An expert to whom we turn for this discussion is Olin Balch, DVM, MS, PhD, who is in private practice in Washington state. Balch has written various treatises on matters concerning the equine foot and also has been featured on American Association of Equine Practitioners educational programs.
The key issue, Balch maintains, revolves around normal wear of the hoof capsule as compared to its growth rate. In many horses, he says, the wear does not exceed growth and, when this is the case, shoeing might not be necessary. However, if the wear rate exceeds the growth rate, then shoeing might be needed to maintain the foot in a healthy, balanced state.
Doug Butler, PhD, a Colorado author and widely known consultant on shoeing and overall hoof care, says that in general, the average hoof growth rate for all horses is about three-eighths of an inch (one centimeter) per month. However, he also notes that some variables can affect this. For example, the rate of growth is faster in summer months than in winter. Horses receiving proper nutrition will have faster-growing hooves than horses eating inappropriate diets. Exercised horses have more rapid hoof growth than do horses that are idle. Hooves grow faster in young horses than in mature animals. In general, the back hooves grow faster than the front.
In addition, Balch says, wear rates depend on the surface over which the horse is worked, exercised, or allowed to roam. If the surface is hard and abrasive, the rate of wear will be greater than over one that is soft and yielding--the difference between dry, rocky country as opposed to lush pasture, for example.
Horses that compete in endurance contests over rough ground, or trail riding horses who normally are ridden in rocky, mountainous terrain, would be likely candidates for hoof wear that exceeds growth, and they might require regular foot protection to maintain soundness. On the other hand, horses that only walk, jog, and lope on soft, sandy surfaces might very well have hoof growth rates that exceed wear rates.
The shoeing decision must be made on an individual basis, both experts agree. Some horses have more sensitive soles than others, for instance, and will be prone to such problems as stone bruising if not shod. Some of these horses have soles so sensitive that they will flinch when walking over a gravel surface, while others with tough, thick soles can trot through a rocky area without discomfort.
Balch is of the opinion that if a horse's hooves are so soft or sensitive that they can't withstand normal traffic barefoot over the local terrain, then perhaps there should be a change in location for them. In other words, a horse with very sensitive soles would fare better in a southern climate where the ground often is covered with grass that is soft and yielding than he would on a western mountain slope where the pasture contains rocks and hard-surface outcroppings.
However, he adds, even if the horse is moved to a more suitable locale, questions have been raised concerning whether he should be used as a brood animal to produce offspring that might inherit his thin, weak hooves.
There sometimes is a predilection for hoof problems based on breed. Speaking in generalities, this writer has found that Arabians tend to have much more durable hooves than Thoroughbreds, for instance. Many Arabians spend hours and miles on the trail and are not shod. There is a reason. Through the years, the Arabian was developed as a horse that had the stamina to travel for miles with little water or food and, at the same time, had hard hooves that allowed it to remain sound.
By contrast, the Thoroughbred has been bred for speed, with some aspects of its anatomy that are affected by genetic makeup, such as hooves, playing only a minor role when breeding decisions are made. As a result, a number of Thoroughbreds have thin soles and frequently a crumbly or less-than-healthy hoof wall. If horses of this type are used on surfaces that are anything other than soft and yielding, they will suffer bruising and excessive hoof wall wear and shoeing will be necessary to keep them sound.
However, shoeing is not a cure-all for these horses. Some of them have hoof walls that are so weak that they won't hold a nail. The good news is that positive strides have been made in the development of glue-on and buckle-on shoes.
What Age to Shoe?
Back to Balch and the questions of if and when to shoe. In general, he says, in brood stock and young horses, hoof wear rarely exceeds growth and shoeing is unnecessary. For horses in this category, he believes, routine trimming to keep the hoof balanced is all that is needed.
At the same time, Balch is well aware that a number of horse owners with young animals that are being prepared for the show or sale ring will demand that they be shod for cosmetic and corrective reasons.
He takes a dim view of this approach. Far better, he asserts, that the breeder look to genetics for good leg and hoof conformation when breeding, rather than turning to a farrier to solve problems after the fact.
"No amount of farrier or veterinarian work can substitute for good breeding," he says.
In fact, Balch opines, more harm than good may be inadvertently done with "corrective" shoeing or trimming of young horses. Yes, he says, you might be able to get that turned out or turned in hoof pointed in the correct direction, but at the same time you might be twisting the joints above (particularly the fetlock) to abnormal angles. An incorrect angle can cause undue stress on the entire limb structure, he says. Unnatural torque could be applied with each step taken.
Often, Balch said, the farrier is "on a slippery slope" when dealing with owners who want corrective work done on their young horses for either show or sale purposes. On the one hand, he says, the farriers know that in many cases they are not truly correcting anything, but at the same time, they are aware that if the owner is determined, he or she is going to get someone else to do the work.
Whenever possible, Balch reiterates, it is healthier for young horses and brood stock to remain barefoot rather than being shod.
That being said, Balch also points out that there are cases where trimming that could be called corrective might be required to maintain balance in a young, developing hoof. A prime example, he says, might involve a young, growing horse with long, straight legs, but an uncharacteristically short neck. A young horse with that type of conformation, he says, will tend to stand in a spraddle-legged fashion when grazing, with the front feet wide apart so that it can reach grass with its teeth and, thus, it will apply more weight or pressure on the inside of the front feet than the outside.
The result, he says, might be front hooves that exhibit excessive wear on the inside and lack appropriate wear on the outer edges. In order to keep the foot balanced, he says, "corrective" trimming would involve removing more wall from the outer edge of the hoof capsule or wall so that the youngster's foot is balanced.
There might also be a situation, Balch notes, where the young horse has rapid toe growth and the resultant long toes do not permit correct breakover. When that is the case, he says, it might be necessary to "square off" the toes so the foot is balanced and will break over properly.
Regular, timely trimming can generally keep the young, growing foot in a balanced state, Balch believes. Rarely is shoeing of the youngster required unless it is suffering from congenital and/or acquired flexural limb deformities. When that is the case, an entirely different protocol might be involved that is beyond the scope of this discussion.
Shoeing For Environment
In cases where the discipline or the surface over which the horse travels brings about wear that exceeds growth, Balch says, the question is not whether to shoe, but when to shoe. If a horse is going to require shoes while performing in a particular discipline, the timing of when to shoe can be critical. In other words, if one waits until a horse is lame, such as from a stone bruise, valuable time can be lost in the conditioning and training processes. It would be much better in such an instance, he says, to apply shoes when the conditioning program begins.
However, Balch says, shoeing a mature or developing performance horse to correct a limb deformity can be far more detrimental than helpful. As was mentioned with the young horse, the "corrective" shoeing might cause the hoof to point in the correct direction, but at the expense of the overall well-being of the limb. In most cases, Balch says, such trimming or shoeing will compromise rather than assist the horse's overall performance capability.
Hoof Anatomy and Change
Balch pauses in the discussion at this point to discuss basic hoof conformation so that one can better understand what is being attempted when trimming and shoeing.
First, there is the part of the hoof that is readily visible--the hoof capsule--which is made up of a horny (insensitive) exterior or wall as well as the sole and frog on the underside of the foot. The exterior portion of the hoof is designed to protect the sensitive inner foot and its associated vascular and nervous tissue from trauma when the horse walks, runs, or jumps. Bruising of the corium or sensitive tissues of the foot, Balch says, is one of the prime causes of lameness, thus underlying the point that proper care of the hoof capsule is highly important.
The prime goal in trimming and shoeing, Balch says, is to help the horse develop a balanced foot that will absorb concussion without damage to the sensitive inner structure or unnatural stress and strain on the limb above it.
Again, the approach must be on an individual basis. The horse with a long toe and tender sole must be trimmed and shod differently than the one with a short toe and a thicker sole. The horse with the short toe, he explains, must be allowed to have a sole that is thick enough to protect the inner sensitive structure. The horse with the long toe must have that part of the hoof pared down to the point where it no longer exerts undue leverage and hinders breakover.
As alluded to earlier, there has been progress in developing shoeing approaches that involve methods and materials other than nailing on metal shoes. Glue-on shoes today, Balch says, are much more horse- and farrier-friendly than they were in the past, and buckle-on shoes, such as Easy Boots, have even been used successfully in endurance races and other disciplines. These newer approaches, Balch says, protect the hoof and may allow more expansion of the hoof capsule than traditional steel shoes.
No matter what type of foot protection is used, Balch says, its purpose is to serve as an extension of the hoof capsule that will protect the foot against undue wear and shield the sensitive inner foot structures.
In the final analysis, Balch concludes, the decision of whether to shoe your horse or not, and when, depends on the individual horse involved and the owner's goals for that horse. If it is a young, growing horse, a broodmare, or a stallion, shoeing might not be required. If it is a horse that will be involved in a discipline that requires serious conditioning or a particular gait is involved, then shoeing will likely be the approach of choice.
Whatever the decision, the key is to try to do what is best for the horse, whether that is leaving a good-footed horse au natural or putting protection in the form of boots, glue-ons, or shoes on a horse that needs it.
About the Author
Les Sellnow is a free-lance writer based near Riverton, Wyo. He specializes in articles on equine research, and operates a ranch where he raises horses and livestock. He has authored several fiction and non-fiction books, including Understanding Equine Lameness and Understanding The Young Horse, published by Eclipse Press and available at www.exclusivelyequine.com or by calling 800/582-5604.