Objective—To determine whether exercise-induced
pulmonary hemorrhage (EIPH) was associated with racing
performance in Thoroughbred horses not medicated
with furosemide and not using nasal dilator strips.
Design—Observational cross-sectional study.
Animals—744 two- to 10-year-old Thoroughbred horses
racing in Melbourne, Australia.
Procedure—Horses were enrolled prior to racing, and
a tracheobronchoscopic examination was performed
after 1 race. Examinations were recorded on videotape,
and presence and severity (grade 0 to 4) of EIPH
were subsequently determined by 3 observers blinded
to the horses' identity. Race records were
abstracted for each horse examined.
Results—Overall, 52.1% of horses eligible for participation
in the study were examined, and horses that were
examined did not differ from horses that were not examined
in regard to age, sex distribution, or proportion of
horses that won or finished in the first 3 positions.
Horses with EIPH grades ≤ 1 were 4.0 times as likely to
win, 1.8 times as likely to finish in the first 3 positions,
and 3.03 times as likely to be in the 90th percentile or
higher for race earnings as were horses with grades ≥ 2.
Horses with EIPH grades ≥ 1 finished significantly farther
behind the winner than did horses without EIPH.
However, odds that horses with grade 1 EIPH would win
or finish in the first 3 positions were not significantly different
from odds for horses without EIPH.
Conclusions and Clinical Relevance—Results suggest
that EIPH is associated with impaired performance
in Thoroughbred racehorses not medicated with
furosemide and not using nasal dilator strips. ( J Am Vet
Med Assoc 2005;227:768–774)