What impact do structural deviations really have on your horse’s soundness and performance?
Good conformation is the foundation for good performance. Horses that are “well-built” and “put together correctly” are often among the top achievers in their sport. They also tend to bring higher prices or stud fees. For these reasons, horsemen and women are on a search to find prospects with “perfect” conformation.
Spoiler alert: The search could be futile. Perfect conformation is both a subjective assessment and rarely found, and even those horses built by the book can develop problems. And a horse with conformation faults can still be athletic and perform well with proper care.
“It’s a mistake to ignore conformational weaknesses, but it’s also a mistake to write off a horse that has one,” says Carol Gillis, DVM, PhD, Dipl. ACVSMR, owner of Equine Ultrasound and Rehabilitation, in Aiken, South Carolina.
Rachel Gottlieb, DVM, an associate veterinarian at Northwest Equine Performance, in Mulino, Oregon, a practice that focuses exclusively on lameness and performance horse issues, attests that, indeed, “buying a horse with nearly perfect conformation is not a guarantee that soundness issues will not arise.”
The severity of a horse’s faults and his age, breed, and discipline all factor into whether his performance is compromised.
“Many mild deformities are usually manageable, while a severe exhibition of the same deformity may be life-threatening,” says Josh Zacharias, DVM, MS, Dipl. ACVS, ACVSMR, who practices at Countryside Large Animal Veterinary Services, in Greeley, Colorado. “Many people think of conformation abnormalities as the worst they can possibly be, and that’s not usually the case.”
Riding discipline can influence a conformation fault’s degree of impact. A horse that is back at the knees, for instance, might not be a suitable racehorse or show jumper, but he could make a great hunter pleasure mount. Likewise, a horse with straight, posty hind-limb conformation might be prone to stifle issues and unable to perform well in events that require hard stops and turns, but he might be well-suited as a trail horse.
“I have seen an individual with a severe swayback win a 100-mile endurance race, while a lesser degree swayback in a jumper may lead to significant back pain,” says Steve Adair, MS, DVM, Dipl. ACVS, ACVSMR, CERP, director of the Equine Performance and Rehabilitation Center at the University of Tennessee’s College of Veterinary Medicine, in Knoxville.
While certain breeds can be prone to specific challenges, our sources caution against making sweeping generalizations about conformation.
“I do not think you can say that there is one conformation fault that is good or bad across all breeds or all disciplines,” Adair adds.
We asked these four sport horse veterinarians which conformation faults they consider most common, most manageable, and most commonly misunderstood. They picked seven structural deviations; here are their suggestions for assessing and managing them.
Carpus Valgus, aka Knock Knees
Carpus valgus is a turning-outward of the knees that can increase strain on the bones and ligaments on the medial (inner) part of the leg. Veterinarians and farriers can correct mild cases with hoof care and shoeing, while severe cases require surgery.
“These conditions are better managed in foals when the growth plate is still active, because the development of the bone can still be altered—either directly by surgical methods or in a more conservative fashion by using prosthetic applications such as corrective shoeing or splinting,” Zacharias says. “Adult horses that have a mild to moderate degree of the condition cannot be corrected and should only be managed.”
For these horses, management strategies typically involve trimming and shoeing. Your farrier will pay attention to the hoof’s breakover—the pivot point of the toe as the heels leave the ground—as well as its medial to lateral (outer) balance.
If a horse has a condition where the lower leg is not naturally perpendicular to ground, such as carpal valgus, a sole that is square to the leg axis would not meet the ground evenly. “I try to get the foot to land flat on the ground rather than the typical perpendicular orientation of the sole to the axis of the leg,” Zacharias explains. “This allows for more even distribution of forces from the ground up through the leg.”
Knock knees can interfere with the horse’s stride and also lead to arthritis development or secondary knee injuries, such as bone chips, from abnormal forces on the carpal bones. Veterinarians can often manage or treat horses with arthritis medically and surgically (debriding bone chips or damaged cartilage with the latter).
Most horses’ hooves are asymmetrical to some degree. One hoof that’s a drastically different shape than the others, however, can adversely affect soundness. An example of this is club foot, when the angle the face of the hoof wall makes with the ground is greater than 60 degrees.
Veterinarians can best manage, and even potentially correct, this abnormality in foals. First, they address any underlying problem, such as pain and reduced weight bearing. Then a farrier or equine podiatrist can add therapeutic trimming or shoeing.
“In neonatal and young affected foals, a treatment with oxytetracycline (an antibiotic with calcium-binding properties that relax muscles) can be implemented to help relax a tight deep digital flexor muscle/tendon unit that is often the cause (of the club foot),” says Zacharias. “More severe cases might require surgical transection (cutting) of the inferior check ligament or even the deep digital flexor tendon,” which runs down the back of the horse’s legs below the knee or hock.
It is more difficult to correct significant club foot in adult horses. Instead, veterinarians focus on reducing concussion on the toe of the coffin bone and lessening structural strain.
“I don’t try to make the foot look like the others. That too often leads to lameness,” says Adair. Instead, he trims each hoof in a way that lowers the heels to alleviate pressure on the coffin bone. He also applies special shoes or pads that can reduce tension on the deep digital flexor tendon and keep the toe and heel landing at the same time.
“If all the hooves are shod, I try to make sure the heels of the shoe do not stick out too far, which limits the chances the shoe can be stepped on and pulled off,” he says.
Typically, these horses require regular farrier visits spaced out over four-week intervals, because trimming too much, too quickly can become painful. “I don’t expect the heel height of the club foot to ever reach (lower to that of) a normal foot,” Zacharias says.
Over time, horses with a club foot that goes untreated or that fails to improve to a “normal” state might develop coffin joint pain. Your veterinarian can evaluate and address this with intra-articular treatments (joint injections), systemic joint therapies such as anti-inflammatories and disease-modifying osteoarthritis drugs (including injectables such as hyaluronate sodium or polysulfated glycosaminoglycan), or one of many oral joint supplements.
Long Back, Short Croup
Many Warmbloods and Thoroughbreds are prone to having this conformation, which increases the workload on the back because more muscle activity is required to lift the front end while working. This conformation is a benefit for certain athletes—it allows them to jump higher. But for this conformation to work for horses, they require proper strengthening or they might be prone to injury. “At the start of every ride, walk these horses for 15 minutes,” Gillis suggests. “This allows the joints (of the spine) to lubricate and signals to the horse’s system that it is time to work.”
You might also practice specific exercises designed to strengthen the horse’s back and croup, which, along with the muscles and joints of the rest of the spine, make up the horse’s core. Compression and extension exercises, such as frequent transitions from the walk to the halt, the walk to the trot, and the walk to the canter target the back muscles and strengthen the horse’s core.
Circles, especially spiraling circles that increase and decrease gradually in size, can also help these horses. Serpentines challenge the back muscles to perform laterally and help them become stronger.
For similar reasons, “bending exercises are also great,” Gillis adds.
Stifle Laxity, aka Loose Leg
Veterinarians sometimes attribute stifle laxity to the way a horse’s femur (“thigh”) and tibia come together—often in too straight of an angle. This can allow the medial patellar ligament to catch in a part of the medial trochlear ridge of the femur. Strengthening exercises are helpful for increasing stifle stability and ultimately improving weak hind ends. A combination of exercises in-hand and under saddle can improve these horses’ strength. “Tail-pull exercises, rounding exercises, and walking over raised poles are all beneficial,” Gottlieb says.
In addition to strengthening exercises, she notes some veterinarians might recommend therapies such as blistering or prolotherapy (injection of dextrose solution over the patellar ligaments to cause irritation).
“Blistering has fallen out of favor with some veterinarians due to the profound inflammatory response it induces,” she adds. “Prolotherapy is less widely recognized in the veterinary field, but has been used for years in human medicine and naturopathic medicine (for conditions such as tennis elbow and rotator cuff issues) to incite a healing response with a less significant inflammatory effect.”
If the laxity is causing a primary stifle joint soreness, the stifle joint itself might benefit from a therapeutic injection, but only after a careful physical exam, radiographs to rule out developmental orthopedic disease, and ultrasound if palpation indicates sore stifle ligaments. Again, in-hand and under-saddle exercises can help.
Low heels on the hind hooves can also aggravate stifle laxity, so have your veterinarian and farrier assess hind hoof balance.
Stifle laxity can indicate an underlying source of pain. For example, “We have had some horses with shivers tend to become sore in the stifles,” Gottlieb says. Your veterinarian can conduct an exam to rule these problems out.
Straight Hind Limb
Nearly any breed can have straight hind limbs, which predispose horses to suspensory ligament (which extends down the back of the lower leg between the cannon bone and the deep digital flexor tendon) injuries or degenerative conditions from repeated overloading. Horses that have straight hind limbs and long sloping pasterns or hyperextended fetlock joints are especially at risk for suspensory injuries.
“It’s a conformation abnormality that isn’t as widely recognized or regarded as a risk” as other faults, Gottlieb says. “It is a risk in many disciplines, but certainly for upper level dressage prospects,” as this discipline requires the horse to place more weight on his hind end. Movements such as piaffe and canter pirouettes, for instance, increase loading on the hind suspensory ligaments.
Leaving a straight-limbed horse barefoot behind can cause additional strain because without shoes, the heels might become so low that they cause undue tension on the already weakened ligaments and tendons.
“Hill work is contradictory to helping these horses,” Gillis cautions. “Even a 3% slope increases the strain on the stifle and suspensory ligament.” Instead, she recommends plenty of trot work on level ground to improve strength.
Toeing in, aka Pigeon-Toed
This conformation is most noticeable when viewing the horse from the front; one or both toes point inward. A horse that toes in swings his legs in a paddling motion in all gaits. As the horse increases his speed, however, the motion becomes less visible. Also, the more severe the toe-in conformation, the more severe the paddling or winging out.
“As a general rule, I consider toe-in conformation overemphasized,” Adair says.
This trait is undesirable in some disciplines, such as harness racing, because it typically causes the horse to slow down to avoid hitting his forefeet against one another (interfering). Owners and veterinarians can manage most pigeon-toed horses, however, to optimize their performance.
“In young individuals, I try to improve them with corrective trimming or shoeing. In more mature individuals, I simply trim/shoe enough to keep them from hitting themselves,” Adair explains.
He says he also finds that half-round shoes allow the horse to break over at the toe in whatever direction is most comfortable. Forcing a correction, on the other hand, can put too much torque on the distal (lower) limb and lead to lameness.
Toeing Out, aka Splay-Footed
Again, this deformity is best visualized from the front. It can originate as high as the shoulder or hip, as well as in the lower limb, and as the limb advances it wings out.
“Usually, toe-out conformation is not a big issue and can be overly criticized,” Adair notes. “If the horse is not interfering or hitting himself as his legs swing inward, I do nothing.”
In cases where the abnormality interferes with the horse’s stride, he focuses on moving the breakover slightly to the inside toe. If that doesn’t work, he says he lightens up the medial branch or bevels or rolls the edge of the shoe from the medial quarter (inner side of the hoof wall) back to the heel.
What Does it All Mean?
Conformation certainly influences a horse’s athletic achievements, but it’s not the only ingredient for success. Many factors, including talent, will, and training, contribute to performance.
“What’s most important is to recognize a weakness and then take the steps necessary to help the horse achieve its fullest potential,” Gillis says.
Horses with mild conformational faults will potentially experience added stress or wear-and-tear on their bones, joints, and supporting soft tissues. “Owners need to be willing to address those areas through preventative measures such as icing, wrapping, diligent shoeing, systemic joint supplements among others before it becomes a full-blown lameness issue,” says Gottlieb.