Veterinarian, researcher, and author Hilary Clayton has forever altered our understanding of sport horses
By Kelly Vencill Sanchez
Reprinted from the July/August 2021 issue of USDF Connection magazine
If you have even a passing interest in sport-horse performance, rehabilitation, and conditioning or the impact of tack and equipment on horse and rider, chances are you’ve come across a study by Hilary M. Clayton, BVMS, PhD, Dipl. ACVSMR, FRCVS. Over the course of a career that’s seen her combine her talents as a veterinarian, college professor, and researcher, she has published more than 250 scientific studies, lectured at symposia and conferences around the world, and written seven books and hundreds of articles for magazines including USDF Connection.
At Clayton’s induction into the Roemer Foundation/USDF Hall of Fame at the 2020 Adequan®/USDF Annual Convention last December, British FEI 5* dressage judge Stephen Clarke recalled (via virtual video clip) her “Biomechanical Perceptions of Dressage Performance” presentation at the Africa Dressage Forum in Johannesburg two years before: “The way you can manage to put across what could be pretty complicated stuff in such a clear, easy-to-understand manner has brought a light into many areas of the sport,” he said.
That ability to break down complex scientific ideas into manageable parts is one of Clayton’s gifts, says Michigander Mary Anne McPhail, who, with her husband, Walter, endowed the Mary Anne McPhail Dressage Chair in Equine Sports Medicine that Clayton held at Michigan State University from 1997 to 2014.
“I’ve read a lot of Hilary’s research that goes to her peers, and I don’t know what she’s talking about—it’s over my head,” admits McPhail, who is a retired USEF “S” dressage judge and a longtime adult-amateur rider and competitor. “But when she talks to us, we get it. She can put it on a level that everyone can understand.”
Finding practical applications for her investigations has always been important to Clayton. “It’s not much good sitting in my lab where nobody else can see it,” she says. “It sometimes takes a while to make the leap from the scientific publication to the practice in a way that people can actually use. You do science at different levels.”
A secret to Clayton’s success might well be that she doesn’t observe horses only from the sidelines. She’s an experienced horsewoman, having competed in eventing, jumping, cutting, and combined driving. She’s earned her USDF bronze, silver, and gold medals and hopes to move her 13-year-old Lusitano gelding, Donzi MC, up to Intermediate I later this year.
Clayton’s experiences in the saddle and her regard for horses inform her research and vice versa. “I’ve always been interested in conditioning horses, how to make them fit for the job they’re going to do,” she says. “Learning about the biomechanics has given me more ideas about how to develop exercises to get horses fitter.”
A Growing Passion
Nothing about Clayton’s early life growing up as the eldest of two children in the English town of Matlock, Derbyshire, presaged her later achievements. Her father was an accountant, her mother a teacher, and Clayton was the only one in her family with any interest in horses.
Still, on visits to her mother’s family in southwestern Scotland, there was the chance to ride along the Firth of Clyde. “For sixpence, you could ride a pony about 50 yards with somebody leading it down the beach and back,” Clayton remembers. “I would pester my parents all day long for another sixpence for another pony ride.”
Her horse-obsessed prayers were answered when she was 10, when a riding school rented a field behind Clayton’s house, and one day she looked out to see it populated with ponies. “I would spend as much time with them as I could, talking to them, petting them, feeding them,” she says. “On Saturday mornings, they went off to be riding-school ponies for the weekend.”
Eventually she got her parents’ permission to follow them, which meant a three-mile walk each way. The cost for a lesson was three shillings, but Clayton’s pocket money was only two shillings. To make up the difference, she fetched groceries for a neighbor: “As long as I walked both ways, I had enough money to ride for half an hour.”
Foreshadowing her later passion for dressage, not content just to hack around the countryside, Clayton decided to train herself. “I would take whatever horse I got that week and just ride circles with no stirrups. I didn’t do it very well, but I always wanted to be better.”
At 12 she joined the High Peak Pony Club. “We lived in an area where all the fields were divided by stone walls, so we’d jump those,” she recounts. “For me, it was always, ‘That’s a bigger wall than I’ve ever jumped—wouldn’t it be great to jump it?’”
During her time in Pony Club, Clayton was like a sponge, absorbing everything she could and filing it away for the future. “I would read and memorize every book about horses that I could get my hands on. I think the more you know, even though it might not seem relevant at the time, someday it’s going to be useful.”
From there she began competing in cross-country competitions and eventing, and dreamed of a career in veterinary medicine. “I really liked biology in school,” she says. “My parents would have liked me to have gone into medicine, but the only way I could see going to university and staying close enough to horses was to do veterinary medicine.”
At that time, veterinary practice was a predominantly male domain, but the lack of role models didn’t deter Clayton from entering the University of Glasgow’s famed veterinary college in 1968. “People tried to steer me away from going to vet school because they knew how difficult it would be for anybody to get in, and especially for a woman.” She smiles. “But I was determined.”
She found ways to ride while immersed in her studies, jumping horses for a local riding school and teaching riding lessons on weekends. She also served as captain of the university’s equestrian team. “I took advantage of every opportunity,” she says. “Sometimes it was a matter of creating opportunities—going out there and saying, ‘Have you got any horses I could train?’”
A Dream of Working with Sport Horses
Clayton was newly graduated from vet school and working at a mixed veterinary practice in southwest Scotland when a thought nagged at her.
“I had this idea that I wanted to work with athletic horses, not just racehorses, which is mostly what we had in the practice,” she recalls. “I wanted to understand how sport horses functioned and use that to train them better and keep them sounder. It was just a vague thought at the back of my mind because nobody was doing it.”
Not only was nobody doing it; the field of equine sports medicine wasn’t yet a specialty. Still, Clayton returned to Glasgow University to earn her PhD in equine parasitology while concurrently working as an assistant professor in anatomy.
A fateful moment occurred in 1979-80, when Clayton accepted a one-year position as a visiting professor at Michigan State University, East Lansing. Her timing couldn’t have been better. The late Violet Hopkins had just begun holding national seminars for dressage instructors at her Tristan Oaks Farm outside Detroit, a program that paved the way for the USDF Dressage Symposiums, the USDF FEI-Level Trainers Conferences, and the USDF Instructor/Trainer Program. Clayton also met someone who would become a lifelong friend: dressage instructor and judge Maryal Barnett, who lived in the East Lansing area.
“Vi was very determined that Americans would learn to do this dressage stuff properly, and she would bring in European trainers,” Clayton says of Hopkins. “Maryal and I used to drive once a week to Vi’s place, and I would get a lesson. After that, Vi invited me to speak at some of her seminars.”
At one of those seminars, Clayton attracted the attention of someone else who would figure prominently in her life: Mary Anne McPhail. “I can’t recollect what Hilary spoke about, but I remember being very impressed with her intelligence and the substance of her presentation,” McPhail says.
Returning to Glasgow, Clayton had her sights set on finding a job in the US when a post teaching anatomy at the University of Saskatchewan’s Western College of Veterinary Medicine came up. “I thought, ‘Oh, a stepping-stone into the States,’” Clayton says. “I was there for 15 years.”
Though it might not have been part of her original plan, the job afforded Clayton the opportunity to delve into the kind of research in equine biomechanics that interested her. Other opportunities arose. Clayton, who was a certified British Horse Society instructor in the UK, got involved with Canada’s fledgling equestrian coaching program, for which she later became an instructor and examiner. The need for information about equine exercise physiology and equine-conditioning programs for coaches inspired her first book, Conditioning Sport Horses.
Clayton’s interest in combining her love of sport horses with equine sports medicine continued to grow. “In the beginning, sports medicine wasn’t really medicine at all,” she explains. “The people who really got equine sports medicine going in North America were the endurance riders.
“It was all sort of a meeting point,” she adds. “I always wanted to ride and be a part of horses, and from there I wanted to be a veterinarian. And here was this whole new world just beginning to open up that brought together all my interests. It was the perfect place for me to go and move forward.”
While in Canada, Clayton began doing more dressage and also earned her judges’ cards for dressage, jumping, and hunters. She also met the man who would become her husband, Richard Curle.
“We met through a mutual friend,” Clayton remembers. “We were taking her children to the local ski hill, and Richard joined us. He’s an expert skier and I’m terrible.” (Skiing may be the one thing Clayton doesn’t do well.)
Right Place, Right Time
Clayton’s next professional opportunity saw her return to Michigan, when she became the inaugural McPhail Dressage Chair at MSU. McPhail says she had no doubt that Clayton was the right one for the job.
“Naturally, we wanted the best to represent us, and I knew I wanted Hilary. She has such a curiosity. And once she got to Michigan State, there were so many things she wanted to investigate. We’ve all learned so much from her research in sport-horse mechanics, the interaction between horse and rider, and the effects of various rehabilitation techniques. Hilary is one of a kind.”
During her time at MSU, Clayton established close ties with the school’s prestigious Arabian breeding and training farm, and she encouraged the start of its dressage training and competition program. “I’d never had an Arabian, but I was impressed with their quality as sport horses,” she says.
One day, a small, plain gelding caught her eye. When she saw his student rider having trouble making downward transitions and getting him to stand still, Clayton got on to see if she could help. “It was love at first ride,” she quips. “My assessment of his problem was that he was simply an overachiever, which suited me just fine.”
The horse was MSU Magic J, named for the university’s famed alum, basketball star Magic Johnson. Clayton purchased him a year later as a nine-year-old and began competing him at Training and First Levels. Seven years later the pair went down center line at Grand Prix. Together they earned her USDF bronze, silver, and gold medals as well as numerous national awards, both in the Arabian division and as a USDF adult amateur.
When Clayton retired Magic from competition, she donated him back to MSU, where he resumed his career as a school horse.
Making Life Better for Sport Horses
FEI 4* dressage judge Lois Yukins, who chairs the USDF L Education Program, remembers seeing Clayton in the show arena: “She was riding the Michigan State Arabs and doing a wonderful job.” After seeing one of Clayton’s lectures, Yukins recommended her as a speaker to then-L program head Marilyn Heath. Clayton began sharing her knowledge with USDF-certified instructors as well as with the L program faculty.
“Hilary would bring in judging concepts and biomechanics concepts,” Yukins recalls. “She talked to us about the back, the legs, the hooves, bitless bridles, the thoracic sling, and the nuchal ligament, as well as how horses propel themselves and carry weight. She’d say, ‘You can’t just focus on the hind legs. You have to focus on why the horse can’t use the front legs correctly in order to rock back.’ One year she brought boxes of bones so that she could show us the horse’s back. She’s been so generous, and she went above and beyond to help us.”
Yukins credits Clayton’s input with improving the USDF L program as well as the US Equestrian judge-licensing programs: “Hilary made sure our comments made sense and that they were actually true. She really wants to make it better for the horses, and she can’t do that without the people understanding. If the only influence of judges is their words, then their words ought to be correct.”
Her Next Chapter
Clayton, now 71, retired from Michigan State in 2014 after what she calls 17 “glorious” years. “Strangely enough, my days are not very different from when I was working except that I work at home and nobody pays me anymore,” she says with a laugh. “I still do what was always the most fun part of my job, which is transferring knowledge through writing and speaking, and this past year making webinars.”
While she enjoys having the time to tend the garden at the Michigan home she shares with Curle and their rescue dog and cat, and to volunteer at a local cat rescue (kitten-hugging is a favorite pastime), anyone who has worked with Clayton knows that taking it easy isn’t exactly her style. This past winter, during her annual pilgrimage to Florida, she balanced her own training and competing schedule with her continuing research on what she calls the Florida 2020 Project: Data collected by a team of researchers from the UK, the Netherlands, and Sweden from 20 dressage horses in Wellington is being analyzed both by computers and by a group of FEI dressage judges organized by Yukins.
Explains Clayton: “We hope to teach the computer to recognize the different gaits and movements and to detect the qualities associated with high and low scores from the judges.” This summer, her team will also undertake an in-depth analysis of the counter-canter—how it differs from the true-lead canter, as well as the effects of turning radius on mechanics, how much horses lean into the turn, and comparisons between the canter leads and directions.
Another summer project—this one with UK-based equine-biomechanics researcher Dr. Sarah Jane Hobbs—will look at the piaffe. “We’ll study the horse’s balance and how exactly they adjust the angles in the fore and hind limbs to change the degree of uphill balance,” Clayton says. “I think this will have an impact on our understanding of how to teach horses the essential skills needed to perform a good piaffe.”
As she has been doing for nearly 25 years, Clayton writes articles for the USDF’s magazines detailing her research findings. Her contributing editorship began with “The McPhail Chair Report” in Dressage & CT in the late 1990s and continues today with her periodic “Sport Horse” reports in USDF Connection. Her groundbreaking equine-biomechanics findings—including the discoveries that the piaffe lacks a moment of suspension and that the canter pirouette is not three-beat—forced dressage traditionalists to reevaluate their old textbooks and even prompted the USEF Dressage Committee (now Dressage Sport Committee), of which Clayton is a former member, to rewrite descriptions of these gaits and movements in the USEF Rule Book. And her insights into the effects of footing, bits, saddles, rider position, and more on dressage horses’ performance, health, and soundness have led to changes in materials, designs, management, and even riding and training theory.
The sport of dressage, Clayton hopes, will embrace what the science can demonstrate.
“We’re not trying to prove anybody wrong or change the sport,” she says. “We’re trying to analyze what the sport is now and how you can treat the horses to keep them sounder and get them fitter and have them performing better.”
Clayton pauses to reflect on the fact that having cutting-edge technology to perform such calculations was unimaginable when she was starting vet school.
“I don’t think it would have been possible when I was 18 to say that I want to do what I’ve done because it didn’t exist at the time. You have to take your opportunities—with both hands.”
Kelly Vencill Sanchez is an award-winning writer based in southern California.