Horse racing does hurt horses, though the degree varies widely depending on the individual animal, how it’s trained, what surface it runs on, and how well it’s managed. Racehorses face a range of physical harms, from stress fractures and lung bleeding to stomach ulcers that affect nearly every horse in active training. The U.S. racing fatality rate dropped to 0.90 per 1,000 starts in 2024, a historic low, but that still means roughly one horse dies for every 1,111 races run.
Musculoskeletal Injuries Are the Biggest Risk
The most visible way racing hurts horses is through bone, tendon, and ligament injuries. In a study of New Zealand racetracks from 2005 to 2011, 77% of all veterinary events during races were musculoskeletal injuries. Of those, 67% were fractures. The remaining cases split between tendon or ligament injuries, lameness, and other soft tissue damage.
Fractures are especially dangerous. In that same dataset, 81% of fractures were fatal or required euthanasia. The overall rate of musculoskeletal injury on race day was 0.72 per 1,000 starts, and the fatality rate from those injuries was 0.41 per 1,000 starts. Longer races carried higher risk than shorter ones, and track condition mattered: softer, slower tracks produced fewer injuries than firm ones.
In the United States, the picture has improved over time but remains serious. When The Jockey Club began tracking fatalities in 2009, the rate was 2.00 per 1,000 starts. By 2024, under the Horseracing Integrity and Safety Authority (HISA), that number fell to 0.90, a 55% decrease over 15 years. That progress reflects real changes in track safety standards, veterinary screening, and medication rules, but it still translates to dozens of horse deaths per year across American racetracks.
Most Racehorses Bleed Into Their Lungs
A condition called exercise-induced pulmonary hemorrhage affects the vast majority of racehorses. When horses gallop at full speed, the extreme cardiovascular pressure can rupture tiny blood vessels in the lungs, causing bleeding into the airways. A study of two-year-old Thoroughbreds found that 74% tested positive for lung bleeding at least once. Severity is graded on a 0 to 4 scale, with higher grades indicating more blood in the airways.
To manage this, the U.S. racing industry has long permitted a diuretic drug (commonly called Lasix) before races. The drug reduces blood volume and fluid pressure, which can lessen bleeding. But its use is controversial. Studies have shown that horses given the drug post faster race times, and it’s unclear whether that improvement comes from reduced bleeding or from other effects like weight loss through fluid loss. The drug also acts as a diuretic, which can make it harder for labs to detect other substances in a horse’s system. Most racing jurisdictions outside North America have banned its use entirely.
Stomach Ulcers Affect Nearly Every Horse in Training
Gastric ulcers are so common in racehorses that they’re considered almost unavoidable during active training. Among Thoroughbreds not in training, ulcer rates in the upper stomach lining range from 37% to 52%. Once those same horses enter race training, prevalence climbs as high as 100%.
Two things drive this. First, intense exercise increases abdominal pressure and stomach contractions, which splashes acid onto the upper stomach lining, a surface that lacks the protective mucus coating of the lower stomach. Second, the typical racehorse diet works against them. Racehorses eat large amounts of grain and relatively little hay compared to horses living on pasture. Chewing hay produces saliva that buffers stomach acid, and the fiber itself forms a protective mat in the stomach. A grain-heavy, low-fiber diet removes both of those defenses.
Ulcers in the lower, glandular part of the stomach are also common, reported in 25% to 65% of Thoroughbred racehorses. These appear to be driven more by the physical stress of training itself. More training days per week correlates with higher rates, possibly because intense exercise disrupts normal blood flow to the stomach lining.
Track Surfaces Change the Level of Risk
Not all racing surfaces are equally hard on horses. Research consistently shows that high-speed exercise on dirt and sand tracks carries a higher risk of catastrophic injury compared to turf (grass). Track condition matters too. In New Zealand data, “dead” and “slow” (softer, wetter) tracks produced significantly fewer musculoskeletal injuries than firmer “good” tracks.
This is one reason many tracks have experimented with synthetic surfaces, though results have been mixed and adoption varies by region. The takeaway is that the surface a horse runs on meaningfully affects whether it gets hurt, and many horses in North America still race primarily on dirt.
Starting Young: Harmful or Protective?
Many people assume that racing two-year-old horses, before their skeletons are fully mature, must cause extra damage. The research tells a more complicated story. Epidemiological reviews have found that two-year-olds are not at greater risk of injury than older horses. In fact, horses older than four face higher injury rates than younger ones. Horses that begin race training at two tend to have longer careers and higher lifetime earnings.
The reason appears to be bone adaptation. A horse’s skeleton is most responsive to physical stress before age two. Moderate, dynamic exercise during this window, such as short sprints or pasture turnout, stimulates the bones to become denser and stronger. This conditioning carries into adulthood and may reduce fracture risk later. Studies in other species support this: animals exercised during adolescence maintain greater bone strength into maturity compared to those that were sedentary.
That said, the type of exercise matters enormously. Short, high-speed work over moderate distances appears protective, while single bouts of long-distance galloping increase injury risk. Young horses in early training also develop a painful condition called “bucked shins” (stress reactions in the front cannon bones) more often than older horses, though this typically resolves and may be part of the bone-strengthening process. The research does caution against corticosteroid use in young horses, as these drugs can interfere with the natural bone remodeling that makes early training beneficial.
Life After Racing
The effects of racing don’t end when a horse retires. Osteoarthritis is the most common long-term consequence. Roughly 60% of all equine lameness cases are linked to osteoarthritis, and the condition is a leading cause of early retirement from athletic careers. Joint cartilage damaged by repetitive high-speed impact doesn’t regenerate well, so many retired racehorses live with chronic joint pain and stiffness for the rest of their lives.
The quality of a retired racehorse’s life depends heavily on what happens after the track. Horses that receive appropriate veterinary care, joint management, and a gradual transition to lighter work can live comfortably for years. But not all retired racehorses receive that level of care, and the industry’s aftercare infrastructure, while growing, still doesn’t account for every horse that leaves racing.
What’s Changed and What Hasn’t
The creation of HISA in the United States brought the first uniform federal safety standards to a sport previously regulated state by state. The authority oversees racetrack safety rules, anti-doping protocols, and a prohibited substances list that limits what medications horses can receive near race day. The 55% drop in fatality rates since 2009 suggests these structural changes, along with better veterinary screening and track maintenance, are making a measurable difference.
But the fundamental physics of the sport haven’t changed. A 1,000-pound animal running at 40 miles per hour places enormous stress on legs that are, relative to body size, remarkably thin. Lung bleeding remains near-universal. Stomach ulcers remain near-universal. And the economic pressures of racing still push some trainers to run horses more often, on harder surfaces, and through minor injuries that a non-racing horse would be rested through. Racing is safer than it was a decade ago, but the sport carries inherent physical costs that no regulation fully eliminates.