The Heart of the Matter 2: Monitoring the Massive Engine of the Equine Athlete
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If you’re squeamish about blood, surgery, or dissection, you might want to skip this video.
In 2011, a British Channel 4 television series called Inside Nature’s Giants dissected a Thoroughbred racehorse for viewers. The fascinating documentary described the racing animal as a massive engine of energy and detailed how the operating system of windpipe, lungs, and heart drive the muscles and skeleton.
A critical point in the documentary is when television host (and veterinarian) Mark Evans pulls the heart out of the dissected cadaver–a racehorse who was the victim of a fatal breakdown injury.
Watch the fullNature’s Giants: Inside the Racehorse documentary here.
Equine researchers are still trying to establish baselines on what is normal heart activity for the athletic horse. Great strides have been made by our friends at the University of Guelph, as described in this video about their research on a Standardbred racehorse during a race:
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Using an on-board heart rate monitor attached to the horse’s harness, Dr Physick-Sheard and his students could stand on the track apron and watch a screen readout of a test horse’s actual heart rate during a race. The horse’s beats per minute rose from 40 while he was in the paddock to 240 as the horse rounded the far turn for the stretch run. Was 240 beats per minute enough?
While it’s great to have the ability to follow a single test horse working at race speed, what can be done to prevent cardiac-related deaths of the hundreds of racehorses that take to the track each day?
In Pennsylvania, veterinarians at a harness track took the initiative a few years ago to begin routine stethoscope examination (called auscultation) of racehorses in the paddock before they race. This great little video news story details their simple response to the tragic death of two racehorses from cardiac problems. They simply came up with a plan and implemented it in order to do their part to possibly prevent more deaths.
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They had no big research fund, they just figured out a way to do what they thought needed to be done, and the racetrack and trainers cooperated.
Similar research was conducted by the US Eventing Association during the cross-country phase of a three-day event. For much more on the USEA’s research, read Have a Heart: US Eventing Cardiovascular Task Force Marches on at Red Hills Horse Trials here on The Jurga Report.
But what about when things aren’t normal? The Tufts University Cummings School of Veterinary Medicine’s Sportsmedicine team created a slide show on a sport horse that exhibited loss of performance attributed to gastric ulcers and a heart rate variation.
The text on the slides may be a bit difficult to follow for non-veterinarians, but the point is clear: that heart rate problems require monitoring to both 1) diagnose the problem in the first place and 2) to monitor the effects of medication and their subsequent dosage or frequency of administration.
Tufts offers an in-depth page to help horse owners understand cardiac arrhythmias in the horse.
Has your horse ever had its heart rate monitored? If this story was about poor performance for a fetlock or hock injury, it would be read by ten times as many people as will read this one. That’s because you can see a horse’s lameness. Your veterinarian can easily, and without too much expense, show you a radiograph that might pinpoint the problem.
But a heart rate irregularity is much more complex to diagnose and the tests may not be available to or affordable for every horse’s owner.
But it’s coming. The strides made in eventing and racing, along with the embedded focus on cardiac health in the entire sport of endurance, are pioneering baby steps for what is to come in the future. You may not be thinking about your horse’s heart rate as a factor in his athletic success yet, but you will…and you’ll be able to keep track of what your horse’s individual cardiac patterns are, and identify any possible problems.
And if you’re a recreational horse owner, you should know that research projects conducted on racing or sport horses are bound to become affordable and available to you and your horse in the near future.
Clinical veterinary medicine will be right behind the researchers with new treatments and medications to assist your horse, but let’s hope they learn about the causes of problems so we can avoid them with identification of heritability factors, proper training and conditioning so that tragedies may, as much as is possible, be avoided before they happen.
Heart of the Matter is a multi-article series published in The Jurga Report in January 2012 as background for readers interested in new developments for cardiac health in horses. The Jurga Report dedicates the series to the memory of the great show jumper and Olympic champion Hickstead, whose tragic death, caused by acute aortic rupture,?occurred on November 6, 2011.
Hopefully Hickstead’s death will ignite more interest in equine cardiac research. Tufts and the University of Guelph are just two of the university veterinary schools that are involved in equine cardiac research.