Editor's note: This article is part of TheHorse.com's ongoing coverage of topics presented at the 2012 International Society of Equitation Science conference, held July 18-20 in Edinburgh, Scotland.
In a world where "sustainable" has become a million-dollar buzzword, some horse owners might be on the lookout for ways to create sustainable equine athletes. According to a British equitation scientist, if we pay attention to certain details--like good conformation, good footing, progressive training programs, well-rounded exercise programs, body condition, and subtle signs of lameness--we can help our horses enjoy longer sports careers.
"Musculoskeletal injury is the most common cause of days lost from work and horses lost, in all equine sports," said Sue Dyson, MA, VetMB, PhD, DEO, FRCVS, head of Clinical Orthopaedics at the Animal Health Trust in Newmarket, England. "I believe the prevention of injury and early recognition of injury are key for a sustainable athlete, both physically and mentally."
"Prevention" includes recognizing conformation problems that are risk factors for lameness, Dyson said during a lecture opening the 2012 International Society of Equitation Science (ISES) conference, held July 18-20 in Edinburgh, Scotland. Recent research has shown, for example, that horses taller than 170 cm (16.3 hands) have a 15% greater risk of becoming lame than horses 163 cm (16 hands) or shorter. Additional research has shown that taller horses also end up with shorter competitive careers.
Horses with straight hocks have a greater risk of ending up with injuries to the suspensory ligament in the back legs, Dyson said, as do those with hyperextended back fetlocks.
Paying attention to foot conformation is particularly important, Dyson said, as foot pain is the source of most kinds of lameness. Front feet should be symmetrical--meaning the left side should look like a mirror image of the right side. If it doesn't, the horse is a candidate for lameness.
And this is something that can be somewhat controlled by good breeding since foot asymmetry is, to some extent, heritable, she said. In other words, before breeding, check the sire's--and the mare's--feet for symmetry first. It's also worth noting that asymmetry in lame horses can get more obvious with age, and horses that have it statistically end up with shorter athletic lives.
"This is something we can recognize very early on in a horse's career," Dyson said. "Has it got asymmetrical front feet? If it has, it's more likely to leave the competition arena sooner."
Even the shape of the coronary band can tell a lot about a horse's potential for developing lameness, Dyson said. Straight coronary bands are better than curved bands, but evenly curved bands are better than unevenly curved bands. Getting even more technical, researchers have also discovered that certain angles involving the coronary band height, the hoof wall length, and the heel length will also predispose a horse to lameness.
Footing plays an important role in keeping horses sound, Dyson said. Good footing should allow the toe to sink in while still providing good, strong support and resistance to the hoof.
Wax-coated and sand-and-rubber surfaces yielded the fewest lame horses in her studies. Sand alone led to an increased risk of tripping, and wood chips were more likely to cause slipping. Regardless of which surface, however, maintenance is critical, she said. If the ground is patchy or uneven normally and then gets muddy when wet or hard when hot and dry, you're more likely to see lameness.
"Ground that was uniform in normal and hot or dry conditions was associated with decreased risk of lameness," she said.
Young horses should be worked on a gradual scale to get progressively more fit as exercise increases, as repetitive overuse injuries are common in high-level sport horses just entering training, Dyson said. Know the horse you're working with and his abilities and limitations, she advised.
Also, trainers should vary the kinds of training, which is good for the musculoskeletal system as well as the horse's mental health and skills, Dyson said. Jumping horses should be doing some dressage work, but dressage horses should also be doing some jumping and even working on varied terrains. Trail riding is good, too. They also need turnout time for free-range exercise for their physical and mental well-being, she added.
Body condition is a key factor in sustainability as well, she said. The trend nowadays is to keep horses too heavy. More and more competition horses are having body scores of around 4 on a 5-point scale, she said.
"We have become accustomed, very sadly, to expect that this is the normal body condition score for horses; this is not," she said. "It is vitally important that we re-educate ourselves to avoid this." Excess weight can cause too much loading on limbs and can also lead to weight-related conditions such as equine metabolic disease and laminitis.
Finally, trainers and riders need to be on the constant lookout for early signs of lameness, Dyson said, in order to treat the condition as soon as possible. While this might be a limp, it might also be much more subtle. A change in performance, saddle asymmetry, a resistance to working in a certain direction or on a certain rein, tension in the back, fighting with the bit--these could all be signs of lameness.
By giving horses with these kinds of problems a temporary nerve block in a suspected limb, Dyson confirmed lameness in horses that seemed otherwise sound. "It is often possible to completely transform a horse's way of going by eliminating apparently low-grade pain," she said.
Above all, Dyson said, people need to know what's normal and not normal for their horses. If they can get used to what their horse's legs, body, and mind feel like when healthy and sound, then they'll be more likely to recognize when something is off. It's recognizing--and acting on--these changes that will help keep horses sustainable over the long term.
Disclaimer: Seek the advice of a qualified veterinarian before proceeding with any diagnosis, treatment, or therapy.