Although some would argue that going barefoot is more natural for the horse in the long run, the fact remains that barefoot horses still face many of the same health concerns that shod horses do — and perhaps are at greater risk for developing complications from walking on man-made or rough terrains. Yet when a client insists that their horse is better off barefoot, what can a farrier do?

Years ago, there were no alternatives to traditional horseshoes. Now, farriers can recommend nontraditional solutions to owners who would rather their horses go barefoot. One of these solutions is the hoof boot. The use of hoof boots to protect the barefoot horse was recently made the focus of two studies conducted at Western Kentucky University in Bowling Green, Ky.

In 2017, Dr. Jennifer Gill, assistant professor of equine science in the university’s Agricultural Equestrian Unit, and undergraduate student Tabatha Stratton researched the potential benefits hoof boots can have for barefoot horses. To examine how hoof boots can benefit the horse, Gill and Stratton looked at two different areas in which hoof boots might support the foot: relieving pressure from concussive forces and offering protection to the external hoof wall. They presented their findings at this year’s International Hoof-Care Summit (IHCS).

“Although some horses do very well barefoot, some horses’ hoof structures cannot withstand riding or turnout on abrasive terrains, and this can lead to hoof damage and lameness. It can also throw the horse’s center of balance off,” Gill says.

Gill and Stratton both chose to use Cavallo Trek hoof boots in their studies. Stratton particularly liked the levels of comfort, durability and safety that the boots offered, which influenced her decision to use them. Since she would be studying the effect hoof boots have on reducing the number of chips and cracks in horses’ hooves, Stratton wanted a solution that would provide as much protection as possible without any permanent adhesives being applied to the hoof capsule.

“They’re very simple to apply,” Stratton says. “You just open up the straps at the toe and you have the middle section there, that’s called the tongue, and that opens up as well and it allows you to slide the hoof right into it.”

Tabatha Stratton records the condition of one of the horses participating in her study. “Sonny” was one of five horses used in Stratton’s study, and is also a member of Western Kentucky University’s resident herd.

Protective Measures

Stratton used the hoof boots in her study to determine whether they would offer any protection for barefoot horses during exercise in different environments. She randomly selected five horses from the university’s resident herd to participate in the study: four Quarter Horses and one Paint. All of the horses selected were determined to be sound and healthy at the beginning of the study, and were each trimmed by farrier Chuck York 3 days prior to the start of the study. Digital X-rays of the horses’ feet were also evaluated by veterinarian Dr. John O’Brien before the exercise began.

Stratton had several research questions she sought to answer during the course of her study, all of which would help to answer her ultimate question: do hoof boots offer substantial protection to barefoot horses? She decided to determine this by measuring the amount of cracking and chipping that occurred in each horse’s hooves during the study. She looked at whether this damage happened during exercise, if it seemed to increase or decrease based on the type of terrain the horses were exercised on, if damage happened when the horses were not being exercised and if the hoof boots generally met her performance expectations.

Stratton exercised the horses on three different types of terrain (crushed stone fines, arena sand and grass) to try to get a full picture of the Cavallo Trek hoof boot’s capabilities. She also made sure that each horse followed the same exercise schedule: longeing for 20 minutes in a 20-meter circle on the different surfaces, three times a week on Monday (on grass), Wednesday (on arena sand) and Friday (on crushed stone fines). During each exercise session, the horses were walked for 5 minutes and then trotted for 5 minutes in one direction. After 10 minutes, Stratton would have the horse change directions and repeat the process. She also made sure that the horses were allowed to rest between exercise periods. This exercise routine lasted for 6 weeks during the fall academic semester.

“We alternated between barefoot and booted each week,” Stratton said. “Precautions were made where the horses had a break after being exercised on the crushed stone fines, just in case they became sore. This way, they had some time to recuperate. Then we followed this up with exercising them on soft green grass for comfort.”

Measurements of the horses’ front hooves were taken in millimeters before and after each exercise session using a flexible measuring tape. This was done to monitor any damage that resulted from either exercise or turnout. Anything under 2 millimeters was considered to be normal wear and was not recorded. Once measurements of the horses’ hooves had been taken, Stratton analyzed the data set using a repeated measures analysis of variance design using SAS software and compiled the data she had collected into graphs using graphpad Prism software.

Tabatha Stratton uses a flexible measuring tape to examine the hooves of a horse participating in her study. Measurements of any damage were made in millimeters, with damage under 2 millimeters being disregarded.

Counteracting Concussive Forces

Gill had a similar goal for the study she was conducting: to find out whether Cavallo Trek hoof boots would change the pressure distribution on different riding surfaces, as well as to propose a new model for evaluating hoof pressure dynamics by using a film product to map the distribution of hoof pressure. One horse was used for the study — a 10-year-old Quarter Horse mare from the university’s resident herd. At the beginning of Gill’s study, the horse’s hooves were determined to be in normal condition using X-ray analysis. It was also trimmed by farrier Chuck York 5 days before Gill collected the data she needed.

Gill had the mare blindfolded and then walked over a 6-foot sheet of Fuji Prescale Pressure Film, a type of film that changes color depending on the amount of pressure applied to it. This was done over three different types of terrain: crushed stone, concrete and grass. For each type of terrain, the mare was walked over a different sheet of pressure-recording film barefoot and booted. After the mare had been walked over the film on each terrain, the hoof prints left behind were cut out of the film and sent to Sensor Products Corp. for analysis. Sensor Products used a type of imaging software called Topaq to create pseudo-color images that clearly displayed the range in pressure being applied between the hoof and the ground surface.

Gill notes that this method reveals very intricate details about each specific hoof and the impact a boot might have versus the general information detected by force plates.

She continues that, “the highest pressure regions are shown here in the red, and then the lowest pressure regions are shown in the dark purple (Figures 1-3). As you can see, the greatest pressure is exhibited kind of on the outer perimeter of the hoof, so the contacting surface is mostly the outer hoof wall and the outer tread here in the booted image. You can see how both images have a similar loading pattern where the toe and the lateral quarters are exhibiting the greatest force.”

An Alternative For Barefoot Horses

Despite studying the different applications hoof boots have, Stratton and Gill’s studies share an important conclusion: hoof boots do offer protection for horses that otherwise go barefoot, especially on terrains that could contribute to the development of wear or uneven pressure distribution in horses’ feet.

“Overall, the number of cracks and chips measured was less when booted than barefoot during the 6-week period on all three riding surfaces, and this was in favor of using the hoof boot while exercising the horse,” Stratton said of her study.

In Stratton’s case, Cavallo hoof boots provide some protection from cracking and chipping to the hoof wall of barefoot horses during exercise. However, the hoof boots may provide more benefit if used for protecting the barefoot horse during turnout. Stratton observed that most of the damage occurred in the absence of exercise.

“Because of the small size and area, validity of measurement for change in individual cracks and chips was not reliable pre-imposed exercise … the data suggests in favor of using some type of hoof protection in barefoot horses to reduce hoof damage during exercise and turnout,” Stratton says.

Gill found that the tread of the Cavallo Trek hoof boot spread out the pressure over a greater surface area of the foot when coming in contact with hard surfaces. This was demonstrated numerically by a lower average pressure on the film when the horse was wearing the hoof boots than when the horse was barefoot. However, on the grass terrain, the pressure was confined to only the boot tread, leading to an increase in average pressure compared to being barefoot.

“It’s quite possible that the boot tread may have actually concentrated the force onto a smaller surface area instead of the entire sole surface, thereby increasing the total pressure,” Gill says about the data she received from testing on grass terrain. “The soft surface may have actually spread that force over more of the solar surface and heels, and the frog may have actually contacted that surface, perhaps eve lower than the detectable range that this film is exhibiting.”

Gill also discussed how the pressure distribution changed from hard to soft surfaces. As a percentage of the scanned area, the highest detectable pressure of 1,400 PSI was detected in 25%, 2.5% and 0.1% of the analyzed film area when the horse was walked over concrete, crushed stone and grass, respectively (Figure 4).

Even though both Gill and Stratton concluded that more testing would need to be done to fully understand the ways hoof boots can reduce wear and damage to the hoof wall and reduce the concussive forces of the bare foot during exercise, their studies on the benefits hoof boots can have for barefoot horses have helped to lay the foundation for future research.

“Previous research acknowledges that hooves vary in strength, hardness, angle, alignment and structure ... there are also other factors that can affect hoof biomechanics and ultimately affect the soundness of the horse. Some of these factors can be genetic, so the horse’s conformation, the climate a horse is kept in, growth or wear between trimming intervals, the type of trimming method that a farrier might employ and the type of ground surface that the hoof comes in contact with can all have an affect,” says Gill.

Their studies also demonstrate that giving barefoot horses protection and support on rough terrains will prolong the healthy state of their hooves. Even more importantly perhaps, their findings give farriers evidence that they can offer this type of hoof protection to horse owners who might disagree with the idea of using any sort of shoe on their horses’ feet.

July/August 2018 Issue Contents