Horse running around a round pen

Horse sense

by Amy Painter

What makes Virginia Tech’s equine research program distinctive? Our people. We are proud to feature four uniquely specialized scientists who are at the top of their fields. Individually, they are as dynamic and diverse as they are accomplished. As a transdisciplinary team, they are leading a bold vision for Virginia Tech’s equine science program – one that offers students leading-edge research opportunities along with a contemporary and compassionate grounding in equine wellness and training. Meet the all-star team: Erica Feuerbacher, Sally Johnson, Robin White, and Caroline Leeth.

Sally Johnson works with two of her Ph.D. students, Nicolas Busse (middle) and Madison Gonzalez (right), to observe muscular development in horses after strenuous activity.

For Sally Johnson, “laboratory” is an expansive term. The researcher and horse enthusiast may often be found knee-deep in sawdust at one of the university’s barns instructing students in equine physiology. Then, there is the Middleburg Agricultural Research and Extension Center, where her duties include putting 14 off-the-racetrack thoroughbreds through their paces on a state-of-the-art treadmill. On the Blacksburg campus, in a more traditional lab outfitted with an array of high-tech microscopes, flasks, and flow cytometers, she investigates equine skeletal muscle growth and development. Each venue provides data that are central to Johnson’s efforts to accelerate horses’ recovery time following races and other strenuous activities.

The professor of animal and poultry sciences and Paul Mellon Distinguished Professor of Agriculture is internationally recognized for her work in adult stem cell biology. Now, she is equally proud of the multidisciplinary equine research team she has helped assemble – a team of like-minded horse enthusiasts, each with specialized skills and abilities, who are working and teaching together to support students and horses.

“The college’s equine research team offers a strong education component because we are trained in different disciplines,” said Johnson, who has been at Virginia Tech for seven years. “We love horses, and are all horse owners. Each of us can identify a strength and apply it to multiple species. And, because of our different specialties, we complement one another. That is the beauty of such a well-rounded group.”

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  • Virginia Tech's equine research team

    Virginia Tech's transdisciplinary equine research team leads a bold vision for the equine science program.

  • Virginia Tech's equine research team

    Virginia Tech's transdisciplinary equine research team leads a bold vision for the equine science program.

Johnson, a nutritional biochemist, and Caroline Leeth, a veterinarian and immunologist, work primarily with horses. Robin White, a nutritionist and modeling expert, works with cattle, sheep, and horses. Erica Feuerbacher, a psychologist, focuses on dogs and horses, and also holds an Extension appointment.

The team collaborates to design experiments and interpret results. As the senior member, Johnson is considered the leader and a trusted mentor, though she eschews the former designation. It is precisely her modesty, generosity, and desire to create a strong, egalitarian unit that contribute to the team’s strength and esprit de corps.

“The college has one of the larger groups of tenure-track scientists who work with horses,” said Johnson. “In addition, we are fortunate to be part of a larger university equine team with many colleagues who contribute to Virginia Tech’s research, teaching, and Extension mission.”

In addition to strong, long-term partnerships with immunologists, stem cell biologists, and other specialists in the Virginia-Maryland College of Veterinary Medicine, the foursome is aided by a supportive team within the college including Beth Sheely, equine science instructor, along with Natalie Duncan, who manages the two equine centers, coordinates more than 40 volunteers, and assists with classes. Youth Equine Extension Associates Sandy Arnold and Leona Ransdell provide 4-H instruction, aid in recruitment efforts, and play a vital role in the college’s research and equine-related projects.

“We count on them to help us with all aspects of the equine program,” said Johnson. “They are part of our decision-making processes that have to do with horses, classes, and programming.”

A growing program

Along with the state funding allocated for upgrading our animal facilities, we hope to leverage philanthropic support for further enhancements to the project. Our goal is to provide best-in-class facilities and state-of-the-art equipment for our teaching, research and outreach missions.

Plans are underway for


New stable for equitation horses

On-site equine laboratory and space for examinations

Recruitment of students and faculty

Renovations to Smithfield Farm and Campbell Arena

As a result, undergraduate and graduate students are able to understand the whole horse, and to gain both a practical and a scientific perspective.

“The students who come through this program are excited to learn about the horse, not necessarily just to ride,” said Johnson. “They want to understand what makes the horse work, and what makes the horse tick. Having students who are so eager to learn about nutrition, behavior, exercise, and immunology is rewarding. They are very engaged.”

In addition to her research responsibilities, Johnson serves as the graduate program director for the Department of Animal and Poultry Sciences. Both the size and overall quality of the department’s graduate program have increased since she became chair in 2014, and she has enhanced the recruitment of traditionally underserved and underrepresented students into the animal and poultry sciences graduate program.

Like her peers and many of her students, Johnson grew up with a love for horses. The Michigan native got her first horse at the age of 12, and has a quarter horse named Ziva in her backyard. Her daughter also rides.

Professionally, she is fascinated with skeletal muscle growth and development, and guided by a desire to understand how muscle repairs itself following a strenuous event such as a horse race.

“Muscle is very unique in that you can administer damage to it, and it will completely regenerate tissue loss because of stem cells,” said Johnson. “In people, stem cells become active within 24-36 hours after exercise. We see peak stem cell activity in horses about seven days after arduous activity. Horses are exercise machines, yet they take time to recover.”

With little information available on the cell biology behind horse muscle, the researcher is keen to understand how to control rates of recovery and how to use nutrition as a primary aid to expedite the rehabilitation process.

“It is a great opportunity to work in an area that is new and unique. Everything I’m learning has application to the industry, and it’s an industry I enjoy,” said Johnson, who has identified two promising supplements, known as nutraceuticals, that show potential to activate muscle stem cells and speed recovery. “That’s pretty rewarding.”

Part of White’s work focuses on work at the intersection of animals and big data.

During her five years at Virginia Tech, Robin White has taken a lead role in harnessing technological advancements that convert big data into practical applications for producers. Her research on horses, cattle, and sheep aims to better understand how livestock respond to feed and management in order to identify practices that are beneficial to animals, industry, and the environment.

White’s work with researchers at Purdue University and Pennsylvania State University on a “rumen robot” will help producers optimize animal health and reduce waste. Her leading-edge horse and cattle halter sensors are providing a big-picture perspective that is critical to the systems-oriented approach that governs White’s work. These projects have the potential to expand the SmartFarm Innovation Network and benefit not only the state’s livestock industry, but society as a whole. Learn more →

Feuerbacher (left) and graduate student Lindsay Isernia have been working with Dede, a mare prone to bolting from handlers. Now, the mare halters herself.

Erica Feuerbacher’s first horse was an off-the-racetrack thoroughbred mare with an unfortunate predisposition for bolting and depositing her 10-year-old owner into the uncompromising desert flora surrounding the youth’s Tucson, Arizona, home. Following a series of spontaneous “races” that did not end well for the rider, the mare was replaced by Ookie, an Appaloosa gelding whose engaging personality and gentle disposition solidified Feuerbacher’s affection for horses in general, and for the distinctive spotted breed in particular.

“If I knew then what I know now, I could have done a lot more for my thoroughbred mare and managed her behavioral issues better,” said Feuerbacher, an assistant professor in the Department of Animal and Poultry Sciences.

Like her Virginia Tech equine research colleagues, Feuerbacher has never been one to shy away from a challenge. During her first two years at Virginia Tech, the Extension specialist and animal welfare expert has made a name for herself partnering with canine rescue organizations along the East Coast to enhance the lives and adoptability of shelter dogs by establishing innovative and therapeutic overnight foster opportunities that have been proven to reduce the canines’ stress levels. Now, she is teaching Virginia Tech students to train horses using novel, positive reinforcement techniques that engage the animals’ innate perspicacity and problem-solving abilities.

While Feuerbacher’s demeanor is warm and patient, and her methods measured and heuristic, her approach is as progressive as her mission is ambitious. Through her research, teaching, and outreach, she aims to enhance the relationship between humans and animals to enhance our communication and understanding, one step at a time.

Feuerbacher (left) and graduate student Lindsay Isernia have been working with Dede, a mare prone to bolting from handlers. Now, the mare halters herself.

“In the equine world, we often ask the horse for more than they know. They don’t have the prerequisite skills, and this can be frustrating for both horse and trainer,” said Feuerbacher. “When this frustration arises, behavioral issues often crop up. My goal is to teach the student to ask for what the horse knows how to do, and then to gradually increase their skill set. This way, when we request a bigger behavior, the horse has the basis of understanding.”

As prey animals, horses are sensitive to all forms of pressure. They are also quick studies who learn by making associations between one thing and another. Breaking tasks down into small, measured steps is foundational to Feuerbacher’s work.

During her fall Equine Behavior and Training class, she taught 16 upperclassmen, all animal and poultry sciences majors, a sequential, patient, and practical approach to training. Over the course of the semester, the students attended a weekly lecture class and worked with yearlings at Smithfield Farm during labs held four days per week. Working in pairs, they introduced their yearlings to stimuli ranging from brushes and lead ropes to plastic flowers and tarps, taught them to lunge, and introduced them to tack, among other achievements.

“We start gently. We never put the horse in a position where it cannot give more than it’s capable of, or feels as though it cannot escape,” said Feuerbacher.

Haley Rae, a Massachusetts native who will graduate this year, took the class to learn new training techniques and to build her confidence working with young horses. The senior learned to deconstruct larger requests into small, discrete tasks – called shaping – in order to build her yearling’s confidence. For instance, when instructing her protégé, Aston, a good-natured chestnut gelding, to move at different gates, Rae first asked the yearling to move out to the rail, rewarding the behavior until he understood her request. Once Aston mastered this first step, Rae was able to move onto the next request, building on each over time.

“Horses are fast learners, and they take to rewards-based training. We see quick behavior change,” said Feuerbacher, who has successfully used rewards-based methods on her own horse, Magic, a spirited Appaloosa/Percheron gelding. “So much training is couched in the idea of using pressure, or negative reinforcement. However, changing this so the horse wants to work, and is not just escaping pressure, is really powerful.”

Using grain as a reward, Feuerbacher taught her students how to elicit affiliative behavior, in essence, motivating the horse to work, versus asking the animal to move away from pressure. She has found that horses respond well when they are earning something, and that they will work for a long time for a small food reward.

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  • Feuerbacher and a free lunging horse

    As Feuerbacher watches, Haley Rae free lunges Aston.

While inclusive of more traditional training methods, she wants her students to understand the science of behavior and to question “trainer lore,” some of which is unsubstantiated. The idea is that when students understand the science, their training can become more flexible. She notes that many in the companion animal industry are transitioning to positive reinforcement training, using rewards to offer animals an incentive.

“The methods I’m teaching are adaptive. Students are taught to adjust according to each horse’s needs,” Feuerbacher said. She and graduate student Lindsay Isernia are currently conducting applied behavioral research to explore the effects of different training methods on horse behavior, and the efficacy of different interventions on behavioral issues. In another study being conducted by graduate student JoAnna Platzer, Feuerbacher is examining the relative efficacy of different types of food rewards on horses. Undergraduate students, including Rae, also play an important role in this research; not only do some work as research assistants, their work with the horses helps Feuerbacher and her graduate students identify meaningful research questions from observing the horse-handler interactions.

“The most important takeaway I got from this class was to focus on working with the animal as a unique individual,” said Rae, who plans to work with horses professionally. “One behavior that’s exhibited in multiple horses, such as bucking, may be caused by different situations – so, there’s not one blanket fix. You have to find an individual solution for each horse by changing the reinforcers. My partner and I focused on rewarding Aston every time he exhibited the behavior we wanted with a reinforcer (positive reinforcement), and then revoking the privilege of the reinforcement if he didn’t exhibit the behavior we wanted (negative punishment).”

Rae and her classmates discovered that the training process requires patience, time, listening and observational skills, and a gentle touch. In addition, Feuerbacher’s methods place principles such as respect, and most particularly, trust, at the center of the human-horse relationship.

“When I think about trust, I think about saying something to a horse that means the same thing every time so that the rules are consistent,” said Feuerbacher. “So, if I allow a horse to graze while holding his lead rope, I can’t be angry when he equates the lead rope with the opportunity to graze. Trust comes from consistency – the animal knows the rules of the game, and the rules stay the same. That forces us to think about what we do and do not want to encourage in terms of terminal behavior.”


The methods I'm teaching are adaptive. Students are taught to adjust according to each horse's needs,  Feuerbacher said


Rae’s hard work was rewarded by mid-October, when Aston’s transformation into a well-schooled yearling was evident. While he will be used for Feuerbacher’s class again next year, the majority of the students’ yearlings were sold during October’s Hokie Harvest, with each pair helping to show their young trainees.

“Adding more tools in their toolkit is helpful. Now, when they face issues that cannot be resolved with traditional methods, they can be more flexible and adaptable, and work with horses who respond differently to different techniques,” said Feuerbacher. “Whatever fields the students choose, they will have to interact with animals, so understanding what controls behavior and how to effectively modify it, is really important.”

In the future, Feuerbacher would like to expand her classes to include more mature horses with behavioral issues. This dovetails with her shelter mission, which aspires to rehabilitate animals of all ages.

“We want our students to become good trainers, and the horses to gain meaningful skills. Meeting both of those goals can be challenging in the timeframe we have,” said the researcher, who also hopes to continue working with the Smithfield Farm yearlings. “My goal is to get both horses and students to a certain level simultaneously.”

Feuerbacher believes that behavioral problems stem from an animal’s inability to feel safe. Her own work with troubled horses has resulted in feats that many would consider miraculous. She and her graduate student Lindsay Isernia have been working with a mare named Dede who often bolted from her human handlers. Now, the mare halters herself and has learned to trust Isernia and Feuerbacher. At the end of the day, however, it’s about helping students transform their beliefs about animals, and about what is possible.

“Working with students and seeing the behavior change in their horses is always reinforcing. They are learning to teach in a way that gives horses a fair chance of getting it right, and offers instruction in a humane and effective way,” said Feuerbacher. “I always hope the skills they get from training, including compassion, empathy, and kindness, are attributes they will take with them and apply to any interaction they have. The training skills they learn are not just for horses, they are applicable to all species.”

Jing Zhu (right), an animal and poultry sciences Ph.D. candidate, works Leeth (left) primarily on systemic lupus erythematosus.

As a girl, Caroline Leeth enjoyed horseback riding during family visits to her grandparents’ farm. The Norfolk, Virginia, native began to ride more regularly during high school, and as a first-year veterinary student in the Virginia-Maryland College of Veterinary Medicine, Leeth bought her first horse at Hokie Harvest. She and VT Flexible “Flex” Flyer spent seven years together until injury forced the gelding’s early retirement.

These days, the equine enthusiast, researcher, and mother loves putting her Oldenburg, Gatsby, through his paces. She also enjoys riding in hunter competitions and watching her seven-year-old daughter, Eleanor, take up the sport.

Leeth received her Ph.D. in biochemistry and molecular biology from the University of Maine in 2011 through a joint program with the Jackson Laboratory, and her doctorate of veterinary medicine from Virginia Tech in 2001. Five years ago, she returned to Virginia Tech as an assistant professor of animal and poultry sciences.

Her research, role as equine committee chair, and partnerships across the university make her a crucial member of the college’s equine science team. She is also a double-hitter with a portfolio that includes both human and animal health. For the former, Leeth focuses on adaptive immune response in health and disease, and specifically the role of B lymphocyte maturation in two autoimmune diseases: type 1 diabetes and systemic lupus erythematosus.

For the equine component of her research program, Leeth and several fellow Vet Med immunologists and pathologists are working together to address equine protozoal myeloencephalitis, a serious pathogenic disease that can be debilitating to horses and ponies. By grafting the tissues of EPM-susceptible and EPM-resistant horses into mice, she is able to study individual immune responses.

“Horses who get sick appear to have a different immune response than horses that appear to be resistant, but this is difficult to study in the horse,” said Leeth. “We need control of environmental conditions, which is extremely difficult on a farm. For this reason, we use mice to model equine disease. We can study reliable data more efficiently. For EPM, this is important since this disease has lots of variability in response.”

In addition to understanding what makes certain horses EPM-resistant, the goal is to identify horses with a genetic susceptibility to the disease in order to take preventive measures.

“If we can identify horses who are vulnerable, we can put them on low-dose medication to keep them well,” said Leeth. “Current research with susceptible foals has shown that if their food is dressed with a low-dose medication, they remain protected from infection.”

Her work has also revealed that the organism that causes EPM hides from the immune system. Current medication used to treat this disease enables sequestration of the organism. When Leeth’s mice were taking the medication, they remained healthy, but once the medication was removed, they became sick.

In a new study funded by the Virginia Horse Industry Board, Leeth is investigating immune modulators designed to support the equine immune system. She is working with a drug available in Europe that shows promise in encouraging cells to secrete more protective interferon gamma in order to bolster immunity. Stay tuned.

“We hope this is just the beginning,” said Leeth.