More Questions Than Answers
Dr. Celia Marr on Sudden Death, Science, and Why Vets Must Keep Asking
At Naas Racecourse, during one of the most anticipated CPD events in the veterinary calendar at the minute, the room was packed, 45 vets from across Ireland. And, they were not just there for the racing, not for the refreshments, but for the keynote from one of the world’s foremost voices in Exercise Related Sudden Death: Dr. Celia Marr.
Calm, clear, and direct, she spoke about a subject that remains as complex as it is emotionally charged — sudden death in racehorses.
“I’m fundamentally an equine clinician based in Newmarket,” Celia began. “My main qualification is in internal medicine, but I’ve always been interested in heart disease. So I came today to talk about some work on sudden death — in particular, the risk factors, the pathology, and the challenges in diagnosing the causes.”
For a long time, this has been Celia’s field. But it’s only recently that the public lens has turned toward it — and with intensity.
“Yes, it’s a hot topic now,” she said. “There’s more and more of a spotlight on animal welfare in general terms — the use of horses in sport and so forth. But I don’t think we should get defensive about that.”
Her tone was steady and grounded across her talk. You could hear a pin drop at times. “Racehorses are incredibly well cared for. They’re dealt with by people who know them and love them and do their absolute best for them. That doesn’t mean we can’t improve — but we should be striving to improve outcomes, not apologising for the work we already do.”
Much of her presentation revolved around the gap between visible symptoms and root causes — and the limits of what post-mortems can tell us.
“One of the common things we find in horses that die suddenly is haemorrhage in the lungs or heart,” Celia explained. “But the post-mortem shows the end result — it doesn’t show where it started.”
In many cases, she noted, there are multiple routes to the same outcome. And without live data, it’s nearly impossible to pinpoint the origin. “Did it start in the heart and affect the lungs, or vice versa? We don’t know.”
It was this point — the uncertainty, the open space — that resonated with many in the room. One vet, Mairead O’Grady, summarised it after the talk: “Three people can look at the same data and come to different conclusions — and none of them are necessarily wrong.”
Celia agreed. “That’s exactly it. Particularly with these sudden deaths, at least a third of horses have no obvious explanation at post-mortem. In many others, heart or pulmonary disease is suspected — but the exact pathway isn’t clear.”
What drew extra attention was her repeated reference to a different sport entirely: football.
“Everyone remembers Christian Eriksen,” she said. “Young, healthy athletes — prone to sudden cardiac arrest. Some of the causes in footballers don’t apply to horses, like hypertrophic cardiomyopathy, which horses don’t get. But others — like ion channel disorders — might. These are the molecular gateways in cells that allow electrical activity in the heart. There are parallels.”
She drew the line carefully. “When these events happen in football, the players are surrounded by doctors, trainers, and physios — all trained in CPR, with the best equipment. If you’re going to arrest, do it at a Premier League match. In horses, we don’t have that. But we do believe that some of what happens may be the equine equivalent.”
And that’s why events like this one — hosted by Forte Healthcare, and built around both expertise and open conversation — matter.
“For a topic like this, where there are far more questions than answers, everybody’s input is valuable,” Celia said. “It’s a great opportunity for vets in practice to hear what’s happening in research — and for us to get feedback from the field.”
Just before stepping away to speak with another guest, she added one more thing. “And of course — it’s a fun experience.”
