The Horseracing Integrity and Safety Authority has approved funding for three studies that will examine the use of furosemide, the diuretic that is used to mitigate bleeding in the lungs, in racehorses, part of a mandate contained in its enabling legislation. The three studies were approved by HISA’s Board of Directors following recommendations issued by its Furosemide Advisory Committee. The costs of the three studies will be $773,500, HISA said. HISA’s enabling legislation, which was passed late in 2020, contained a provision requiring the organization to issue recommendations on the use of raceday furosemide, which is more commonly known as Lasix, within three years of the launch of HISA’s drug-enforcement operations. Those operations started in May of last year. Although most racing jurisdictions ban the raceday use of the drug for 2-year-olds and the drug is not allowed on raceday in graded stakes races, the vast majority of horses in the United States run on the drug, which has been shown to reduce the incidence and severity of bleeding in the lungs. The U.S. remains an outlier in allowing for raceday use of furosemide among major racing jurisdictions worldwide. Supporters of raceday use point to the studies showing mitigation of bleeding, while opponents have said that the raceday use creates public-perception problems for the sport. Opponents also contend that the efficacy of the drug is overstated, and that raceday use creates other physical problems for horses. One of the studies, to be led by Amanda Waller, a research scientist at the Center for Clinical and Translational Research of the Nationwide Children’s Hospital, will examine the “effects of raceday furosemide treatment on the health and welfare of Thoroughbreds as well as their long-term racing performance,” according to HISA. The study will assess the relationship, if any, between furosemide use and fatal injuries, and also compare lifetime performance metrics between horses that raced on furosemide as 2-year-olds and those that did not. A second study, which will be led by SallyAnne L. DeNotta, a clinical assistant professor of large animal medicine at the University of Florida College of Veterinary Medicine, will examine the effects of “repeated furosemide administration” on several biological processes, including bone strength and electrolyte depletion. The third study, which will be led by Warwick Bayly, a professor in the Department of Veterinary Clinical Sciences at Washington State University, will examine the impacts of bleeding episodes on horses’ careers and “seek to determine the extent to which severe [exercise-induced pulmonary hemorrhage] impacts the number of subsequent race starts, the periods between them, and, when applicable the time between the diagnosis of severe EIPH and retirement.” The researchers will be required to complete their studies and issue their findings to HISA’s Furosemide Advisory Committee on or before Jan. 31, 2026. The committee is expected to issue recommendations on raceday furosemide use within several months of receiving the findings. :: Want to learn more about handicapping and wagering? Check out DRF's Handicapping 101 and Wagering 101 pages.