A new study shows that horses treated with a diuretic before racing had less hemorrhaging in their airways and lungs during exercise.
Use of furosemide, which is sold as Lasix and Salix, to treat pulmonary hemorrhaging in racehorses began in the 1970s. The study seemingly fuels the argument that Lasix should be administered to horses on the day of a race. That practice is legal in the United States, but most countries ban the use the drug on race-day because it enhances performance.
The study was conducted by Colorado State University, the University of Melbourne and the University of Pretoria in the Republic of South Africa.
Doctors studied 167 horses in South Africa in 2007. Each horse raced twice, one week apart, in the same field and in races of the same distance. In the blinded study, each horse received furosemide, also known as Lasix, before one race and saline solution before the other race.
Endoscopy was performed within 30-90 minutes after racing to identify the presence of blood in airways.
The research showed that giving furosemide before a race dramatically decreased the incidence and severity of exercise-induced pulmonary hemorrhage, or EIPH. Horses were three to four times more likely to have any evidence of bleeding without furosemide, and were seven to 11 times more likely to have severe bleeding without it.
Although furosemide has been used in the racing industry for several decades, no scientifically sound studies have been conducted to prove or disprove an effect on EIPH.
``The results of this study do not eliminate debate about the use of this medication in racehorses, but it does provide evidence needed to aid making sound policy decisions,'' said Dr. Paul Morley, one of the principal investigators of the study and a veterinarian at Colorado State University.
``This is not earth-shattering, but confirms what we've known clinically for several years,'' said Dan Dreyfuss, the first veterinarian on the scene when Barbaro went down at the 2006 Preakness. ``It's nice that it done under blind conditions, because that's the only objective way of doing the study.''
Dreyfuss said the group's finding ``confirmed smaller studies that were done a number of years ago.''
