SARATOGA SPRINGS, N.Y. – Frank Stronach, the billionaire owner-breeder and racetrack owner, has sent a letter to racetracks calling for collective action to ban the race-day use of furosemide, the diuretic known as Lasix that is widely used in North America to treat bleeding in the lungs. The letter said that racetrack operators “are the only ones who can make a change happen, but only if we work together. I am asking that as stakeholders with shared interests, we work on a plan to phase in a ban on all [race-day] medication at our tracks.” Stronach, who owns Santa Anita Park, Gulfstream Park, Golden Gate Fields, Laurel Park, Pimlico, and Portland Meadows through his privately held Stronach Group, called for all those who supported the idea to meet in Saratoga Springs on either Aug. 12 or Aug. 14. Several racetrack operators this week confirmed that they had received the letter but declined to comment on it. Late on Wednesday, Churchill Downs Inc., which owns Churchill, Arlington, and Fair Grounds and recently reached an agreement to lease Calder Race Course’s racing operations to Stronach, confirmed it received the letter, and Chief Operating Officer William Carstanjen issued a response expressing a willingness to meet with Stronach on one of the dates. Stronach had not yet responded to Carstanjen by Wednesday afternoon, a Churchill official said. “This is an extremely important issue to us and we look forward to sitting down to discuss this topic,” Carstanjen responded, according to the official. The Stronach letter was sent shortly after a group of 25 trainers signed a statement calling for a gradual phase-out of Lasix. Many of those trainers are based in New York and work for owners who have previously called for a ban on the race-day use of the drug, which is legal to administer in every U.S. racing jurisdiction on race day, usually up to four hours prior to a race. Stronach’s letter indicated that he would support putting in place so-called “house rules” that would prohibit the administration of the drug on race day. House rules are usually enforced as a condition of entry, but they are rarely used to implement policies that are not in place at other tracks because of concerns that trainers will avoid tracks with restrictive rules. “We as track operators must do everything we can to eliminate race-day medications,” Stronach said. “The integrity of our sport and the safety of our athletes, both human and equine, should and must always be of paramount concern. I hope you join me in planning the implementation and promoting the elimination of all race-day medications.” Tim Ritvo, the president of Gulfstream and a former trainer, acknowledged that the call for racetracks to band together to ban the race-day use of Lasix needed a critical mass to avoid dividing the industry. “We’re very conscious that doing it alone would be virtually impossible,” Ritvo said. “Everyone has to come together. If there’s enough industry push, then it can happen.” The Stronach letter and the trainers’ letter have reinvigorated the debate over race-day use of Lasix within a week of the Round Table Conference on Matters Pertaining to Racing, an annual conference put on by one of the most aggressive supporters of a ban on race-day use of the drug, The Jockey Club. On the grounds of the Fasig-Tipton sale Monday and Tuesday, discussion of the drug was nearly as common among trainers in attendance as discussion of the yearlings in the auction ring. Just 12 months ago, faced with the reality that no state racing commission had approved rules restricting the race-day use of Lasix, The Jockey Club and other supporters backed away from their hard line on the issue in order to ease the way for the approval of new uniform rules that include regulations restricting the administration of the drug on race day to state or association veterinarians at a strict dosage. Under the informal truce, the two sides agreed to disagree on Lasix while the uniform rules were put in place. Consensus on the uniform rules was won after years of negotiation between racing’s notoriously disagreeable factions, including trainers, owners, breeders, and racetrack operators. Now, according to several racing officials, the resurrection of the Lasix issue is threatening to break that consensus, at a time when a dozen states are putting in place the rules and other states are attempting to build support for the adoption of the regulatons. The racing officials, who said they were neutral on the issue of race-day Lasix use, did not want to be quoted by name. But on Wednesday night, a consortium of officials from horsemen’s groups associated with the Thoroughbred Horsemen’s Association released a letter that was highly critical of the effort to resurrect the Lasix issue, stating that it was “designed to revive a divisive issue that the industry has already debated at great length and settled.” “It will polarize the industry, cripple the implementation of the uniform medication and drug-testing program, and put the industry at war with itself once again,” the letter stated. The letter was signed by Alan Foreman, chairman of the THA, along with the president of the THA chapters in Illinois, Pennsylvania, New Jersey, Delaware, New York, and Maryland. All of those states have adopted the uniform rules or are in the process of adopting the rules. The letter went on to state that the THA chapters would “continue to strongly and vigorously advocate on [horsemen’s] behalf to oppose any change in current policy and practice, absent scientific evidence to the contrary or breakthroughs that allow for the horse to otherwise be protected.” Echoing many comments made by supporters of a race-day ban, Stronach said in his letter that use of Lasix “has facilitated in creating the weakest collection of horses we have ever seen and is becoming a public-relations problem for our sport.” Supporters contend that both new fans and existing fans are turned off by the race-day use of any drug, even if highly regulated, and breeders maintain that Lasix use in North America is depressing demand for the continent’s bloodstock among foreign buyers. Opponents of a ban, which include nearly every local horsemen’s organization in the United States, have cited scientific studies that have indicated that race-day Lasix use mitigates both the frequency and severity of bleeding in the lungs, a common affliction in racehorses. Approximately 95 percent of all horses in North America are administered the drug on race day, even though studies have shown that only a small percentage of horses bleed severely during exercise.