The young horses at this Lusitano farm in Brazil are well-conditioned for their future athletic careers, thanks to full-time turnout on varied terrain and good genetics.

Photo: Courtesy Dr. Hilary Clayton

Horses are products of their genetics and the environment we provide for their growth and development. One of the most important choices we make when managing horses during the first few years of their life is whether they are stabled or turned out, and for how long. Different types of exercise are necessary to stimulate adaptation of the different locomotor musculoskeletal tissues (bone, articular cartilage, muscle, ligament, and tendon), and these tissues are most responsive at different ages. Therefore, young horses need a sufficient amount of appropriate types of exercise at the right times in their lives to fulfill their athletic potential and reduce their risk of injury.

Researchers have shown that 24-hour-a-day turnout during the early months of a foal’s life is the gold standard for developing a strong, resilient locomotor system. Management approaches in which foals are kept in stalls even for part of the day are less effective in stimulating optimal locomotor tissue strength. This is especially true for the superficial digital flexor tendon (which runs from the back of the knee [or hock] all the way down to the back of the pastern in each limb and acts as a “sling” to support the fetlock to help it bear the animal’s weight) and the suspensory ligament (which runs down the back of each cannon bone). Both structures are frequently injured in equine athletes. These soft tissues reach their maximal strength by the time the horse is 2 years of age, ­after which they are no longer able to adapt to the stimulus of conditioning.

Another benefit of turnout relates to a horse’s development of surefootedness. Turnout stimulates the proprioceptors (sensory mechanisms that tell the horse where his feet and body parts are) in the hooves, joints, muscles, and tendons that provide information about the body’s position and movements. The neuromuscular system responds to the proprioceptive information by causing appropriate body and limb movements. Ideally, during their first two years, horses should be exposed to different types of footing and terrain to enhance their proprioceptive awareness and hone their reflex responses so they can adapt to uneven ground without ­tripping or stumbling.

If our goal is to produce horses that are athletically talented and sufficiently resilient to withstand maximal competitive efforts, there is no substitute for a natural upbringing with full-time turnout on varied terrain.

Having retired from my academic position as Mary Anne McPhail Dressage Chair in Equine Sports Medicine at Michigan State University, with the intent of devoting more time to riding, I’ve recently been horse shopping. In addition to looking for a young horse with good conformation and movement, I’ve wanted a horse that has grown up in a natural environment with plenty of activity early in life. I was thrilled to find just such a horse in dressage trainer Jorge Gabriel’s barn in Tyngsboro, Mass. Jorge had imported several young Lusitanos from a farm in Brazil, where the young stock run out on large pastures on a steep hillside. Through a combination of good genetics and appropriate management, these horses have developed good bone; strong, well-developed feet; and they already look like future athletes. I’m now the proud owner of a lovely 3-year-old called Gajo Santana, who I hope has the appropriate foundation to succeed in a dressage career.


Hilary M. Clayton, BVMS, PhD, Dipl. ACVSMR, MRCVS, is Professor and Mary Anne McPhail Dressage Chair Emerita at Michigan State University, and President of Sport Horse Science LLC, based in Mason, Mich.

Originally published in the June 2014 issue of The Horse: Your Guide To Equine Health Care.