Rossdales’ internal medicine specialist Dr Celia Marr, who is an internationally recognised expert in equine cardiology, is part of a team of researchers carrying out a new trial to find out why some Thoroughbreds collapse and die during exercise.
Manothepeople running at Ascot 22.11.25. Image Abbie Kyte / Focusonracing.com
This is a significant research project conducted in collaboration with the British Horseracing Authority (BHA), the Horse Welfare Board and Racing Foundation, and involving Professor Kamalan Jeevaratnam and his team at the University of Surrey.
Exercise Associated Sudden Death (EASD) in racehorses is very rare, affecting 0.04% of starters – 50% of which are believed to be heart related. But the precise cause is often difficult for pathologists to prove during post-mortem due to the absence of any other clinical signs.
Although recent advances in technology have allowed accurate ECGs to be obtained from galloping horses, until recently the technology has not been there to monitor hearts under race conditions.
The first pilot scheme of 10 horses ran over the summer, with Ted’s Friend becoming the first horse to wear a heart monitor while competing in a race. The pilot involved the use of an Arioneo Equimetre wearable device which goes under the saddle and is attached to the girth.
At Ascot and Windsor last week, the first three horses of the second pilot of 10 horses were fitted with a an Equimetrics saddle pad heart monitor.
Last year, at an International Federation of Horseracing Authorities veterinary conference on EASD in Canada, discussions concluded that it was not really known what was normal for a horse’s heart during a race.
“It’s partly due to not having the technology,” says Dr Marr, “Now you have something similar to a scaled-up Apple Watch which gives us the opportunity to collect ECGs relatively easily and en masse.”
“The first aim is to characterise what is normal. Can we adapt this equipment to work in a racing environment? We’re exclusively collecting heart data, but stride pattern could also be measured. However, compared to the ECG I can carry out on a horse at Rossdales Equine Hospital in Newmarket, we’re still at the stage where it’s like using bathroom scales compared to nuclear scales – it provides useful information but it has its limits.”
She added: “Early next year the aim is to roll this out more widely so we can begin to figure out what normal is. We already know there is a 10% increase in heart rate in a race compared to the gallops at home and that the rhythm is more variable. These small observations are showing we’re on the right track.”
Dr Marr explained that Professor Kamalan Jeevaratnam’s team at the vet school are interested in developing an AI tool to read ECGs. “All the data collected is fed into the project with the goal that a computer reads an ECG. Currently we’re just studying 10 horses and it takes me half an hour per horse to read the ECG so we need a more efficient way of reading it.”
Dr Sally Taylor, the British Horseracing Authority’s Head of Equine Regulation, Safety and Welfare, says: “By investigating the electrical activity of the horse’s heart during racing and training we will be able to better understand why some horses suffer cardiac arrest with the ultimate aim of screening horses to prevent it happening.”
Read more about British racing’s pilot of heart monitors on the racecourse.
Images courtesy of the BHA and Abbie Kyte / Focusonracing.com