Feral Hoof

The hooves of feral and domestic horses are not the same. They differ vastly in shape, look and feel. Horse’s hooves have developed over thousands of years to adapt to a range of ground conditions, and the hooves of feral horses are shaped by their environment. Even though some feral horses tend to have a ‘conventional’ looking hoof shape that has been used as a model for domestic hoof care, the way in which the hoof capsule functions and interacts with the ground is in sharp contrast to the way the hooves of domestic horses are typically managed, and should not be readily adopted.

In contrast to the domestic horse, feral horses have thicker, stronger hoof walls that sometimes become rounded and have little to no ground contact. In many cases, particularly for horses living in dry conditions with hard footing, the sole has more contact with the ground than does the hoof wall. This ground contact of the sole changes the shape and function of the frog, which becomes much larger. In the words of Gene Ovnicek, the soles of feral horses are “calloused and the frog like a patch of leather” (Jurga, 2001). Robert Bowker has discovered similar findings, indicating that for the most part feral horses bear “their weight on their soles and frogs, which [are] enormous compared to the frogs of domestic horses” (Jurga, 2001).

At the opposite end of the spectrum, the hooves of horses living in sandy environments tend to develop spike-like hooks on their heels, which are present to a lesser degree on horses living in prairie, sod or gravel environments. In any of these softer conditions, horses are prone to hoof growth rates that exceed natural wear, resulting in a longer, flared hoof capsule (Jurga, 2001; Ovnicek, 2003).

Brian Hampson and Chris Pollitt (2011) elaborate that the balance between hoof capsule wear and growth rate in horses living in environments with hard footing results in a short hoof capsule that is worn to the level of the peripheral sole, leading to the sole bearing a significant portion of the horse’s weight. It is this hoof shape that has been promoted as being an ideal model for the domestic horse. However, Hampson and Pollitt believe this is actually detrimental to foot health, as indicated by the high incidence of laminitis and other foot pathologies in the horses they have studied.

The majority of the feral hooves studied by Hampson and Pollitt (this included 14 separate studies with horses ranging in number from 12 to 100 per group) showed extremely high incidences of pathology, ranging from less severe abnormalities like hoof wall cracks, flares, imbalances, narrow and uneven heels, to more serious abnormalities in the horses living in hard, rocky or desert environments, like concussive laminitis, rotated coffin bones, excessive hoof wall thickness, and ungual cartilage calcification (sidebone).

Basically, although the hooves of feral horses look robust and have been naturally modified to withstand locomotion in their respective environments, there are many negative pathologies, which, somehow, the horses are able to live with and continue to thrive under natural and sometimes harsh conditions (Hampson & Pollitt, 2011).

The “feral” or “natural” hoof, although touted by some based on the strength and durability of the hooves of feral horses living in hard, rocky environments, is not suitable for domestic horses because a) they do not wear their hooves enough naturally to maintain a healthy hoof length, and b) while the hooves of feral horses are “self-trimmed” because of distances travelled for food and water, they do have a high incidence of foot pathology.  In the case of domestic horses, whether the hoof is shod or bare, the skills and knowledge of a good farrier are essential to maintaining healthy, balanced feet.

References

Animal Health Trust. “Learn About Laminitis.” Retrieved from http://www.aht.org.uk/cms-display/cal_laminitis.html

Hampson, B.A. & C.C. Pollitt. (2011). Improving the Foot Health of the Domestic Horse: The relevance of the feral horse foot model. Australian Government, Rural Industries Research and Development Corporation: RIRDC Publication No. 11/140, RIRDC Project No. PRJ-002510. November 2011

Equine Research. (2004). Horse Conformation: Structure, Soundness, and Performance. Guilford, Connecticut: The Lyons Press.

Hood, D.M. & C.K. Larson. (2013). Building the Equine Hoof. Eden Prairie, Minnesota: Zinpro Corporation.

Jurga, F. (2001). “The Natural Hoof – A Sign of the Times.” The Horse Oct. 10, 2001. Retrieved from http://www.thehorse.com/articles/10671/the-natural-hoof-a-sign-of-the-times

Ovnicek, G. et al. (2003). “Natural balance trimming and shoeing: its theory and application.” Vet Clin Equine 19 (2003) 353-377

Sellnow, L. (2001). “The Equine Foot – Form and Function.” The Horse Oct 15, 2001. Retrieved from http://www.thehorse.com/articles/10753/the-equine-foot-form-and-function

 

 

To Shoe or Not to Shoe? Part 1

While those who strongly believe in shoeing seem to be of the opinion that it is the right and only way, many barefoot advocates believe that although barefoot is better, shoes are sometimes necessary.

Prior to enrolling in the Equine Functional Anatomy course offered by Equine Guelph, I had no idea that one’s decision to shoe their horse or keep it barefoot could be such a contentious issue. It was a fascinating topic to research! Never having given it much thought myself (I’ve never ridden a shod horse nor had I ever questioned why some horses are shod while others are not) I’ve come away with an informed opinion on the topic that boils down to the following.

When deciding whether or not to shoe a horse, a number of factors must be carefully considered, including the genetics and breed of the horse, individual hoof conformation, the climate the horse lives in, and the type of footing on which it works or performs. Ultimately, hoof structure is the determining factor in deciding what is best for a particular horse.

If a horse is in good health, has good conformation, and its hooves are properly cared for, there’s no reason for shoes or other footwear under normal circumstances. However, the case can definitely be made to shoe a horse for therapeutic or work/performance purposes. Each horse must be considered individually. It is unreasonable to think that all horses must be shod, or conversely, that all horses should be barefoot.

Even some of the more outspoken advocates for barefoot horses would still caution that not all horses are able to go barefoot. 

Part 2: The Horn of Plenty examines the form and function of the hoof, looking at the hooves of both feral and domestic horses.

Part 3: The Shod Horse takes a look at the therapeutic and performance-related uses of horseshoes as well as the harm caused to the exterior of the hoof by their overuse.

Part 4: Benefits of Being Barefoot advocates for a wider adoption of barefoot hooves and a more natural approach to hoof care when possible, not to be confused with the “feral” or “natural” model, which is also problematic, as discussed in Part 2.