HISA emphasizes risk factors for hindlimb fractures

The Horseracing Integrity and Safety Authority announced the publication of new equine health advice on February 26, identifying the main risk factors associated with fatal proximal hindlimb fractures in Thoroughbreds. The advice, which is based on data from the HISA portal, provides practical guidance for trainers and veterinarians on how to help prevent these catastrophic injuries.

In 2024 and 2025, regulatory veterinarians at indoor race tracks reported 28 fatal breakdowns involving tibial (12) and pelvic bone fractures (16). Most (75%) fractures occurred during training; 25% occurred while racing.

Approximately 40% of horses with fatal proximal hindlimb fractures reported to HISA had recorded 10 or fewer rapid furlongs within the 60 days prior to fracture occurrence.

Fatal tibial fractures

Approximately 40% of horses with fatal tibial fractures had zero recorded high-velocity stades over their lifetime; 50% had 10 or fewer rapid furlongs recorded in the 60 days prior to fracture.

Four of these horses (approximately 15%) were listed as unsound by veterinarians at least once in the past year, underscoring the need for careful veterinary evaluation once these horses are flagged by supervising veterinarians. Two others were older, unraced horses: one was unraced at 4 years old; one had not raced at 5 years old. Both suffered fatal tibial fractures.

Fatal pelvic bone fractures

Approximately 80% of fatal pelvic fractures occurred in fillies and mares, while fatal tibial fractures occurred more evenly in both sexes.

These data indicate that a lack of high-speed training, such as in horses just beginning training or returning from prolonged rest, may pose a significant risk for fatal proximal hindlimb fractures, as it does for forelimb proximal fractures.

This is the third health advice for horses that HISA has issued, after advice on proximal foreleg fractures and exercise-related sudden death. Sharing these insights from the HISA portal supports better informed care, promoting best practices and reducing the risk of equine injuries and deaths.

“It is important that HISA uses the data we collect to gain insights and share lessons learned with the industry,” says Dr. Jennifer Durenberger, HISA director of policy and sector initiatives. “This advisory, like the proximal forelimb fracture advisory, aligns with HISA’s commitment to data-driven safety and education among industry stakeholders.”

Read the full advice distributed to trainers and vets.

This press release has been edited for content and style by BloodHorse Staff.