ELMONT, N.Y. &ndash; Stark differences in the use and regulation of the diuretic furosemide between North America and every other major racing jurisdiction were highlighted Monday on the first day of a two-day summit at Belmont Park to discuss the medication, commonly known as Lasix.\r\nThe differences underscored the chasm between North America and the rest of the racing world when it comes to the use of furosemide, which is administered legally on raceday to 90 percent of the horses running at North American racetracks to treat bleeding in the lungs. The United States and Canada are the only major jurisdictions that allow for the raceday use of furosemide. During afternoon panel discussions, representatives from the United Kingdom, Ireland, Hong Kong, and Australia said that furosemide should be banned on raceday.\r\n&ldquo;We&rsquo;re not trying to tell you what to do,&rdquo; Dr. Anthony Stirk, the senior veterinary adviser to the British Horseracing Authority, told the 180 attendees during a panel discussion about how furosemide use is regulated worldwide. &ldquo;That&rsquo;s not the intention. We&rsquo;re trying to tell you what we do and what the consequences are. My worry for American racing is that you&rsquo;ve become isolated.&rdquo;\r\nThe two-day summit was organized by three U.S.-based racing organizations, the National Thoroughbred Racing Association, the Racing Medication and Testing Consortium, and the American Association of Equine Practitioners after a number of influential racing groups &ndash; including the Jockey Club, the Breeders&rsquo; Cup, and the Association of Racing Commissioners International &ndash; began calling earlier this year for furosemide to be banned on raceday. The call has been resisted by horsemen, who maintain that raceday furosemide use is a critical tool in keeping horses healthy and treating a malady that affects a large number of horses.\r\nOne of the most controversial elements of the debate is just how many horses are critically affected by bleeding in the lungs. Most U.S. horsemen maintain that nearly all horses bleed &ndash; citing studies that use endoscopes to examine the upper airway for any traces of blood &ndash; but most international horsemen contend that horses that do not visibly bleed from the nostrils should not be considered bleeders.\r\nIn Hong Kong, for example, where the racing population is tightly regulated and veterinary examinations are required for any horse that runs poorly, an average of 0.5 percent of all horses racing over the past five years have bled from the nostrils, according to Dr. Brian Stewart, head of veterinary regulation for the Hong Kong Jockey Club. Another 0.6 percent had a &ldquo;substantial quantity of blood&rdquo; in their tracheas after a poor performance, Stewart said.\r\nThose horses that bleed from the nostrils or have a significant amount of blood in the trachea are banned for 30 days, according to Stewart. But those horses that show only traces of blood in the upper airway &ndash; where just a few drops of blood can streak across the wet surface to create a vision that can appear far worse than the actual condition &ndash; are sent back to the barn and allowed to race.\r\n&ldquo;We do think blood at the nostrils is a significant welfare issue,&rdquo; Stewart said. &ldquo;What we don&rsquo;t think is a welfare issue is traces of blood in the trachea several hours after the race. We don&rsquo;t think that affects performance.&rdquo;\r\nBy contrast, in the United States, horses can be diagnosed as bleeders &ldquo;with one phone call,&rdquo; said Christophe Clement, a native of France who was an assistant in his home country but who has trained in the United States for two decades.\r\n&ldquo;A lot of the difference [between North American and other foreign jurisdictions] is in how often we look for the problem,&rdquo; said John Kimmel, a U.S. trainer and veterinarian.\r\nU.S.-based trainers &ndash; even those with backgrounds in Europe &ndash; described how they routinely scoped horses after disappointing workouts or bad races in order to qualify for bleeders&rsquo; lists at U.S. racetracks. Under model rules adopted by almost all U.S. racing states, a 250-milligram dose of furosemide is allowed to be administered four hours before a race, after extensive research determined that the dosage and time of administration limited the drug&rsquo;s ability to interfere with post-race drug testing but still remained effective in treating bleeding.\r\nThe first day of the summit was designed to provide a backdrop to a closed-door discussion Tuesday in which participants in the U.S. racing industry will attempt to break a stalemate between supporters and opponents of reform. Organizers of the summit have said that they do not expect any consensus to emerge from the meeting, but that they hope to advance the debate on the issue.