South African Study on EIPH

An international collaboration of equine researchers launched a study in early July to examine the prevalence and severity of exercise-induced pulmonary hemorrhage (EIPH) in horses in South Africa. The researchers from the University of Pretoria, The Ohio State University (OSU), and the University of Kentucky (UK), also plan to examine the effect of altitude on EIPH in the Thoroughbred racehorse.


Dr. Montague Saulez, Clifford Matjiane, Prof. Alan J. Guthrie, and Dr. Kenneth Hinchcliff perform a tracheoscopy on "Royal Blue."

Exercise-induced pulmonary hemorrhage is well known for its negative effect on high-performance equine athletes, and has been detected in anywhere from 40-70% of Thoroughbreds racing in the United States and elsewhere, depending on the study (affected horses are often called "bleeders"). Definitive diagnosis is by post-exercise (within 90 minutes of racing) endoscopic examination of the upper respiratory tract and detection of blood in the trachea. This condition has severe economic and welfare implications for the racing industry.

Professor Alan J. Guthrie, BVSc, PhD, director of the Equine Research Center (ERC) at Pretoria's Faculty of Veterinary Science at Onderstepoort; Montague Saulez, BVSc, MS, MRCVS, of ERC; Kenneth W. Hinchcliff, BVSc, MS, PhD, Dipl. ACVIM, professor in the Department of Veterinary Clinical Sciences at OSU; and David W. Horohov, PhD, an immunologist at UK's Gluck Equine Research Center, are heading the project.

This study uses similar techniques to a study completed in Australia in 2003 and presented in 2004 by Hinchcliff (, in which he demonstrated that EIPH has a significant negative relationship with race performance of Thoroughbreds. The researchers will also monitor racehorses at sea level and at altitudes above 1,500 meters (roughly 4,500 feet) to determine whether altitude significantly affects the frequency of EIPH. Finally, Horohov's laboratory will assist in determining whether inflammation conditions are present in horses affected by EIPH.

"EIPH is a serious problem for the equine industry and the underlying mechanism remains unclear," said Horohov. "Here we hope to determine whether EIPH is associated with the induction of an inflammatory condition characterized by the production of certain cytokines (substances produced by white blood cells when there is inflammation in the body). This information could lead to new ways to treat or prevent this condition."

This study of more than 800 horses will provide important new information about EIPH that will serve as a reference point for future research on this economically-important disorder. 

About the Author

Stephanie L. Church, Editor-in-Chief

Stephanie L. Church, Editor-in-Chief, received a B.A. in Journalism and Equestrian Studies from Averett College in Danville, Virginia. A Pony Club and 4-H graduate, her background is in eventing, and she is schooling her recently retired Thoroughbred racehorse, Happy, toward a career in that discipline. She also enjoys traveling, photography, cycling, and cooking in her free time.

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