Horse racing

Studying equine cardiac health offers unique insights into predicting and preventing dangerous arrhythmias in people. (Photo by Lukas Gojda on Shutterstock)

In A Nutshell

  • Sudden cardiac death in elite athletes, both human and equine, is rare but often devastating, and racehorses share heart anatomy and disease patterns closely resembling humans.
  • Studying equine cardiac health offers unique insights into predicting and preventing dangerous arrhythmias in people, especially those under extreme physical stress.
  • The One Health approach links human, animal, and environmental health, encouraging cross-species research to tackle shared challenges beyond infectious disease.
  • Horses are also valuable models for studying the gut-brain axis and stress-related illnesses, offering lessons for conditions like IBS, anxiety, and depression.

After a routine gallop on the morning of October 31, 2023, the American thoroughbred racehorse Practical Move collapsed and died. A necropsy, the animal equivalent of a human autopsy, suggested sudden cardiac death.

More than a decade earlier, on March 17, 2012, British soccer player Fabrice Muamba collapsed during a televised FA Cup match, 41 minutes into play. His heart had stopped due to sudden cardiac arrest.

For 78 minutes, Muamba was clinically dead. He was revived after 15 defibrillatory shocks and later fitted with an implantable cardioverter-defibrillator – a device that monitors heart rhythms and delivers shocks when dangerous arrhythmias occur.

Muamba’s story captured global attention, as did Christian Eriksen’s collapse during Euro 2020. But for every elite athlete whose sudden cardiac event makes headlines, there are countless others – both human and animal – who collapse without cameras, coverage, or answers.

Horses suffer many of the same heart conditions as humans, including arrhythmias and sudden cardiac arrest. Like elite athletes, they push their cardiovascular systems to the limit. Their extraordinary physiology makes them a unique, underused model for studying how the heart performs – and sometimes fails – under extreme physical strain.

If we’re serious about improving health outcomes across species, we need to rethink the artificial divide between animal and human medicine. That’s where the One Health, One Medicine agenda comes in.

This approach recognizes that human, animal and environmental health are deeply interconnected. It calls for collaboration between doctors, veterinarians, scientists, policymakers and environmental experts to tackle shared challenges — from zoonotic pandemics and antimicrobial resistance to chronic disease.

While it’s often associated with infectious threats such as avian flu or COVID-19, One Health is equally vital in addressing non-communicable diseases (ones that can’t be passed from person to person), which are now the leading cause of death and disability worldwide.

At its core, One Health starts with a simple idea: humans and animals share the same biological systems. Studying one helps us better understand the other. And, when it comes to cardiovascular health, racehorses offer a powerful example of why that matters.

Racehorses racing with jockeys
Racehorses share heart anatomy and disease patterns closely resembling humans. (Geenee_82/Shutterstock)

From Stable To Surgery

As a cardiac electrophysiologist, a specialist in the heart’s electrical activity in both humans and animals, I see cases every year of horses collapsing during or after races, potentially due to undiagnosed cardiac issues. Exercise-associated sudden death is notoriously hard to predict and devastating when it strikes – not only for the horses and their handlers, but for the racing world more broadly.

Alongside my research team, I’m working to identify subtle electrical abnormalities in the equine heart that could act as early warning signs. Our goal is to understand what causes these sudden cardiac events — and ultimately, to predict which horses are most at risk.

And this research could save lives. Not just equine ones.

What we learn from equine hearts could help transform human cardiac medicine — particularly in athletes or others under intense cardiovascular stress. If we can recognize, manage and prevent rhythm disturbances in high-performing horses, we may find new ways to prevent sudden cardiac arrest in people.

Unlike many lab animals, horses share heart anatomy and disease patterns that closely mirror our own. Their ability to shift from resting heart rates as low as 20 beats per minute to over 200 during exertion offers a natural model of extreme cardiac adaptability.

And the benefits of equine research go far beyond the heart.

Studies of horse physiology are also yielding insights into gut health, immune response and metabolism. As prey animals – species that have evolved to survive being hunted – horses are finely attuned to their environment. Their survival has long depended on their ability to detect and react quickly to potential threats, which has resulted in a highly sensitive nervous system.

This heightened reactivity extends to their gastrointestinal tract, making them especially vulnerable to stress-related gut issues. Environmental changes, emotional distress and social disruption can all trigger digestive problems in horses, including colic and gastric ulcers.

Because of this sensitivity, horses have emerged as a surprisingly valuable model for studying the gut-brain axis – the complex communication network between the digestive system and the brain. They also offer insight into how chronic stress and inflammation can affect long-term health, with potential applications not only in veterinary care but also in understanding human conditions such as irritable bowel syndrome, anxiety and depression.

When we invest in equine health, we’re not just helping animals. We’re expanding what’s possible in human medicine, too.

Breaking Down The Silos

Cardiovascular disease, diabetes, even some cancers — these aren’t just human problems. They’re shaped by shared genetic, environmental and behavioral forces that cut across species.

By dismantling the silos between human and animal health, One Health allows us to share knowledge, pool data, and develop cross-species innovations that benefit us all.

Too often, animal health is treated as separate — or even secondary — to human health. That’s a mistake. Our well-being is tightly bound to the health of the animals we care for and the environments we share.

A renewed focus on equine well-being doesn’t just improve outcomes for horses. It sharpens our understanding of physiology, strengthens public health, and helps prevent avoidable deaths — on and off the track.

If we want to reduce the risk of sudden cardiac death in athletes — or anyone pushing their body to its limits — we need to widen the lens.

That means recognizing the value of research in veterinary medicine. It means turning the stethoscope toward the stable. Because when a horse collapses on the track, it’s more than a tragedy. It’s a missed opportunity — to understand, to prevent and to save.

Kamalan Jeevaratnam, Head of School of Veterinary Medicine, Professor in Clinical Physiology, University of Surrey. He receives funding from British Heart Foundation, Horseracing Betting Levy Board, Hong Kong Jockey Club Equine Welfare Research Foundation, Petplan Charitable Trust, Grayson Jockey Club Research Foundation

This article is republished from The Conversation under a Creative Commons license. Read the original article.

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1 Comment

  1. Rafael says:

    Did the horses get MRNA shots before sudden death ?