8 Most Common Injuries in Endurance Horses: Risk Factors, Treatment & Prevention

Unlike the explosive speed of racehorses or the poised collection of hunter-jumpers, the endurance horse has a more specialized skillset. Endurances horses – and riders – work hard to go the distance.

Riding in the range of 80+ kilometers (50+ miles) a day over variable terrain requires long-term physical preparation and a steady mental commitment.

Like all equestrian disciplines, endurance riding comes with a unique set of risk factors for specific injuries that can affect a horse’s performance and overall health.

Read on to learn more about the risks and common equine injuries associated with endurance horses. Understanding these issues and how to prevent and manage them can help ensure a stress-free ride for horse and rider alike, keeping everyone on course for as long as it takes.

Impact of Endurance Riding on Horses

Endurance is not for the fair-weather rider. While many equestrians spend time training or in competition for an hour or two at a time, endurance races have winning ride times in the range of 14 to 15 hours.

From its humble origins in American long-distance travel, equestrian endurance riding is one of the fastest growing disciplines worldwide. According to the Fédération Équestre Internationale (FEI), in 2023 there were nearly 800 international endurance events. ^[1]

Horse (and rider) welfare is paramount in endurance riding, and safety pervades all aspects of the sport. One national organization that governs long-distance riding in the United States is the non-profit American Endurance Ride Conference (AERC).

Their motto, “to finish is to win,” reflects the endurance riding community’s emphasis on maintaining a healthy horse over measures of speed or individual placings. ^[2]

In spite of having a robust culture of safety, endurance, like all sports, carries risk of injury. One study found that approximately 75% of endurance horses studied over a ten-year period sustained at least one orthopedic injury during training or competition. ^[3]

The most common injuries in the study group were localized to the following regions of the horse’s body: ^[3]

• Fetlock Area: 27.1% of injuries
• Proximal Metacarpal Area: 21.4%
• Foot: 21.1%
• Tarsus (Hock): 12.8%
• Midportion of the Metacarpal Area: 9.1%
• Other sites: 8.5%

As expected for horses traveling at speed over distance, the shock-absorbing structures of the musculoskeletal system are most vulnerable to injury.

Ride Cards & Endurance Horse Safety

The AERC and other regulators of endurance riding typically use a ‘ride card‘ system that scores individual horses against veterinary criteria. Ride cards are populated with health-check data for each horse before, during and after the event.

A large survey performed by the AERC of ride cards revealed that lameness was the single biggest factor for removal from the race, a designation called ‘failure to quality.’ ^[4] In most cases, symptoms can be assigned to front (45.9%) or hind (23.4%) limb.

Since in-field tests for soundness are performed in a relatively quick manner and without full diagnostic equipment, a more robust diagnosis of the underlying causes during competition is usually not feasible.

Where in-field lameness is localized, the symptoms typically involve points that are most vulnerable to strain, torque and bruising – namely, the muscles, tendons, ligaments, joints and hooves. ^[3][4][5]

Risk Factors

Studies of race-collected data have identified risk factors as predictors of injury in racehorses. Identified risk factors include: ^[5][6][7]

• The horse and rider’s age
• Average speed during competition
• Level of competition
• Fore limb conformation
• Amateur status of the trainer and rider

Endurance horses may likewise experience metabolic disturbance associated with dehydration and fatigue, as well as sensitivity in the saddle and girth regions. ^[4]

Horse-Related Factors

First and foremost, it’s important to ensure equine endurance athletes are good candidates for the sport. Keeping horses in disciplines they are physically well-suited for is the first defense against injuries.

Factors to consider for endurance horses include: ^[7][8]

• Breed: Arabians and cross breeds of Arabian influence are common in the sport. Arabians are thrifty breeds valued for their history of long-distance travel in hot, arid climates.
• Age: Typically, horse athletes are in the 8 – 12-year-old age range but, like other disciplines, older horses can compete and excel against their younger counterparts. One study found competitive endurance horses older than nine years are more likely to suffer from lameness and metabolic issues.
• Conformation: Some horse body types are better suited to the unique demands of endurance riding. Conformation faults in your horse, especially in the forelimbs, can increase the risk of inefficient movement and injuries.

Ride-Related Factors

Equestrian endurance sport has humble origins but is now popular at a global level. As for other FEI disciplines, the levels (or ‘stars’) of endurance events are rated based on difficulty. One-star (1*) events are the least difficult and 4* and 5* events are the most difficult.

Event difficulty is influenced by

• Environmental conditions
• Air quality
• Terrain
• Length of the course

More difficult events pose a higher risk of injury to human and equine participants.

Rider-Related Factors

Rider status and gender may affect the risk of injury or onset of metabolic issues in horses during endurance rides, though the reasons are not always clear. ^[3][7]

Intro to Equine Nutrition

Gain a deeper understanding of your horse's nutrition needs. This free introductory course provides a foundation for horse owners to learn how to balance your horse's diet.

Enroll Now

Top 8 Sports Injuries in Endurance Horses

While there aren’t detailed studies available to pinpoint exactly which types of injuries are most likely in endurance horses, the physiological demands of long-distance riding put substantial strain on the musculoskeletal system. Here are some of the most common injuries associated with competitive endurance riding.

1. Exertional Rhabdomyolysis

Exertional rhabdomyolysis (ER) or ‘tying up’ affects up to 4% of horses participating in 50-mile (80 km) distance events. ^[9] This exercise-induced condition can arise from over-exertion of the large muscle groups of the hind end, back or neck.

Early signs of ER include: ^[10]

• Stiffness
• Behavioral signs of stress
• Shortened stride
• Reluctance to move
• Excessive sweating

Overtraining or mismanaged exercise routines, including abrupt changes in exercise intensity, can trigger single or recurring episodes of this painful condition.

Endurance horses afflicted by ER may be prescribed a combination of rest and fluids. Dietary adjustment to replace fluid lost in sweat along with pain relief and muscle relaxants may be prescribed. ^[10] Massage therapy may also help alleviate pain and stress directly at the source.

Management and prevention strategies include:

• Gradual conditioning with sufficient rest and recovery between training sessions
• Maintaining hydration before and after exercise
• Ensuring a balanced diet with sufficient electrolyte supplementation

Strains and Sprains

Like the human endurance runner, repetitive concussion on bones and strain on muscles can lead to injury.

2. Suspensory Desmitis

Suspensory desmitis involves injury and inflammation to the suspensory ligament, which can affect both fore- and hind-limb. ^[4]

Since the suspensory ligament supports the fetlock during movement, endurance horses may be most vulnerable when riding in soft, deep footing where fetlock joints lose support from the ground. Desmitis can also arise from twisting of the lower limb when a horse lands on uneven ground.

This injury is suspected based on palpation of the limb to reveal sensitivity or swelling and is confirmed by diagnostic imaging, such as ultrasound. Further, diagnostic nerve blocks may help localize the injury. ^[4]

Recovery can vary but for endurance horses with mild desmitis and no changes seen on ultrasound (i.e., a simple strain) the prognosis is good. ^[4] With stall rest, localized cooling, hand walking and a gradual return-to-work plan, recovery can progress over weeks.

Severe cases that involve partial or complete tearing of the fibres of the ligament or, worse, detachment of ligaments from the bone require extensive rehabilitation. Recovery in these cases takes months and prognosis is more guarded. ^[4]

Chronic or recurring cases of suspensory desmitis can affect the long-term working career of the horse.

3. Acute Joint Sprain

The repetitive stress of long-distance riding makes endurance horses prone to acute injury from joint sprains. Even a careful horse and rider can misstep due to overexertion or fatigue leading to improper joint stabilization on stride.

As expected, the fetlock joints, which are subject to significant weight and impact, are vulnerable to sprain in the endurance horse, as are coffin joints, which are located within the hoof. ^[4]

An acute joint sprain is a traumatic injury, but proactive care, including proper nutrition and conditioning provide the best circumstances for a worry-free long-distance ride. ^[8]

Bruises and Laminitis

The repetitive impact placed on the lower limbs is an inescapable aspect of endurance riding. This impact is associated with bruises and other traumas to the hoof and heel.

4. Hoof Bruises and Heel Bulb Trauma

Riding asks a lot of hoof and heel, and they require a lot of attention. A seemingly small injury that is precisely located on sensitive parts of the foot can derail a horse for days or longer.

Many hoof and heel injuries are diagnosed quickly with a hoof tester at endurance checkpoints.

If hoof bruises are superficial then they may resolve with minimal intervention. Keeping the injury covered with a wrap or cushion, and free of infection, is key for a timely recovery. ^[4]

Special boots and farriery can help a horse avoid hoof and heel injury, and may be tailored to the individual horse’s conformation and the ground type expected for training and competition.

Some options that endurance riders may consider with their farrier to help reduce the risk of bruising or other avoidable traumas include:

• Choosing the right shoe
• Fine-tuning the angle of impact
• Using special equipment such as bell boots, sole pads or barred shoes

5. Acute Concussive Laminitis

Under the hooves’ hard exterior are soft, finger-like protrusions called laminae that bind the hoof capsule to the coffin bone deep inside the horse’s hoof. ^[4]

On hard surfaces or under repetitive impact, the sensitive laminae can sustain damage, leading to inflammation of this tissue, or laminitis. The inflammation in turn can weaken the connection between the capsule and the coffin bone, leading to instability and severe pain. ^[4]

Illustration: Dr. Ana Mesa, PhD

The onset of laminitis in endurance horses can be sudden. Symptoms may include: ^[4]

• Increased temperature of the sole, wall and coronary band
• Signs of acute pain, especially if walked in a tight circle
• Behavioral changes like anxiety
• Sweating,
• Shortness of breath
• Reluctance to move

Treatment of acute concussive laminitis varies depending on the case, but may include: ^[4]

• Stall rest
• Anti-inflammatory medications
• Reducing pressure on the foot
• Icing
• Corrective shoeing

Prevention includes: ^[4]

• Feeding a well-balanced, digestible diet
• Avoiding excessive work on hard surfaces
• Ensuring proper foot care
• Managing the horse’s workload

Persistent Injuries and Chronic Pain

As endurance horses train and compete, they are always exposed to some risk of injury. Even without clear injury recorded on a ride card during a race, the effects of wear and tear can accumulate in tissue. This can lead to long-term or persistent injury, even far removed from any race itself.

6. Superficial Digital Flexor Tendonitis

The superficial digital flexor tendon (SDFT) is load bearing and highly prone to injury in performance horses. Strain on the SDFT can cause tendonitis (tendon inflammation) with significant consequences, including long recovery times and risk of recurrence. ^[4]

As with other forms of repetitive strain injury, adjusting your training and management choices are the best prevention. Strategies to minimize the risk of tendon overload include:

• Effective, safe training regimens: gradually increase the intensity and duration of exercise
• Surface management: where possible, use solid and stable surfaces to train
• Monitoring and adjustments: track your horse’s body condition and ensure they are carrying an appropriate amount of weight for their age, health status, and level of work
• Rest and recovery: allow tissue to heal between intense training and competition
• Supportive training equipment: consider supportive wraps and boots
• Leverage expertise: work with qualified equine professionals, including trainers, farriers, nutritionists, and veterinarians, to ensure you are making well-informed management decisions

7. Knee and Hock Arthritis

Osteoarthritis is one of the most common causes of musculoskeletal pain and lameness across all types of competition horses. It is a progressive condition that can lead to permanent joint deterioration and can limit a horses’ career. ^[4]

The horse’s knee and hock absorb shock from the body weight and motion. As horses age, these joints often deteriorate as the cartilage and other connective structures degenerate. This leads to increased friction within the joint space, causing pain and inflammation. Eventually, permanent bony changes occur which can compromise range of motion. ^[4]

The risk of arthritis is heightened for endurance horses where the physical demand on these joints is high.

8. Splints

Younger horses with developing bones and tissue are more vulnerable to the effects of concussive impact on the forelegs, but splints can arise from trauma to the interosseous ligament in any horse. ^[4]

The initial injury manifests as heat, inflammation and lameness. Over time, the injury hardens into a bumpy mass that is a calcification of the affected splint (metacarpal) bone. ^[4] When splints harden, they are easily felt by running a hand down the horse’s inner leg over the splint bone.

The repetitive impact of endurance riding, particularly to the front legs, can predispose the endurance horse to splints, especially if the horse has conformation faults. ^[4]

In most cases the prognosis is good. Many horses live and work with visible splints without a disruption to their normal work routine. ^[4]

Preventing Injuries in Endurance Horses

To prevent down-time for your endurance horse, consider implementing the following strategies:

• Develop a deliberate warm-up and cool-down routine to get muscles warm and flexed before your ride, then get those same muscles cool and loose afterwards.
• Plan to build fitness gradually with a progressive training program that balances intensity and duration of workouts.
• Work with a qualified trainer to develop your horse’s endurance training program.
• Diversify training to include a variety of exercises that develop overall fitness and strength for (you and) your horse.
• Routinely examine your horse for early signs injury or illness. Do not continue training if your horse seems unwell and contact a veterinarian promptly at the first sign of pain or lameness.
• Where possible, train on surfaces that provide adequate support and cushioning. Avoid deep sand, as it may increase the risk of some common injuries noted above, like suspensory desmitis.
• Learn to identify when your horse is becoming fatigued during competition or training. Pushing an exhausted horse increases risk of injury.

Finally, regardless of your discipline, one of the most important aspects of your horse’s athletic performance and injury prevention is robust nutrition. Ensure your horse receives a balanced diet with adequate nutrients to support training, recovery, and bone and joint health.

If you are not sure your endurance horse is getting everything they need to go the distance, work with a qualified equine nutritionist who can analyze your horse’s feed regimen no matter their age, health status, or sport.