[Danzig]

found this while trying to find info on lasix in foreign countries:

Long Term Lung Changes in ‘Bleeders’
It is well known that once a horse has a ‘severe’ bleed, it’s
subsequent race performance is likely to be reduced. The upper,
back sections of the lung receive high blood flow during
exercise, and is the area which exhibits evidence of vascular
changes and long term damage following a severe ‘bleeding’
episode. Prof. Frederik Derksen and other leading, well known
researchers at Michigan State and Melbourne University,
investigated the effects of bleeding on lung pathology. It is
currently believed that bleeding (or Exercise-Induced Pulmonary
Haemorrhage (EIPH) results from high internal blood pressures
(hypertension) and stress failure of the walls of the lung airsac
(alveolar) capillary arteries in all-out pacing and galloping
horses. However, the pathological changes that would be
expected in this case, with vessel fibrosis, blockage and small
bypass vessels that form within the bronchial walls, were not as
severe as previously identified. The new Michigan study
identified significant lung vascular changes, including increased
vein hypertension in the lung drainage vessels after a ‘bleeding’
episode. It was also found that both lungs had similar changes,
despite previous findings that the hind lobes of the left lung were
more scarred following a severe ‘bleed’. The study found more
collagen ‘scar’ tissue or fibrosis, degenerative red cell/monocyte
accumulation (haemosiderin) and vascular remodelling in the
airsac lining vessels in both the capillaries and drainage veins, as
well as the separating elastic (interstitial) tissues. The diameter
of the supply and drainage vessels were decreased by greater
than 50% during the healing process. This could be the reason
for the poor performance after a ‘bleed’, with increased lung
fluid build-up (oedema) and lower oxygen uptake.
Editor’s Note: The study indicated that restriction of the
veins in the area most effected by a ‘severe’ bleed, may
underlie the other damage seen after a ‘bleed’ and reduce
subsequent performance by affecting lung efficiency in
the long term. Restricting water intake for 6 hours prior
to racing may also help to reduce lung oedema and fluid
retention.



i'd want to prevent a bleed that would cause lasting damage. what would you tell me to do instead, if i was worried about such a thing, knowing the drug has medical uses and can prevent unnecessary damage to a horse that someone potentially invests a lot of money in?
if your concern is that it could move a horse up, but most horses already use it anyway, doesn't that negate any possible move-up? and many articles i've read say it's not a performance enhancer. is that an opinion, and not a proven fact? from what i've read in various studies, it's not a fact.