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Bleeding: How It Affects Race-Day Performance in HorsesBy Kentucky Equine Research Staff · February 28, 2017

Exercise-induced pulmonary hemorrhage, known also as EIPH or bleeding, often shoulders the responsibility for subpar performance among racehorses. Researchers at Murdoch University, in Western Australia, set out to determine if EIPH is associated with race-day performance*.

The retrospective study included 1,567 Thoroughbred racehorses and 3,794 observations of these horses between 2012 and 2015. None of the horses were raced on furosemide, as it is not an approved race-day medication in Australia. Horses were examined no earlier than 30 minutes after racing, and were recorded and graded independently by two skilled veterinarians using a 0-4 scale, with 0 denoting no bleeding and 4 signifying considerable bleeding.

EIPH was noted in 55% of all observations. Grade distribution shook out like this: 31.6%, 17.2%, 5.1%, and 1.2% for grades 1-4, respectively. Horses with higher grades of hemorrhage showed the most significant effect on performance. “When compared to horses without hemorrhaging, this group was significantly more likely to have a lower finishing position, less likely to place in the first three positions, less likely to collect race earnings, finish further behind the winner, and were slower over the last 600 meters of the race,” the researchers noted.

Of particular note, the study revealed there were “minimal effects documented” between horses with no bleeding and those with grade 1-2 bleeding. “No association was identified between lifetime earnings, overall race speed, or Betfair starting price for any grade of EIPH compared with grade 0, or with EIPH grade 0-2 compared with EIPH grade 3-4.

In sum, researchers found no link between mild to moderate EIPH and race-day performance in the records of those Thoroughbred racehorses examined retrospectively.

Use of furosemide before fast work or racing to curtail EIPH is a common practice in many racing jurisdictions. Furosemide causes electrolyte loss and imbalance through increased urination. When coupled with electrolyte losses that occur naturally with sweating, total electrolyte depletion can be significant following intense exercise. Without proper electrolyte replenishment, complete physiological recovery may be delayed, setting the stage for longer intervals between races.

Kentucky Equine Research formulated an electrolyte product called Race Recovery specifically for horses treated with furosemide. Race Recovery provides targeted electrolyte supplementation and ensures complete, optimally timed electrolyte replacement. In addition to sodium, chloride, and potassium, Race Recovery includes highly digestible forms of calcium and magnesium, two key minerals.

Learn more about Race Recovery by reading Furosemide (Salix® or Lasix®) Use in Horses: A Nutritional Perspective.

*Crispe, E.J., G.D. Lester, C.J. Secombe, I.D. Robertson, and D.I. Perera. 2016. The association between exercise induced pulmonary haemorrhage and raceday performance in Thoroughbred horses. In: Proc. 38th Bain Fallon Lectures. Equine Veterinarians Australia, p. 14.