Churchill Downs and Keeneland have submitted proposed rule changes to a Kentucky regulatory body seeking a limited phase&#45;out of the raceday use of the anti&#45;bleeding medication Lasix and restrictions on the use of other therapeutic medications, according to officials for the tracks.The submission was divulged at a Thursday meeting of the Kentucky Equine Drug Research Council, an adjunct of the Kentucky Horse Racing Commission, and first reported by the Paulick Report. The proposed rules changes dovetail with an announcement earlier this year from several tracks that they would seek additional restrictions on medication use as part of an effort to counter criticism of the sport from a wide assortment of racing and non&#45;racing organizations.The rule changes would seek a ban on the raceday use of Lasix, a diuretic, for all 2&#45;year&#45;old races beginning next year, and a ban on the raceday use of the medication in all stakes races beginning in 2021, according to Mike Ziegler, the executive director of racing at Churchill Downs and a member of the Equine Drug Research Council. The proposal would also ban the use of any non&#45;steroidal anti&#45;inflammatory drug within 48 hours of a race and limit the administration of any corticosteroid to 14 days prior to a race.Under Kentucky&rsquo;s current rules, Lasix is currently legal to administer on raceday in all races, though the administration is regulated and restricted to state veterinarians. Legal non&#45;steroidal anti&#45;inflammatory drugs and corticosteroids have different withdrawal times based on the specific medication, but several common NSAIDs, such as phenylbutazone, are legal to administer 24 hours outside of a race, while some corticosteroids, which are anti&#45;inflammatory medications, can be administered within seven days of a race.Ziegler said on Friday that the submission is the start of what is expected to be a long, controversial process to change the state&rsquo;s rules. Because the proposal deals with medication rules, Ziegler said he expected that the proposal would first need to be approved by the Equine Drug Research Council and then taken up by the Rules Committee of the racing commission. The rules would then need to be forwarded to the full racing commission for approval.&ldquo;We expect this to have to go through the full process,&rdquo; Ziegler said. &ldquo;All interested parties will have a chance to weigh in.&rdquo;The announcement in April from the tracks and several other major racing organizations came in the wake of strident criticism of the sport due to a spate of racing and training fatalities at Santa Anita Park in Southern California in the first half of the year. While some organizations have been pushing for federal legislation that would revamp the regulation of the sport, Churchill Downs and other groups have been attempting to circumvent that push by working through state racing commissions for the changes they are seeking.The proposed phase&#45;out of raceday Lasix use is the most controversial aspect of the changes, as most horsemen&rsquo;s groups oppose any ban, no matter how limited, on the raceday use of the drug, which has been shown in scientific studies to mitigate the incidence and severity of bleeding in the lungs. However, the raceday use of any drug is considered anathema to many racing and non&#45;racing groups, and it is banned on race day in nearly every other major racing jurisdiction in the world.