Hopefully you read Dr. Stephen O’Grady’s excellent article, “Barefoot or Shod?  It Depends...” in the March issue. This month I’d like to add a little to what he said and expand a bit on managing the barefoot horse.

Contrary to popular opinion, many horses do not need to be shod. Horse shoes are one of the many time-honored traditions in the horse industry that few people question. The fact is, shoes that are nailed or glued to the horse’s hoof can limit the normal function of the foot, as I’ll explain in a minute. On the other hand, a lot of horses cannot comfortably live and work without some sort of mechanical aid, and these horses should be provided with appropriate shoes or slip-on hoof boots (something I’ll also discuss a little later).

Functions of the Hoof

The main function of the horse’s foot is to serve as a base of support for the limb, and thus to support the weight of the body. The hoof capsule—the insensitive outer structure which comprises the horn of the hoof wall, sole, and frog—plays a vital role in this function, as it protects and supports the bones, joints, and sensitive soft tissues within.

That much is obvious. What is not so apparent is the fact that the hoof also functions as a sensory structure which plays an important role in locomotion. The underside of the hoof is the horse’s only means of direct contact with the ground during locomotion, so the hoof’s function in “reading” the ground surface (the slope, hardness/softness, irregularities, slipperiness, etc.) is very important for safe and efficient movement, especially at high speed.

In order for the horse to move with speed and agility across varying terrain, the sensory structures within the hoof and elsewhere in the limb (particularly joints, tendons, and ligaments) must rapidly and accurately provide information about the ground surface to the central nervous system (the CNS, which comprises the brain and spinal cord). The CNS then sends an appropriate response back to the muscles that are responsible for limb placement.

In this way, each foot is placed and each limb is loaded optimally for the next stride. This process allows the horse to move in a smooth, coordinated, safe, and efficient manner, making fine adjustments with each stride in response to changes in the ground surface.

All this transmission of information—sensation and response—must happen within milliseconds at the faster gaits. At the average working canter, the horse takes around 90 strides per minute, and at the gallop over 120 strides per minute. In other words, each stride is completed in about 0.7 seconds at the canter and less than 0.5 seconds at the gallop. So, at the gallop, sensory information must make it all the way up the limb, from the ground to the spinal cord, and a motor response must make it back down to the muscles of the limb, all within half a second!

The various soft tissues within the hoof are abundantly supplied with sensory receptors—specialized nerve endings which convey information to the CNS via their associated sensory nerves. Some of these sensory receptors (called nociceptors) convey the sense of pain when tissues within the hoof capsule are damaged or in danger of being damaged. It is these receptors that cause the horse to lift his foot quickly when he stands on a sharp stone.

But there are several other types of sensory receptors within the hoof that do a different job: they inform the CNS about ground contact, the position of the foot, and the way it is loaded. These other receptors (called mechanoreceptors) are widely distributed across the underside of the foot, and are most plentiful in the back half of the foot (the heels and frog). More than the nociceptors, these receptors are involved in smooth and coordinated locomotion, particularly at high speed or over uneven ground.

With this array of sensitive and specific receptors, each sending slightly different information to the CNS, the horse is able to quickly and accurately perceive a wide variety of sensations and respond appropriately as the particular conditions or circumstances require, whether it be negotiating irregular terrain at high speed, digging in on a slippery corner, or lifting the foot off a hidden rock before the sole is damaged.

Shod vs. Barefoot

Even the most basic horse shoe lifts the underside of the hoof off the ground. That is one of the purposes of the shoe: to protect the underside of the hoof from potentially damaging or simply painful events, such as stepping on a stone. However, in so doing, the shoe substantially reduces the contact of the hoof with its environment. It also alters the way the hoof capsule changes in shape when the horse bears weight on the foot, because the shoe nails restrict normal deformation of the hoof capsule from the last nail forward. This, too, affects the information received by the CNS, as sensory receptors are also abundant within the soft tissues of the hoof wall.

So, the shoe substantially alters the amount and type of information received by the CNS, and thus the horse’s ability to accurately perceive and respond to her environment. Most horses quickly adapt to wearing shoes, and presumably they learn how to negotiate their terrain by relying on sensory information from other parts of the lower limb, just as we are able to walk, run, jump, dance, etc. in shoes. But how much better it would be for the locomotory system to be allowed the full range of information available to it.

Provided that the horse is comfortable going barefoot, he’ll tend to move better and be more sure-footed on the trails. Horses who perform activities that require precision of foot placement, such as dressage, sports involving tight turns (barrel racing, gaming, etc.), and those performed at speed over variable terrain (eventing, endurance, competitive driving, etc.), also may benefit from going barefoot.

But let me reiterate that some horses cannot comfortably go barefoot. Their foot conformation, pre-existing foot pathology, or the type of work they do requires the protection of some sort of shoe or boot in order for them to live and work comfortably.

Hoof Boots

In recent years, hoof boots have undergone some major transformations from the clunky ol’ EasyBoot. Hoof boots these days are so much more than “medicine” boots, designed to protect an injured foot or hold medication on a hoof. There are now several types of hoof boots that are specifically designed to be worn by horses during exercise. Here are six:

* Boa Horse Boot (www.EasyCareInc.com)

* Hoofwings (www.HorseSneaker.com)

* Marquis Supergrip Boot (www.StrideEquus.com)

* Old Mac’s Generation 2 Hoof Boot (www.EasyCareInc.com)

* Renegade Hoof Boot (www.RenegadeHoofBoots.com)

* Simple Boot (www.SimpleBoot.com)

My two favorites for the average pleasure horse are Hoofwings and Renegades. The Marquis Supergrip is designed for high-level performance, but it is more expensive than the other hoof boots and probably more than the average pleasure horse needs.

At between $100 and $200 a pair, hoof boots are a great investment for those with barefoot horses, and even for those with shod horses who do a lot of back-country trail riding. Boots are invaluable during the tender-footed period many horses go through when transitioning from shod to barefoot. They also provide great hoof protection and comfort when working on hard or rocky terrain. Most horses adjust very quickly to wearing boots, and they move just as well with boots as without; in fact, some horses move with more ease and confidence on hard or rocky ground with their boots on than without.

In closing, going barefoot is not for every horse or horse owner, but it’s something to at least consider. Although going barefoot does save on shoeing costs, it is still necessary to work closely with a good farrier or barefoot trimmer, as most domestic horses need regular trimming to keep their feet in good shape, comfortable, and functioning properly. Barefoot trimming is something you can learn to do yourself, but for the first year or so, you should continue to work closely with an experienced trimmer.