Research: Clayton and Bowker's “Effects of Barefoot Trimming on Hoof Morphology” Focuses on Incremental Heel Recovery

"Lights, cameras, heel angles..." Dr. Hilary Clayton uses the most advanced data collection and analysis systems in the world to track how horses move, grow, stand or even sway. Her electronics matched with Dr Robert Bowker's anatomy studies have placed Michigan State University at the epicenter of global hoof research. Since both Clayton and Bowker espouse the advantages of barefoot hoofcare, it's natural that a study with both names as authors would be published. (McPhail Center photo)

Hilary Clayton, BVMS, PhD, MRCVS has an office in the airy, bright new Mary Anne McPhail Equine Performance Center, a state-of-the art equine sports and lameness facility at the Michigan State University College of Veterinary Medicine. It’s chock full of video equipment, sensors, high-tech saddles that need to be tested or patented, sensors, force plates, remote controls and did I mentioin sensors? There’s a feeling that if something is going to affect a change in the future for horses, its route passes through this building. You also have to wonder what the electric bill is. Everything plugs in and has a stand-by red light glowing in the dark. The sensors are always ready.

Across the parking lot looms the main vet college building and large animal hospital. You go inside and enter a labyrinth of corridors. You descend stairs. Pipes rattle. You walk down more hallways. Turn some corners. And at some point, you stumble into a place that is the antithesis of Dr Clayton’s futuristic electronic world.

You’re facing a mountain of coffin bones. Over here are some old farrier books, and through the microscope, you think you see what the classic professor Robert Bowker PhD DVM wants you to see, that a coffin bone can and does have evidence of osteoporosis.

In this lab, things pile up. They get dusty. The information is layered like the strata of a carefully dug herb garden. Deep historical reference compost and intellectual top soil combine here to make ideas grow. Theories and what-ifs sprout like weeds after a summer shower.

On weekends, Dr. Clayton's interest in dressage makes her showing schedule a living laboratory: she competes her horses unshod. Until last year, her veteran horse MSU MAGIC J competed at the grand prix level. Up-and-coming MSU FANFARE, shown here, currently leads the US Dressage Federation standings in dressage freestyle at second level. Both horses were bred by the university and selected by Dr Clayton for their movement characteristics, not their conformation. She looked for horses with good movement, instead of horses that looked like they could move.

Hilary Clayton calibrates a set of sequential video cameras and hits the “on” switch. Robert Bowker digs a little deeper, reaching for a certain specimen he knows is under the pile. He turns an idea around and realizes he forgot to stop for lunch. And that was hours ago.

Both these laboratories and both these professors study the horse’s foot...at the same university. Both are at the top of the game, and in spite of their proximity, they couldn’t be approaching the hoof from more different perspectives.

And what are the odds that if two professors at the same university were studying the same structure, they’d share a common point of view? Or that they could possibly collaborate on a research project?

College professors are often, by nature, protective of their turf. Someone else on the same campus studying the same thing should be a threat. But Clayton and Bowker have managed to put their well-stocked heads together on research for several years.

This week the latest product of their thinking-alike-but-acting-differently collaboration is a paper on how hoof morphology is influenced by a specific method of barefoot trimming. The paper was published in the Australian Veterinary Journal.

For anyone not familiar with the term, morphology is the study of shape, form and structure in nature. We use the word “morph” colloquially as a verb. When you “morph” into something else, you are changing shape or form.

Foot diagram for trimming protocol. The paper does not contain the word "breakover".

Make no mistake: this paper is not going to tell you how to rehab a horse's hoof. It is, however, going to give more credence to the idea that a specific method of barefoot trimming can successfully achieve a precise goal. Because it did, in the hands of Clayton, Bowker et al.

To be clear, Dr. Clayton is listed as the lead author, with Bowker's name fourth. His inclusion in the study is evident in the discussion section, where information on sensory nerves in the foot is shared. His inclusion also means the study is destined for wide readership among his many followers.

The paper begins with an important sentence that bears repeating. Memorize it: "There is little scientific data describing the effects of any type of barefoot trim, particularly in horses that participate in regular exercise in a riding arena, or how such trimming may affect the overall conformation and health of the foot for an extended period of time."

The problem: horses with mildly underrun heels. The goal: palmar/plantar migration of the heel area of the hoof, increase in heel angle and support length, and an increase in solar angle of the coffin bone. The hypothesis: it's possible.

Michigan State University's McPhail Center is where horses, data and electronics come together.

And not only is it possible, it's possible to do it with a rasp, not a wedge pad or a horseshoe. It's possible to do it so that the inside structures are not disturbed by cranking the hoof capsule into alignment in one shoeing, running the risk of creating separations and flares and adding strain to repositioned ligaments and tendons.

The research project achieved its goals, but it is important to note that this was achieved not by removing shoes, but by applying a specific trimming technique and repeating it, over and over and over.

In the end, the heel angle increased an average of almost nine degrees. The difference between toe and heel angle decreased from 13.8 to 7.2 degrees during the one-year maintenance period.

There are some key elements to this study that must be understood: The horses lived in a pasture, not in stalls. They received regular daily exercise (one to three hours) under saddle on a sand arena in a riding program five days a week. The horses were all Arabians of similar height and weight and age (average 13.6 years).

The horses in the study were barefoot before the research began, so they did not have to go through a transition-to-barefoot period. They were trimmed by one farrier (Cappi Roghan, who deserves some credit) throughout the study; he understood his assignment and acquiesced to stick to the program.

In the end, this study is not a victory for barefoot over shoes. This is a victory for showing that trimming alone can achieve a morphological change.

It just takes a lot of time, that's all.

The timeline of the study would not be considered a victory. It took four months of conscientious trimming to reshape the horses’ hooves, and then 12 additional months for the hoof to grow and stabilize in order to complete the study and prove the trim's effect. The authors felt that 16 months was required, based on the premise that a horse’s hoof grows an average of one centimeter per month, so that each horse, by the end of the study, would have had ample time to grow a completely new hoof.

The interesting aspects of the study are the way that the hoof morphology changed in one aspect then changed back. For instance, the area of the frog initially increased, then decreased.

The authors suggest that the horses’ feet at the beginning of the study illustrated the characteristics of wild horses living on soft sandy substrate, as documented by Brian Hampson PhD at the University of Queensland in his recently completed doctoral thesis, The Effects of Environment on the Feral Horse Foot.

The increase in toe angle during the initial transition period was an average of 2.7 degrees. Because this change was gradual, the authors commented that the trimming technique allowed the foot’s internal structures to gradually adapt, without any pathological consequences such as wall flares.

It should also be noted that the authors concurred that the goals of the trimming—palmar/plantar migration of the heels, increases in heel angle and support length, and increased solar angulation of the coffin bone -- are potentially beneficial to the health of the foot.

The key sentence to this study is found near the end of the paper: “Current knowledge of hoof structure and dynamics is incomplete and these ideas, while speculative, may provide a stimulus for further research.”

Note: The study was supported by the Bernice Barbour Foundation and the American Quarter Horse Association. The research team consisted of, in addition to Drs Clayton and Bowker, veterinary student Sarah Gray and MacPhail Center lab manager LeeAnn Kaiser.

Citation:

Clayton, H., Gray, S., Kaiser, L. and Bowker, R. (2011), Effects of barefoot trimming on hoof morphology. Australian Veterinary Journal, 89: 305–311. doi: 10.1111/j.1751-0813.2011.00806.x

Dr. Clayton on biomechanics of footing for dressage horses, part 1


Dr. Clayton on biomechanics of footing for dressage horses, part 2

To understand the full spectrum of hoof science, it is necessary to consider that it is much more than anatomy and physiology. The hoof is in motion, and how it moves affects its shape, its health and the relative condition of its components. Biomechanics means much more than trying to judge if a horse is landing heel-first or not.

You may need to adjust the volume on your computer. Watch as Dr. Clayton describes the mechanics of how the hoof of a dressage horse interacts with the arena footing. Filmed at the 2007 Adequan/ USDF Annual Convention in Orlando, Florida, this video is available on DVD with several other lectures on hoofcare and lameness from the USDF web site.

The abstract for this article is available online: The Australian Veterinary Journal: Effects of barefoot trimming on hoof morphology. You can also purchase a download of the complete article.

Click on ad image for details; image from Dr. Bowker's research at Michigan State U.

 © Fran Jurga and Hoofcare Publishing; Fran Jurga's Hoof Blog is a between-issues news service for subscribers to Hoofcare and Lameness Journal. Please, no use without permission. You only need to ask. This blog may be read online at the blog page, checked via RSS feed, or received via a digest-type email (requires signup in box at top right of blog page). To subscribe to Hoofcare and Lameness (the journal), please visit the main site, www.hoofcare.com, where many educational products and media related to equine lameness and hoof science can be found. Questions or problems with this blog? Send email to blog@hoofcare.com.  
 

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Robert Bowker Heads Down Under on Lecture Tour

One of Dr. Bowker's many beautiful macro images of hoof structures. This one, from 2003, was part of a study of the tissue of the bars in the heels, where the hoof walls hooks inward. Bowker studied the laminae of the bars and found migrating cells from the laminar tips in the bars contributing to growth of the sole. This research was presented at the American Association of Equine Practitioners Convention in New Orleans in 2003.

Robert Bowker VMD PhD will be headed to New South Wales in Australia next month to speak at a March 29- 30 workshop for professional hoof care providers and veterinarians who deal in barefoot rehabilitation.

Organizer Chris Ware said about the event: “Attending are professional trimmers some who are traveling from as far away as Western Australia, Queensland and the Northern Territory. It is fully booked already and we are looking forward to having a wonderful weekend with (Dr. Bowker), who is keen to present his latest research and explain how it relates to hoof care at the ‘coal face’.”

As part of the weekends lectures, Andrew Bowe "The Barefoot Blacksmith" will also talk about his work with seriously foundered horses. Bowe is a Master Farrier of 20 years experience who runs Australia's leading rehabilitation centre for foundered horses, according to Ware. Mike Ware of Easycare Down Under will talk on the many aspects of using Easycare’s range of hoof boots for the rehabilitation of hooves with serious issues and present the new range of boots.

All the proceeds from this workshop will be given to Dr. Bowker for his new research.

On the following Friday Professor Bowker is scheduled to teach the first module of a new Diploma course in Equine Podio-therapy course in Melbourne at the National College of Traditional Medicine. Other lecturers in Melbourne also include Bowe and Ware plus Dr. Alison Mcintosh (a veterinarian and equine chiropractor and barefoot trimmer who has long championed the cause of barefoot rehabilitation for serious hoof issues), and Wayne Anderson, also a Master Farrier, barefoot trimmer, and natural horse educator.

Dr. Bowker’s role in this course is largely due to the generosity of Easycare’s Garrett Ford who has kindly offered a grant towards Dr. Bowker’s nonprofit research.

Dr. Bowker, head of the Equine Foot Laboratory at Michigan State University's College of Veterinary Medicine is a consulting editor to Hoofcare and Lameness Journal, where many of his papers have been published, along with those of his former research colleague, Lisa Lancaster DVM PhD. Lancaster's histological studies from Bowker's lab on the crena of the white line appear in the upcoming issue of Hoofcare and Lameness.

Dr. Bowker and his microscope at home in Michigan.

Looking Back at 2007: This About Sums It Up, or: Israeli Vet Reminds Us Why We Are Still Just Spinning Our Wheels in Hoof Research

{Syndicated content copyright 2008 Fran Jurga's Hoof Blog and www.hoofcare.com}

"Incorporation of more advanced analysis systems in recent years has provided veterinarians with abundant new information related to the various effects of common shoeing and farriery techniques on foot and lower limb biomechanics. It is quite obvious however, that some aspects are still controversial or unclear. Among these controversies are the effects of change in heel height on the angles of the PIP ("pastern") and MCP ("fetlock") joints and on the strains of the flexor tendons and SL ("suspensory ligament").

"Comparisons of unshod and shod horses are rare, but the use of analysis systems, such as the pressure mat, may help to clarify debate about the purported benefits of shoeing horses versus leaving them barefoot. Fine (finite element) analysis of the distal limb seems to be limited by the complex anatomy. Indeed, it seems that a full understanding of the function of smaller structures, such as the distal sesamoidean or collateral ligaments, may only be achieved with the use of computer simulation.

"Finally, it should be noted that from an evidence-based perspective, most studies that have been performed evaluating the biomechanical effects of the common shoeing and farriery techniques have been performed using sound horses, and many others have been in vitro studies. Thus, although the information obtained from such studies is interesting, its direct clinical relevance is speculative and the strength of evidence is not as strong as is desirable. "

--from the summary of the paper "An Evidence-Based Assessment of the Biomechanical Effects of the Common Shoeing and Farriery Techniques" by Ehud Eliashar, BSc, DVM, MRCVS, published in Veterinary Clinics of North America: Equine Practice, in August 2007.

Translation: when it comes to hoof research, "evidence-based" is a relative term. The same sentiment was voiced at the Fourth International Equine Conference on Laminitis and Diseases of the Foot by Rustin Moore DVM PhD DACVS in his lecture "Evidence-Based Treatment for Laminitis".

For years, many respected voices have called for a standardizd protocol for foot research. We are expected to accept as gospel studies performed on treadmills. Bar shoes or wedges tacked on to only one front foot. Horseshoes nailed onto untrimmed, unbalanced feet. Shoes tested on ponies instead of horses. Raceplates on high-heeled non-racehorses. Shoes applied for testing without following manufacturer recommendations. And, in almost all studies, the lack of control data of the horse without shoes, or at least with normal flat shoes. Contrary data even exists as to whether horseshoes dampen or increase concussion.

Dr. Eliashar's paper points out changes in study results on the same condition when the horse is on a treadmill and controversies over interpretation of statistics on toe grab relevance in racetrack breakdowns.

Looking ahead, it makes sense to draw parallels between the struggles between Darwinism and creationism when comparing the arguments for the benefits of shoes vs natural (shoeless) trimming. When scientists like Eliashar and Moore are cautious about labeling existing scientific data as "evidence-based", the boat has some serious leaks.

For years, researchers like Chris Pollitt have asked, "How do you expect us to explain laminitis when we don't know how the normal foot metabolizes and grows and functions?" Researchers like Robert Bowker have mused, "I discovered this really interesting facet, but I don't know what it might mean..."

Kudos to those willing to admit that the function of the foot of the domesticated horse is still a mystery and that science doesn't have all the answers. Science may not have even been asking the right questions.

Happy new year, anyway!

Photo courtesy of Royal Veterinary College.

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