Research Project to Examine Effectiveness of Adjunct Bleeder Medications

A study that will research the efficacy of aminocaproic acid and conjugated estrogens as treatments for the prevention of exercise-induced pulmonary hemorrhage (EIPH) in horses has been selected to receive a one-year, $75,000 grant.

The project will be led by Dr. Howard H. Erickson, a professor of physiology at the Kansas State University College of Veterinary Medicine. Funding the study are the American Association of Equine Practitioners (AAEP) Foundation, the Grayson-Jockey Club Research Foundation, and the Racing Medication and Testing Consortium (RMTC).

EIPH is bleeding within the lungs that occurs as a result of the maximal effort of horses during exercise. The unique anatomy of the horse's lungs, combined with its remarkable athletic ability, can result in the rupture of small capillaries and the leakage of blood into the airway.

All horses experience EIPH, with the severity varying between horses. During a racehorse's career, the consequences of repeated bleeding episodes include inflammation and scarring of the lungs and sometimes an early end to a racing career due to mediocre performance or uncontrolled bleeding.

Furosemide is the primary treatment for the disorder, but no treatment has been shown to totally eliminate EIPH. Aminocaproic acid and conjugated estrogens are approved by some racing jurisdictions as adjunct bleeder medications on race day; however, no controlled laboratory studies have been conducted to determine the degree of efficacy or the advisability of use.

Erickson's study will attempt to determine if these treatments are effective in reducing the occurrence of EIPH and whether they have any direct effect on performance.

EIPH and the use of adjunct bleeder medications are of great concern to the racing industry for the appropriate care of the racehorse. In its determination of appropriate race-day medications, the Racing Medication and Testing Consortium has cited adjunct bleeder medications for potential use, if efficacy can be proven.

The AAEP's annual Racing Forum identified the use of adjunct bleeder medications as a priority need for investigation, thus initiating the AAEP Foundation's solicitation of research proposals on the subject.

"This grant is an excellent example of the equine industry cooperating to improve the health and welfare of the horse," said AAEP past president Dr. Larry R. Bramlage, DVM, MS, who coordinated the call for proposals. "The project was recruited by the AAEP Foundation through a competitive granting process, and the partnership in funding by the Grayson-Jockey Club Research Foundation and the Racing Medication and Testing Consortium is making this investigation possible."

The three organizations are each contributing $25,000 to the study. The progress of the grant will be monitored by the Grayson-Jockey Club Research Foundation using its monitoring and completion assessment system.

Erickson's study will run from March 1, 2006 through Feb. 28, 2007.