Efficacy of furosemide in the treatment of exercise-induced pulmonary hemorrhage in Thoroughbred racehorses

Abstract

SUMMARY The repeatability of endoscopic observations of exercise-induced pulmonary hemorrhage ( eiph ) and the efficacy of furosemide as a prophylactic treatment of horses with eiph were studied in Thoroughbred race horses after consecutive breezes (at or near maximum speed, approx 16 m/s). Of 56 horses examined ≥ 2 times, 21 (38%) had identical eiph scores, whereas 26 (46%) and 9 (16%) had scores that differed by ≥ 1 grade. In 56 nontreated horses, there was good agreement between 2 consecutive observations ( K = 0.59, Z = 4.54, P < 0.001). Similar comparisons after placebo (saline solution) treatment of 21 horses yielded fair to good agreement, whereas poorer agreement was seen after furosemide treatment of 23 horses. Comparison of average and maximum eiph scores of 44 horses with a minimum of 4 observations (2 nontreated, 1 saline-treated, and 1 furosemide-treated) indicated that although furosemide did not stop eiph , it did reduce the eiph score in 28 (64%) horses.