12 Most Common Injuries in Racehorses: Risk Factors, Treatment & Prevention

Horse racing is a thrilling sport, demonstrating the power and speed of equine athletes performing at their absolute best.

From the raw speed and acceleration of Quarter Horses, to the impressive stamina of Thoroughbreds, to the jumping ability of National Hunt horses, horse racing has something to offer for every horse enthusiast.

However, the extreme forces placed on the horse’s body at high speeds makes them susceptible to injury and lameness. Not only do these injuries affect the horse and their welfare, they also have economic impact on the breeders, trainers, and racetrack officials managing these athletes.

Read on to learn more about the most common sports injuries that racehorses experience, including how they are treated and the long-term effects on the horse’s racing career. By understanding these injuries and how they occur, racehorse managers can protect their horses’ safety and longevity in the sport.

Impact of Racing on Horses

Racing asks horses to perform at their maximal effort, resulting in extreme concussive forces and strain on soft tissues and bones. The front limbs are particularly affected, due to bearing the horse’s weight and momentum during the “down” phase of the gallop. ^[1]

The equine limb adapted during evolution to maximize speed and economy of movement, rather than strength or resilience of the structures. ^[2] Their limb mechanics are also relatively fixed, with minimal adaptation to different environments, ground surfaces, or other conditions that may affect performance. ^[2]

The combination of these factors predisposes horses to injury during high-speed movement, particularly over long racing careers.

As expected based on their evolutionary biology, racehorses have a high rate of lameness due to the concussive forces experienced during racing. One study shows 20% of racehorses in England developed a lameness issue that prevented a return to racing. ^[3]

Additionally, around 80 – 83% of equine deaths associated with racing and training are due to musculoskeletal injuries. ^[3]

This high rate of lameness not only affects the horses themselves, but also has economic consequences for horse breeders, trainers, and racetracks. ^[3] This is a driving force behind the significant ongoing research into the major risk factors, causes, and preventative measures for racing-related lameness conditions.

Risk Factors for Injury

Several studies examined risk factors for sports injuries in racehorses, particularly catastrophic breakdowns that are frequently life or career-ending. Commonly identified risk factors for racehorse injury include: ^[1][3][4][5]

• Age: Overall, the severity of injuries is similar for all ages of racehorses. However, certain injuries are more common at certain ages. For example, bucked shins are more common in young horses.
• Gender: Geldings have a higher risk of fatal injury than females or stallions.
• Race level: Horses in the lowest levels of racing have a higher risk for injury.
• Hoof conformation: Low heel angles or underrun heels have a higher risk of suspensory injuries.
• Shoeing choices: Using toe grabs on horseshoes may increase the risk of injury.
• Racetrack surface: Surfaces that are “fast”, hard with little give, or poorly maintained increase the risk of injuries.
• Race length: Longer races may increase the risk of injuries.
• Field size: The number of horses in the race may increase the risk of injury.
• Previous starts: Horses who have had more racing starts may have a higher risk of injury.
• Time since previous start: Horses who had time off prior to a race may be more likely to experience injury.

Top 12 Most Common Sports Injuries in Racehorses

The most common injuries observed in racehorses are similar between different breeds of horses, including

• Thoroughbreds
• Standardbreds
• Quarter Horses
• Arabians
• National Hunt Steeplechase horses

All of these injuries reflect the strenuous nature of horse racing which pushes horses up to, and sometimes beyond, their physiologic capability.

Hoof Region

Hoof pain is one of the most common causes of racehorse lameness, particularly in Thoroughbreds. ^[1] These conditions result from the continual pounding of the hooves against the racetrack surface, leading to concussive injury to the tissue. ^[1]

1. Hoof Pain

Common causes of hoof pain in racehorses include: ^[1]

• Bruised heels or quarters
• Hoof abscesses
• Quarter cracks

Bruises and cracks are a direct result of concussive force. In the case of hoof abscesses, damage to the tissue allows dirt and bacteria to infect the hoof capsule, producing an abscess. ^[1]

Most horses recover from these conditions quickly with appropriate treatment, such as: ^[1]

• Shoeing changes to redistribute weight or reduce concussive force
• Draining hoof abscesses
• Patching cracks in the hoof wall with resin or acrylic

Fetlock Region

During racing, horses place their entire body weight on their front limbs, putting extreme forces on the fetlocks. This repetitive strain can cause degeneration of the tissues over time, potentially resulting in sudden tissue failure. Horses may also develop osteoarthritis as their body attempts to repair damaged tissues.

2. Synovitis

Synovitis refers to inflammation of the joint capsule, resulting in swelling and pain when using the affected joint. ^[1] The inflammation likely develops due to repetitive stress on the soft tissues during training. ^[6]

This condition is most common in young horses, and usually resolves on its own if horses are given time off of racing and training to heal. ^[6]

Treatment for this condition involves: ^[6]

• Stall rest
• Icing
• Bandaging
• Anti-inflammatory medications

Some veterinarians recommend joint injection with anti-inflammatory medications or other products to promote healing. ^[6]

3. Sesamoid Bone Injuries

The sesamoid bones, located at the back of the fetlock, are under tremendous strain during weightbearing. ^[6] This strain can result in inflammation of the sesamoid bones and its surrounding soft tissues (sesamoiditis), or fracture of the sesamoid bones. ^[6]

Treatment for these conditions typically involves: ^[6]

• Rest
• Anti-inflammatory medications
• Surgical correction of fractures if necessary

The prognosis depends on the severity of the condition. Most sesamoiditis cases recover quickly with appropriate treatment and continue their racing careers. ^[6]

For sesamoid fractures, the location of the fracture, which sesamoid bone is affected, and whether it is a front or hind limb dictates prognosis. ^[6] Some horses successfully return to racing careers after sesamoid fractures. ^[6]

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Cannon Bone Region

The cannon bone region bears many of the mechanical forces during racing, particularly the cannon bones of the front limbs. Therefore, this is a common location for lameness to develop in racing athletes.

4. Third Metacarpal/Metatarsal Bone Disease

Third metacarpal/metatarsal bone disease refers to mechanical stress-related injury to the cannon bone. ^[1] In particular, the dorsal aspect (the front of the bone) is commonly affected due to bending forces exerted when the horse bears weight on their limb at speed. ^[1]

Most cases are mild, with horses showing signs of lameness despite no bone changes on X-ray. ^[6] Race trainers call this condition “bucked shins“, and it occurs from the pain associated with thickening of the bone as it repairs small microfractures. ^[6] Lameness typically resolves quickly with reduced exercise and pain control. ^[6]

In severe cases, third metacarpal/metatarsal bone disease can lead to saucer fractures of the cannon bone. ^[6] These cases require surgical correction and prolonged stall rest to allow the bone to heal. ^[1] Affected horses frequently develop recurrent lameness issues that prevent further racing careers. ^[1]

5. Suspensory Desmitis

Suspensory desmitis refers to inflammation of the suspensory ligament and is a frequent cause of lameness in racehorses. This condition occurs due to the high forces the suspensory ligament experiences during weightbearing, resulting in strain and irritation of the tissues. ^[1]

This condition is most common in young racehorses, however it can occur in racehorses of any age. ^[1] Racing on synthetic surfaces may increase the risk of suspensory desmitis. ^[1]

Horses with suspensory desmitis typically have a good prognosis, and many can be managed to continue racing while their ligament heals. ^[1]

Treatment involves a combination of: ^[1]

• Anti-inflammatory medications
• Rest
• Icing the limb

6. Splints

Splints, or exostoses of the splint bones, are a common cause of lameness in young racehorses. ^[1] In this condition, inflammation or irritation of the splint bones or surrounding soft tissues results in pain and bone deposition in the area. ^[1]

Poor conformation or hard track surfaces may predispose horses to developing splints. ^[1]

Treatment focuses on reducing inflammation through icing, poultices, and anti-inflammatory medications. ^[1] Horses often require periods of rest before returning to training and racing. ^[1]

7. Superficial Digital Flexor Tendonitis

Superficial digital flexor tendonitis refers to inflammation of the superficial digital flexor tendon. ^[1] This condition is common in all types of racehorses, however it is most common in National Hunt horses who jump over steeplechase fences during their race. ^[1]

Initial treatment typically involves anti-inflammatory medications and icing the limb. ^[1] Some veterinarians recommend surgical intervention or injection of medications into the tendon during the treatment process. ^[1]

Most horses require a long period of rest, up to 12 months, before returning to training and racing. ^[1] Around 40% of horses reinjure their tendon after returning to exercise. ^[1]

Knee Region

The knee is a common site for injury and inflammation in racehorses, likely due to weightbearing forces causing soft tissue strain. ^[1] Racehorses are also susceptible to fractures within the knee joint due to these forces. ^[1]

8. Synovitis

Synovitis, inflammation of the joint tissues, is a common cause of lameness in young racehorses. ^[1] Horses that have a “back at the knee” conformation have the highest risk, as this conformation results in hyperextension of the knee joint during racing. ^[1]

Treatment involves: ^[1]

• Icing the limb
• Anti-inflammatory medications
• Joint injections 

Many horses recover fully and go on to have successful racing careers. ^[1]

9. Chip Fractures

Chip fractures, small fragments of bone breaking off and floating in the joint, are very common in racehorses. ^[1] These fractures occur due to repetitive strain on the bone resulting in changes in bone shape, ultimately resulting in a small fracture. ^[1]

Treatment typically involves arthroscopy, surgical removal of the fragment using a camera inserted into the joint space. ^[1]

Most horses have a good prognosis after “chip” removal, however some require multiple surgeries as new chips develop during their racing career. ^[1] Left untreated, the chips can migrate around the joint causing damage to other structures, resulting in arthritis. ^[1]

Hock Region

The hock is one of the most important structures involved in equine movement, as it provides the propulsion and strength necessary to move the horse forward. ^[1] The hocks are a common source of lameness in racehorses due to repetitive use during galloping. ^[1]

10. Distal Hock Joint Pain

Distal hock joint pain, or distal tarsitis, refers to inflammation of the lowest hock joints on the horse’s limb. Left unmanaged, distal tarsitis rapidly develops into arthritis, which can impact the horse’s long-term soundness. ^[1]

Treatment for distal tarsitis involves joint injections using anti-inflammatory medications. ^[1] These medications delay the onset of arthritis and make the horse more comfortable, allowing their racing career to continue. ^[1]

Most horses respond rapidly to treatment, however their lameness may recur in the future as the inflammation returns or progresses towards arthritis. ^[1]

Stifle Region

The stifle is a large, complex joint involved in transferring the power of the horse’s hindquarter muscles to the lower limb. Tibial stress fractures are a common stifle injury in racehorses. Stifle pain and arthritis is also relatively common.

11. Tibial Stress Fractures

Tibial stress fractures are the most common cause of sudden hindlimb lameness in racehorses. ^[1] One study on three farms in the United Kingdom showed that tibial fractures accounted for 20.7% of musculoskeletal injuries in this racehorse population. ^[7]

These fractures occur due to the repetitive stresses on the tibia during racing and training. ^[1] Most horses develop these fractures after a hard workout or after breaking from the gate during a race or training. ^[1]

Treatment for tibial stress fractures involves 90 – 120 days of rest, allowing the fracture to repair itself. ^[1] These fractures typically heal rapidly due to the large blood supply in the area. ^[1] Many horses successfully return to racing if given adequate time to heal. ^[1]

Pelvis Region

The pelvis receives much of the concussive and mechanical forces experienced by the hindlimbs, putting it at risk of injury during high-speed movement. Due to these forces, racehorses are at risk of developing pelvic fractures.

12. Pelvic Fractures

Pelvic fractures are thought to be uncommon in racehorses, however they are likely underestimated or misdiagnosed. ^[1] One study showed that pelvic fractures accounted for 15.5% of fractures in racehorses. ^[8]

The most common pelvic fractures are those involving the ilium, the sides of the pelvis between the point of the hip and the point of the buttock. ^[1]

Pelvic fractures likely develop from repeated stress on the bone during racing and training. ^[1] Ultimately, weakening of the bone produces a fracture, which may result in a catastrophic breakdown during racing. ^[1]

Treatment for pelvic fractures involves long periods of rest to allow the bone to heal on its own. ^[1] Most horses can make a full recovery, unless there is displacement of the bone fragment that prevents it from healing back in place. ^[1]

Preventing Injuries in Racehorse

Racehorses experience immense mechanical forces when racing, making them highly susceptible to sports-related injuries. Horse owners and trainers must focus on the health and wellness of their horses to ensure optimum performance and to prevent career-ending injuries.

Working with qualified professionals such as veterinarians, farriers, sports medicine specialists, exercise physiologists, and nutritionists is an important component of robust racehorse management. Each horse requires its own management program to ensure its specific needs are met.

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