4 injuries to watch for in Western performance horses

Western performance horses are a diverse group of equine athletes trained for a variety of disciplines with unique physical demands.

“The ‘Western performance horse’ is such a vast, encompassing topic,” says Vern Dryden, DVM, CJF, who owns Bur Oak Veterinary & Podiatry Services, in Lexington, Kentucky, and breeds and shows reining horses.

One thing they have in common—from roping horses to reiners, gymkhana speedsters to cow-cutters, and everything between—however, is they’re all at risk of injury as a result of the stresses their work places on them.

Flexor Tendon Injuries

The superficial digital flexor tendon (SDFT) runs down the back of the horse’s leg from just above the knee or hock to the pastern. The deep digital flexor tendon (DDFT), located beneath the SDFT, runs from above the knee or hock, down the back of the leg, and around the fetlock, attaching to the bottom of the coffin bone within the hoof. Our sources say injuries to these structures are common in Western performance horses.

When problems arise above hoof level—think the classic bowed ­tendon—horses become lame suddenly. The tendon swells, sometimes immediately and other times over 12 to 24 hours, Bell says. These horses are painful to palpation.

“The SDFT tends to tear in the lower third of the tendon and just above the fetlock at the back of the cannon bone,” he says. “The DDFT tends to tear in the upper two-thirds of the tendon at the back of the cannon bone, or below the fetlock along the back of the pastern. Both tendons can also sustain tears as they run through the tight channel at the back of the fetlock between the sesamoid bones. This will result in marked swelling/­effusion (fluid buildup) of the flexor tendon sheath.”

Tendon injuries within the hoof might be less obvious visually, but horses generally still become lame.

How they’re diagnosed

Bell says practitioners conduct a lameness exam and use ultrasound to diagnose DDFT injuries above the hoof. If horses are at a clinic, MRI and tenoscopy (inserting a fiber-optic camera beneath the skin to explore the tendon in the anesthetized horse) can also be useful diagnostic tools.

When a veterinarian suspects an injury within the hoof, Dryden says the first step is to use a nerve block to localize the lameness; the horse goes sound when the affected region is numbed.

“Imaging is the next step,” he says.

Dryden says ultrasound is useful unless the injury is inside the hoof. “With most of the injuries (below) the heel bulb, you end up having to do an MRI.”

This, he adds, often reveals other findings. “It’s not usually just a DDFT injury,” he says. “You usually have inflammation of the navicular bursa (which cushions the navicular bone), impar ligament, suspensory ligament at the navicular bone—it’s myriad issues that come along with it because it’s all tied together.” 

How they’re treated

“Minor tendon injuries can be managed with rest, ice, anti-inflammatories, and compression/wraps and will resolve in a short time period,” Bell says.

He stresses that veterinarians should always ultrasound suspected tendon issues throughout the healing process because swelling can subside in as little as two weeks, potentially giving a false sense of healing.

“Horses that are returned to exercise during this time period develop much more severe tears and in some cases breakdown injuries,” he says. 

Moderate to severe flexor tendon tears can benefit from shock wave, vibration, laser, and other adjunctive therapies, Bell says. Regenerative therapies—­including platelet-rich plasma (PRP) and stem cells—can also aid healing, he adds.

Within the hoof, “if the lesion is significant enough and it’s in an area you can access it, intralesional treatment with PRP and/or stem cells is great,” Dryden says. “Many times, we’re ‘calming down’ everything around it, so we’ll end up treating the navicular bursa and/or the tendon sheath.”

He also recommends working with a farrier or equine podiatrist to adjust the horse’s shoeing regimen.

“Shoe them in a way to take tension off the deep flexor tendon, remove lever from the toe (so, bringing the breakover point back toward the center of rotation), elevate the heels slightly, and, possibly, unload the center of the foot with a V-pad (which covers the sole but not the frog). Sometimes, putting pressure on the frog can create pressure on the lesion on the deep flexor tendon that extends over the navicular apparatus.”

Post-treatment Dryden recommends rehabbing horses with a controlled exercise program, which can include traditional in-hand, ponied, and ­under-tack exercises, as well as treadmill work and water exercise. He also recommends treating the horse with hyperbaric oxygen therapy (HBOT) if available.

Bell says rehab program structure is very important and should be monitored by the veterinarian throughout the five to nine months typically needed to heal these tissues.

Prognosis

Depending on the injury’s severity and how well owners stick to the treatment and rehab plan (and how the horse tolerates it), Bell says the prognosis for returning to soundness is fair to good.

Dryden adds, “Anytime we have a true core lesion (essentially, a hole) on the deep flexor tendon, I worry about return to full athletic abilities. But we see a lot of deep flexor tendinopathies that are inflamed but not necessarily a tear that do quite well with rehab and treatment.”

Stifle Injuries

Bell says he often sees stifle injuries in mature working horses.

“These horses will develop acute, severe lameness in the hind end, which will gradually improve over three to seven days following the injury, but distinct lameness will remain,” he says.

The affected joint often swells, and the horse is painful during joint flexion and extension.

“The horse will stand and walk with the leg abducted (held out from the body) and foot turned out from the body, and the affected limb will have a shortened stride,” Bell says. “A hip-hike lameness (the hip on the lame side pops up higher than the other when viewed from behind) is often observed, and the lameness may appear worse with the lame leg on the outside of the circle at a trot.”

How they’re diagnosed

Veterinarians conduct a lameness exam, looking for evidence of joint effusion, using joint manipulation (evaluating how the stifle functions when it’s extended beyond its normal physiological limits), administering a joint block to localize pain, and imaging the region (generally radiographs and ultrasound, sometimes nuclear scintigraphy, and, if it’s available for use on stifles, CT and MRI). Surgeons might also make a definitive diagnosis via stifle joint arthroscopy, Bell says.

How they’re treated

Treatment depends on the injury’s cause and severity. “Acute, traumatic injuries not affecting the soft-tissue structures within or stabilizing the joint can be managed with systemic anti-inflammatories and rest,” Bell says.

If injuries involve those soft-tissue ­structures—such as the cruciate ligaments, collateral ligaments, or meniscus within the stifle—treatment is generally more complex and might also include:

• Cold therapy or icing, and/or
• Ultrasound- or arthroscopic-guided PRP, interleukin-1 receptor antagonist protein (IRAP, a biologic therapy), or stem cell injection.

Ultimately, Bell says, arthroscopic surgery might be the best bet so the surgeon can identify and address all the issues during the procedure.

Post-treatment, he recommends rehabbing horses with a controlled exercise program that might include traditional in-hand, ponied, and under-tack exercises, as well as treadmill work and water exercise. He also recommends seeking HBOT, if available.

Prognosis

While it depends on the injury’s cause and severity, affected horses generally have a fair chance to return to soundness, Bell said.

Hock Osteoarthritis

Commonly affected joints in Western performance disciplines include the lower (distal) hocks, pasterns (in a condition also known as ringbone), and stifles; here, we’ll focus on osteoarthritis (OA) in the hocks, which is a frequent problem in all disciplines.

Our sources say many horses with distal hock OA exhibit poor performance and/or a shortened or stabby gait.

“They’re not wanting to get down and follow the calf, or they’re not getting into the ground when they’re stopping if they’re a reiner, or they’re not wanting to stop with the calf on a tie-off,” Dryden says. “All those are indicators that ­something’s going on—they don’t have to be overtly lame.”

Bell adds that there might be heat and/or bony swellings on the inside of the leg at the lower hock joints, as well as a pain response to palpation.

“When the limb is flexed for the hock, the lameness will become apparent or be exacerbated,” he says, and “there may be decreased range of motion of the hock joint.”

How it’s diagnosed

Often, a lameness exam (including longeing), flexion tests, nerve and joint blocks, and radiography are sufficient to diagnose OA. In some cases veterinarians might use more advanced imaging, including CT, MRI, bone scans, and PET scans, says Bell.

How it’s treated

At its simplest, treatment consists of anti-inflammatory drugs and a reduced exercise program for a time. If that isn’t effective, joint injections are a frequent next step.

“Typically, I’ll treat these with a steroid and hyaluronic acid (HA),” Dryden says. “DepoMedrol (methylprednisolone, a corticosteroid) and Hyvisc (HA) is what I typically use.”

Bell adds, “Steroids typically take around 10 to 14 days to have effect and usually last for six to nine months … ­alleviating lameness symptoms.”

He says veterinarians also use IRAP and PRP injections, as well as shock wave therapy, to combat distal hock OA.

Our sources agree that joint fusion might be the best bet for managing severe distal hock OA cases.

“Fusion of the joint results in relief of pain from arthritis with a small loss in torque transfer motion in the lower hock,” Bell says.

Surgical fusion is also an option. However, surgery poses its own limitations, including cost and anesthesia risks, and in recent years veterinarians have instead explored using ethyl alcohol to hasten the fusing process, called ­ankylosis.

“Veterinarians can inject alcohol—­sterilely and very technically—into the joint spaces of the distal hock joints, which denatures the cartilage (alters its properties) and allows them to fuse,” Dryden says.

Bell says fusion occurs over four to six months after surgery or four to 12 months following alcohol injection.

“Once they fuse and there’s no more movement in those joints, they’re sound,” Dryden adds.

Prognosis

Caudal Heel Pain

While not necessarily related to sport itself, Bell says caudal heel pain (localized to the rear or back part of the horse’s hoof) is more common in Quarter Horses and stock breeds than in the general equine population.

The challenge with this condition, Dryden adds, is the multitude of structures that could be affected, including the:

• Navicular bone and/or bursa (collectively the navicular apparatus);
• Suspensory ligament near where it connects to the navicular bone;
• DDFT;
• Impar ligament;
• Extensor tendon; and
• Coffin joint (where the coffin bone, navicular bone, and short pastern meet).

“The horse will be described as having a shuffling gait, ‘sore in the shoulders,’ shortened stride, tripping or stumbling, and may prefer to stand with one of the feet ahead of the other or with the heel elevated,” he says. “The horse is visibly sore at a trot, most commonly.”

Caudal heel pain typically only affects the forelimbs, Dryden says, and commonly both at once.

How it’s diagnosed

In addition to a lameness exam, veterinarians can use hoof testers, nerve blocks, and imaging (radiographs, ultrasound, and MRI) to diagnose caudal heel pain, Bell says.

Identifying all the structures involved allows more targeted treatment and helps improve the chance of a successful outcome.

How it’s treated

Initially, treatment involves corrective shoeing to shorten the toe, ease breakover, and support the heels to avoid their contraction, Bell says.

“Anti-inflammatories are used concurrently with the shoeing to decrease inflammation and allow for better comfort while adjusting to the new foot angles and trim,” he adds.

If that doesn’t provide desired results, veterinarians might opt to inject the coffin joint and/or navicular bursa.

“Injections can be with hyaluronic acid, corticosteroids, IRAP, platelet-rich plasma therapy, or, in advanced disease including the coffin joint osteoarthritis, polyacrylamide gel,” Bell says. “Shock wave therapy can also be effective in modulating caudal heel pain and ­inflammation for a period of time.”

He adds that horses with navicular bone cysts, bone loss, or bone edema (fluid buildup) diagnoses can ­benefit from a class of bone drugs called ­bisphosphonates.

If those treatments aren’t effective, surgeons can perform bursoscopy (placing a small arthroscope into the navicular bursa) to assess and debride lesions and adhesions. 

Following treatment, Bell says, rehabilitate horses with traditional in-hand, ponied, and under-tack exercises as they slowly return to work, along with treadmill work and water exercise, if possible. Hyperbaric oxygen therapy can also help.

“In horses where all surgical and medical treatment options have failed, a palmar digital neurectomy (cutting the palmar digital nerve to desensitize the foot) can be considered,” Bell says.

“This is a salvage procedure (meaning the horse might only be pasture sound), and nerve regrowth does occur typically over two to five years,” he adds, meaning repeat surgeries might be required.

Prognosis

Depending on disease severity and how well horses respond to treatment, they have a fair to good chance of returning to soundness, Bell says.

However, “horses with flexor surface erosion, ulceration, and/or loss of the navicular bone (visible) on radiographs tend to have a poor prognosis to return to soundness,” he says.

For Best Results …

Regardless of your horse’s injury, the following steps are key to giving him the best chance at returning to full use or soundness:

• Get a proper diagnosis, Dryden says. It might be a time-consuming and pricy endeavor but, chances are, it’ll be less expensive in the long run if your veterinarian knows what you’re dealing with.
• Follow your veterinarian’s instructions and recommendations to the best of your ability, Bell says.
• Have patience. “If you don’t give them enough time and you bring them back to work too early, you’re going to make it worse, and then you’re starting all over again,” Dryden says.
• Listen to your horse, Bell says. “Don’t push him through discomfort, and recognize fatigue,” he says. If you think something isn’t right or his condition is getting worse, call your veterinarian.
• Work closely with your horse’s health care team—your vet, farrier, trainer, and anyone else involved in providing care—during treatment and ­rehabilitation.

Prevention Is the Best Treatment

While you can’t prevent every injury, you can reduce your horse’s chances of sustaining one.

Be sure your horse is fit. “An unfit or fatigued horse is at high risk for injury,” Bell says. “A person would not decide to head out and run a marathon or sprint a 100-meter dash without conditioning for that level of exercise,” so don’t expect your horse to, either.

“Not having a horse fit, pulling them out of the stall, going to the show pen and being a rock star for five minutes, and then not having your horse because he’s injured isn’t worth it,” Dryden says.

And, even if your horse is well-­conditioned, know when enough is enough.

“Horses often have their injury toward the end of a ride—fatigue is a major contributor to injury,” Bell says. “The rider should learn to recognize when (the) horse is fatigued,” and call it a day.

Don’t overwork your horse on ­repetitive-motion exercises. “You can cause a lot of trouble by overusing these horses, especially longeing them,” Dryden says. “I think a lot of horses are broken because they’re being overlonged, getting them quiet.”

Sure, a horse needs to learn the barrel pattern and how to work a cow, but once he knows his job, don’t drill him on the same movements repeatedly. Also, avoid overlongeing, Dryden says. Vary your conditioning and training rides to help avoid repetitive-use injuries.

Feed your horse properly. “Appropriate nutrition for the level of work and conditioning is very important,” Bell says. Horses lacking adequate nutrition will become fatigued faster.

Keep your horse on a consistent farrier schedule. “A long toe can do a lot of damage, especially on a performance horse,” Dryden says, noting that a long toe compounds the load on soft tissue structures in the hoof already under heavy stress.

Have your horse trimmed and/or reset every four to six weeks. This might vary slightly among individuals, so work with your farrier to find the ideal schedule for your horse.

Also, resist the urge to delay appointments, even if it doesn’t look like your horse has grown much foot. Even subtle changes in hoof angle can affect the mechanics within, which can put your horse at risk for injury.

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