Last summer, four well-preserved Roman-era horseshoes were excavated along the legendary Hadrian’s Wall in northern England. The unearthed iron pieces are ornate, yet seemingly practical, with etched treads on the bottom for traction. Dated between A.D. 140 and 180, these “hipposandals” would have cupped the hoof, fastening with leather straps. They were probably the height of hoofwear technology at the time.
By the seventh century, the general practice was to affix horseshoes to the hoof with nails. Overall, how shoes are applied hasn’t changed a lot since then. But what has changed is that the hardest-working equines (at least in the developed world) are primarily athletes now, not labourers. Still, like their utilitarian forebears, most sport horses wear metal shoes for protection, shock absorption, traction and support. Technology, combined with our ever-growing understanding of equine anatomy and biomechanics, is surely, albeit slowly, changing how performance horses are shod.
Metal Horse Shoes for the Win
Nail-on metal shoes remain the standard sport horse footwear. “It works. It’s reliable and affordable,” says Alberta farrier Connor Sloman, who, alongside his father, Lance, operates Equiterra Farrier Services. The company specializes in hunters and jumpers and has a long-standing association with Spruce Meadows in Calgary.
While steel shoes are sturdy and durable, these qualities can also be their shortcoming, he says. “It wears down the horse’s heels in particular. As the hoof expands and contracts on top of the fixed surface [of the shoe], the steel can rub on the heels while the toe still grows. So you end up with a long toe and low heel.”
Aluminum shoes are softer and lighter than steel, but that means they don’t wear as well and need replacement more often. They’re generally more expensive, too, with prices averaging around $17 to $23 per shoe compared to steel’s $8 or $9. However, they are prevalent in the show ring. For example, says Sloman, many elite jumpers these days favour wide-web aluminum shoes for a larger base of support and increased sole protection. (The web is the measure from inner to outer edge of a shoe branch.)
“They have some better technologies in the aluminum shoes now; better alloys where you can still heat the shoes up, shape them and hot-fit them. Before, you would heat them up and they would lose their temper – they would get too soft.”
One of metal’s main drawbacks is that the shoes need to be nailed into the hoof often, potentially weakening its structure. And, says Sloman, “If the shoes are improperly installed or a horse has thinner walls, then the shoe can get torn off.”
However, new innovations are helping mitigate nail issues. Sloman has recently switched to mainly using copper-coated nails, which became available about four years ago. The copper plating is intended to bolster the nail’s strength so it doesn’t shear as easily, and new research has shown it also inhibits microbial growth inside the hoof. Sloman says they’re slightly more expensive at about 13 cents compared to an average 10 cents per nail. The large horseshoe and nail manufacturer Mustad has also recently come out with a line of nails covered in its proprietary “Endura” coating which is reputed to be stronger, reduces hoof-wall damage, and is anti-corrosive.
Glue-on Horse Shoes are Gaining Ground
To avoid the nail issue altogether, horse people have tried for decades to find an alternative through glue-on shoes. The main sticking point (sorry) has mainly been the quality of adhesives. The first formulas, adapted from the airline industry, failed when exposed to moisture. Now, acrylic and urethane adhesives set faster and bear up better under environmental and equine pressures.
Glue-ons have notably been used with great success for therapeutic and rehabilitation purposes and are relatively ubiquitous at Thoroughbred racetracks. But now they’re also being spotted in the show ring, especially on horses with thin or compromised hoof walls or feet that can’t be conventionally shod for whatever reason.
There’s an extensive range of glue-on shoes on the market. “I just came back from the International Hoof Care Summit in Cincinnati and they had ten to fifteen different versions,” says Sloman. Some product lines even offer shoes specifically geared toward certain disciplines.
With the direct-glue approach, metal or plastic shoes are bonded right onto the hoof wall. In particular, Sloman is partial to Polyflex Horseshoes by Florida-based No Anvil LLC, which are polyurethane with wire inside to aid in shaping the shoe to the hoof. Other glue-ons are tab or cuff style like the GluShu, an aluminum shoe with a moulded flexible rubber outer piece that’s attached to the outer hoof wall. Some, like the polyurethane EponaShoe line, can be either nailed or glued.
While the proliferation of glue-ons indicates a desire for such products, they aren’t exactly finding their way to performance horses’ feet … yet. “There were about a thousand horses at Spruce Meadows during the summer series and there were maybe four horses with glue-on shoes,” says Sloman, noting that a major deterrent is price. “The shoes can be up to four times as much as a regular steel shoe – sometimes more.”
Depending on the product, application can be labour-intensive, taking as long as two hours per foot. The feet must be extensively cleaned and dried, as adhesives can seal in bacteria. Another negative, says Sloman: “The hoof wall underneath the adhesive changes consistency and becomes more pithy underneath the adhesion area. It no longer has the same consistency and strength as the rest of the hoof wall.”
Sloman adds that adhesives’ strong bond can be problematic. “While some view the nail and the traditional shoe as detrimental, it can be beneficial. When a shoe is pulled or lost with a well-fitted and nailed shoe, it will usually come off cleanly and with little damage to the hoof wall,” explains Sloman. “With a glue-on, because the adhesion level is extremely high, when a shoe is accidentally pulled it can lead to removal of the hoof wall and surrounding areas as well.”
Is the Future of Horse Shoes 3-D?
Nevertheless, technology continues to advance and impact what goes on our horse’s feet, whether it’s improved adhesives, innovative shoe designs or new materials. One of the most promising areas is 3-D printing. In 2013, media reports abounded when Australia’s national science agency created custom titanium shoes for a racehorse using a hand-held 3-D scanner and modelling software. While the horse didn’t ever actually wear the shoes, the agency did subsequently successfully fit a set to a laminitic mare.
Scan-and-print isn’t at the point where it’s commercially viable, although it is being used regularly behind the scenes to develop new state-of-the-art equine footwear. It will likely be a decade or two before it’s commonplace for our farriers to reach for their 3-D equipment rather than their forge, but in the meantime they will have a plethora of shoeing options to outfit our competition horses’ hooves.