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Like people, some horses are born athletes, whose genetic inheritances give them distinct advantages in the gym or on the racetrack. New equipment at OVC will help identify these equine athletes at a young age so that they can receive the appropriate training.

“It’s extremely expensive to raise and train a racehorse, so this can help owners to decide if they want to make that investment,” says Dr. Laurent Viel, Clinical Studies, a specialist in large animal internal medicine. “Using data from VO2 max, we can say that this horse does or doesn’t have the framework to be a great racehorse.”

The new equipment works by identifying a horse’s peak oxygen uptake during exercise. This value, called the “VO2 max”, is a measure of aerobic capacity and athletic potential. The equipment includes a mask worn by the horse, allowing clinicians to track consumption of oxygen and production of carbon dioxide as the horse runs on a treadmill.

In addition to helping identify gifted racehorses at a young age, the equipment can also be used to evaluate reasons for under-performance in more seasoned animals.

“Clinically, a horse might present with inadequate performance, and this could be used to investigate why the horse’s performance is below par,” says Dr. Ray Geor, Biomedical Sciences. “Basically, better performing horses have higher aerobic capacity (VO2 max), and this is a way of measuring that.”

The new VO2 max system has replaced older equipment that was in use at OVC since the early 1990s. It boasts quicker warm-up and calibration procedures, the ability to gather a greater quantity of data and a slick computerized interface.

The purchase was made possible through a generous donation from Mrs. Helen E. Gardiner, wife of the late George R. Gardiner and owner of Gardiner Farms, a breeding and training facility for thoroughbred racehorses in Caledon. The gift was made through the George and Helen Gardiner Foundation.

Viel says that although VO2 max systems are in widespread use as research tools, using the system in a clinical setting for performance evaluation testing is not common.
“We’ve used this as a research tool for over 20 years and have collected a lot of data,” he says. “We’re now trying to push the threshold by making the equipment useful in a clinical sense.”

The VO2 max equipment is currently only used occasionally on clinical patients, but Viel hopes that it may eventually be used almost every day. In turn, using the VO2 max equipment in clinical cases will allow Viel and other researchers to amass new data that could provide even more information about the relationship between aerobic capacity and athletic performance.

The strength of VO2 measurements is that they are non-invasive and allow researchers to collect data about a horse’s oxygen consumption while running.

“The equipment has wide applications as a tool that can help in diagnoses and research,” says Dr. Henry Staempfli, Clinical Studies, who is using the equipment both in research and in clinical cases at the Veterinary Teaching Hospital.

For example, VO2 max data can be combined with the results of muscle biopsies, allowing clinicians to assess oxygen intake and compare it to muscle composition to find out how efficiently the horse’s body distributes its oxygen supply. Analysis of VO2 max data can also help to diagnose problems of the upper airways that are only detectable while the respiratory system is stressed, due to exercise, for example. Paralysis of the vocal cords is one such ailment - horses with this affliction will have lower oxygen intakes than other horses.

But the applications of VO2 max extend even further. For example, Geor recently completed a study examining how changes to a horse’s diet may affect its metabolism. Horses were fed a higher-fat diet and then their aerobic capacity was measured and compared to their performance before the diet changes were introduced.

Viel has used VO2 max measurements in research to investigate the effects of a bronchodilator - a drug that expands the lungs, used to treat asthma in humans - allowing horses with asthma to breathe easier and perhaps perform better.

Staempfli is also using VO2 max measurements in research. One of his research projects involves assessing the influence of electrolytes - electrically-charged particles that aid in metabolic functioning - on performance and physiology of racehorses. Human athletes sometimes drink electrolyte-rich sports drinks during exercise, to boost their performance or endurance. Staempfli used VO2 max data, along with blood samples, to examine the effects of different electrolytes on the lungs during high intensity exercise.

- Karen Gallant