Research could help combat illegal use of banned drug
BY ANDREW VOWLES
Ontario's horse-racing industry may gain a new tool to help combat illegal doping of horses through research at the Ontario Veterinary College involving a hormone recently banned by racing regulators.
Prof. Dorothee Bienzle of the Department of Pathobiology and DVM student Carolyn Cooper studied the workings of erythropoietin (EPO) in horses at OVC. This naturally occurring hormone stimulates the body to make more red blood cells, increasing the horse's oxygen-grabbing capability and improving its performance on the track.
Bienzle says anecdotal reports point to increased use of human EPO in race horses during the past decade, a period that has seen race purses grow as well.
“There's a lot more money to be had than there was 10 years ago, so the stakes are higher,” she says.
Regulators in the province's horse-racing industry have received “lots of anecdotal evidence” about EPO's use, says Bruce Duncan, supervisor of standardbred commission veterinarians with the Ontario Racing Commission (ORC). But officials know little about the extent of EPO doping, how the substance is being obtained and administered and by whom, he says.
Since the ORC banned the substance two years ago, about 10 cases of the hormone's use in Ontario race horses have been reported. Last fall, the ORC adopted a test based on detecting antibodies produced in horses given human EPO. That test was developed at Cornell University by George Maylin, a 1965 graduate of OVC.
In her study this year, Bienzle induced anemia in six horses, allowed them to recover, then treated the horses with human EPO to see whether she could distinguish changes in the blood caused by anemia from those caused by the drug. “Under these conditions, we can distinguish EPO treatment,” she says.
Bienzle believes her project holds promise for a more accurate test for the hormone, although her test would have to be validated in field conditions. She plans to share the results with the ORC, but has yet to complete data analysis and publish the results of the study.
Cooper, a third-year student, was responsible for much of the work on the project, including co-ordinating the transport of horses to OVC for treatments, ordering drugs, collecting blood and bone marrow samples, and entering and analyzing data. Funding for her summer work in Bienzle's lab came from the Natural Sciences and Engineering Research Council.
Cooper says few studies have looked at EPO's effects on horses. “Not only does it help to understand how EPO works as a performance-enhancing drug, but it can also be valuable to those who regularly bleed horses as blood donors.”
EPO, which is secreted naturally by the kidneys, is used therapeutically in people with chronic renal failure, particularly patients on dialysis awaiting transplants. Used improperly to boost red blood cell counts, it may cause “sludging” of the blood and, ultimately, strokes in horses and humans.
Josepha DeLay, a mammalian pathologist with the Animal Health Laboratory at U of G, says current post-mortem tests screen for illicit drugs such as painkillers but not for small amounts of naturally occurring proteins such as EPO. She believes Bienzle's work will help determine the effects of using EPO in race horses and control its use. “As long as a test is available, people will be more careful,” DeLay says.
