Researchers noted that horses with Grade 4 EIPH (more severe bleeding) were significantly more likely to finish in a lower placing and cross the finish line more lengths behind the winner compared to horses without EIPH, Lester said. | Photo: iStock

A study of nearly 1,600 Thoroughbreds racing in Australia between from 2012 through 2015 showed no significant differences in racing results between horses with Grades 1, 2, or 3 EIPH (mild to moderate bleeding) and unaffected horses, said Guy Lester, BVMS, PhD, Dipl. ACVIM, of the Murdoch University College of Veterinary Medicine in the School of Veterinary and Life Sciences, in Western Australia. The study horses had not been treated with furosemide (commonly called Lasix or Salix), a drug used to reduce EIPH severity, before racing.

However, the researchers noted that horses with Grade 4 EIPH (more severe bleeding) were significantly more likely to finish in a lower placing and cross the finish line more lengths behind the winner compared to horses without EIPH, Lester said. They also tended to be less likely to place in the first three positions or collect race earnings. And if they did collect earnings, these were relatively lower per start. Another interesting finding, he added, was that they tended to slow down in the final stretch of the race.

“Bad bleeders (in our study) tended to be faster than other horses in the early to middle stages of the race, but then slower in the last 600 meters,” Lester said