By Jackie Bellamy-Zions

Exercise-Induced Pulmonary Hemorrhage (EIPH) is estimated to affect between 44 – 85 percent of Thoroughbreds and up to 87 percent of Standardbreds worldwide. There is concern in racing circles that EIPH can shorten a racehorse’s career and in rare worst-case scenarios, cause sudden death from massive hemorrhage. Dr. Janet Beeler-Marfisi (Ontario Veterinary College, Department of Pathobiology) and her collaborators plan to use data from air quality monitoring stations and weather stations near Woodbine and Woodbine Mohawk Park racetracks in Ontario, cross referenced with endoscopic exams, to determine if there are patterns between EIPH and horses exercising in areas of increased air pollution or in cooler temperatures.

Collaborator Dr. Alison Moore first approached Beeler about the project, based on listening to industry concern from astute racetrack veterinarians who felt there could be an association between environmental conditions and the occurrence of EIPH. “It’s currently on people’s minds”, says Beeler. “This research is born out of the desire to provide optimal health for equine athletes and will involve trainers, owners, and veterinarians working together to find answers to the question of environmental influence.”

Studies in horses are lacking when it comes to linking pulmonary hemorrhage to ambient air pollution (smog) but a relationship has been demonstrated between EIPH and cooler temperatures. Other unrelated studies have drawn a link between hazardous ozone conditions and slower race times. Airway inflammation has also been associated with exposure to air pollution.

Beeler expects that smog and racing during cool or cold months will have the highest likelihood of a statistically significant association with EIPH and decreased racing performance, basing this hypothesis on literature from endoscopically diagnosed EIPH in Ontario Thoroughbreds and Standardbreds.

With over 9,000 horses in the two track locations scoped per year, the two-year study will be drawing data from samples from track veterinarians when the horse owner has agreed to share the information. Owner and horse information will remain anonymous in the research paper. The veterinarians will be working from a standardized form to record endoscopic exam results.

Just as humans can modify their exercise based on a quick glance at weather reports, if the findings of this study confirm links to EIPH and smog in horses, trainers and veterinarians can work to lessen the effects on the horse. Some management changes may include altering training times or intensity on days with high smog or colder temperatures or adjusting post times. Ultimately, further research on a link between EIPH and air pollution could reveal more information about the development of EIPH and reduce reliance on medications such as furosemide.

This project is possible due to a grant from Equine Guelph, generously supported by Ontario Racing. It will be important to trainers and veterinarians in the Ontario racing industry; especially to those with racetracks in close proximity to highways and airports.

Reprinted with the kind permission of Equine Guelph.

Photo: Shutterstock/Dennis W Donahue