Exercise induced pulmonary hemorrhaging (EIPH) is bleeding in the lungs caused by bursting capillaries during intense exercise like racing. Around 80% of racehorses experience EIPH. Furosemide (Lasix) is used to prevent fluid buildup in the lungs and reduce EIPH occurrences. However, its effectiveness is debated as it may cause dehydration or mask other drugs while not improving race performance. EIPH also seems to have a hereditary component, so widespread Lasix use could increase genetic selection for EIPH over time.

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EIPH
Exercise Induced Pulmonary Hemorrhaging
Causes of EIPH
Locomotor Respiratory Coupling causes
bursting capillaries
Previous lung damage
Previous EIPH
EIPH is
monitored
by...
Subjective
scoring system
from 1-5
will develop
of US Racehorses
80%
EIPH
EIPH must be prevented to continue racing

2. Furosemide
(Lasix)
Legalized for US
Racetracks in 1995
Also known as Lasix
Used to prevent fluid buildup in lungs
Lasix reduces
fluid by
11-13%11.6 cases
Lasix dropped EIPH
cases from 58 to
**Furosemide is used
to prevent and treat
EIPH**

3. Is Lasix
EFFECTIVE
for EIPH?
No improvement
in track times
Dehydration of fluid
Reduction causes
unfair weight
advantage
Potential Drug
Masking Abilities
More evidence shows
heritability of EIPH
which is covered by
the use of Lasix.. This
can cause selection of
EIPH gene. Increase
need for Lasix.
Hinchcliff, K. et al. 2009. Efficacy of Furosemide for Prevention of Exercise-Induced
Pulmonary Hemorrhage in Thoroughbred Racehorses. JAVMA. Vol. 235: 76-82.