Studying Catastrophic Racehorse Breakdowns: Research That Can Save Lives

At the Feb. 2 University of Kentucky (UK) Equine Showcase, Laura Kennedy, DVM, Dipl. ACVP, assistant professor and veterinary pathologist at the UK Veterinary Diagnostic Laboratory, shared what researchers are learning about catastrophic breakdowns in racehorses. She discussed how the Kentucky Horse Racing Necropsy Program began as well as what the group studies and some of its findings.

Kennedy said the Necropsy Program was started in 2009 following two high-profile cases of catastrophic breakdowns: 2006 Kentucky Derby winner Barbaro, who sustained serious injuries in that year’s Preakness Stakes and eventually succumbed to related issues in 2007, and Eight Belles, who broke down and was euthanized on the track after finished second in the 2008 Kentucky Derby. Since its founding, the program has documented injuries and, over time, has expanded its research. From 2009 to 2012, racing fatalities were examined; beginning in 2012, all fatalities (racing, training, and medical) that occurred at sanctioned racetracks in Kentucky were examined.

Just like in human athletes, Kennedy said, horses’ bodies experience repetitive use wear as they train and compete over their lifetime, and more than 85% of catastrophic injuries result from preexisting conditions when it is a musculoskeletal-related fatality.

The wear related to a catastrophic breakdown can be shown as also occurring on the opposing (contralateral) limb. That’s why pathologists examine both limbs at necropsy, to include document the fatal event as well as changes in the contralateral limb. Information from the contralateral limb can provide valuable information regarding the horse’s condition. Examination protocols have become increasingly formalized and standardized, Kennedy said, resulting in the development of a scoring system for pre-existing conditions to provide a quantitative evaluation that is better suited to research aims.

Part of the problem with evaluating wear on the horse’s limbs, program researchers have found, is a disconnect between the horse’s overall fitness and the skeletal structure’s fitness. A horse can become strong and in top form quickly during race training, but the bones take time to build strength against the hard impact of galloping.

“You can get a horse really fit really fast, but there’s no way to rush bone,” Kennedy said.

As mentioned, Necropsy Program researchers complete a standard examination for every horse with catastrophic injuries they assess. The group documents preexisting conditions and examines pathology from all angles to better understand each individual breakdown. That knowledge then contributes to the overall understanding of catastrophic breakdowns in racehorses in general.

With this information, the Kentucky Horse Racing Necropsy Program hopes to make a difference in the number of catastrophic breakdowns that occur. Kennedy said one of the program’s overarching goals is to identify horses with pre-existing conditions that could lead to a fatality and intervene before a catastrophic breakdown occurs. Kennedy also stressed that the hazards of a catastrophic breakdown are not only to the horse, but to jockeys as well, as they can be injured or even killed when an equine racing fatality occurs.

Kennedy concluded her talk by explaining that Kentucky Horse Racing Necropsy Program researchers will be working closely with the UK Equestrian Sports Research Initiative, especially the Equine Sports Science Initiative. Data driven research will be gathered and the outcomes communicated to grooms and trainers in the industry, in hopes that catastrophic breakdowns can continue to be prevented as much as possible.

Maddie Regis, a junior majoring in marketing, is the communications and alumni relations intern for UK Ag Equine Programs.

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