Latest EIPH and Lasix study has a precedent in Brazil

The latest “Lasix Study,” commissioned  by Breeders’ Cup Ltd. and conducted by Hagyard Equine Medical Institute, was released yesterday with enough “evidence” for those for and against the use of race-day furosemide (Lasix and Salix) for EIPH (exercise-induced pulmonary hemorrhage) treatment to ring their respective bells. And the bells were ringing yesterday on Twitter from the moment Jim Gluckson of Breeders’ Cup issued an email press release to turf writers on the findings.

The complete results of the study are available here; the long and the short of it—which examined and published the post-race endoscopies of two-year-olds racing on Breeders’ Cup weekend at Santa Anita—can be boiled down to this paragraph in the release:

“Specifically, the percentage of horses that were observed to have some level of EIPH was significantly greater among furosemide treated horses (71%, 10 of 14) compared to non-treated horses (37% 15 of 41).  Similarly, the treated horses showed significantly higher likelihood to have a severity scoring greater than two on a scale of zero to four (four being most severe) with 36% (5 of 14) scoring higher than two while the untreated group had only 7% (3 of 41) that were scored at an EIPH level greater than two.”

The anti-Lasix crowd used these findings to argue that racehorses don’t benefit from furosemide; the pro-Lasix  lobby, perhaps not quite as vociferous on Twitter and in the press simply because its constituents—trainers, mostly—aren’t as prone to tweet or write, scoffed at the sample size. Both sides agreed that more research was needed, and each side, judging by the veneer of satisfaction in tweet commentary, walked away as if victorious.

A little history and the study from Brazil

Before the modern-day endoscope arrived in the late 1960s, “bleeders” were simply those horses that exhibited epistaxis—bleeding from the nostrils. Those that weren’t visible bleeders were referred to as horses with “bad air” by some horsemen, or simply as slow horses that didn’t put out by others.

The endoscope, of course, changed some of the thinking; by the early 1970s bleeders were classified by endoscopic examination, and the loop diuretic furosemide that had been developed in the 1960s and had reportedly been administered by Dr. Alex Harthill to none other than subsequent super sire Northern Dancer in the 1964 Kentucky Derby, became legal in several states.

What Doc Harthill and other vets had discovered by chance was a side effect of Lasix, that the drug intended for edema and heart failure in humans apparently also helped equine bleeders and those with “bad air,” very much in the way, for example, Sildenafil (Viagra) was originally developed as a treatment for high blood pressure but by coincidence was found to aid in erectile dysfunction (ED).

Scientific literature explains clearly that Viagra doesn’t work uniformly in the treatment of ED—the drug doesn’t “cure” all instances of ED and has various levels of success depending on a variety of factors—and  most horsemen are aware that Lasix isn’t a magic bullet for EIPH (many will use with adjuncts and others have used bronchodilators in conjunction as well), but most seem to prefer its usage as a means of controlling EIPH and most also seem to feel that EIPH will appear at one time or another, especially as horses age.

This brings me to a Lasix/EIPH study from Brazil from 2006 that had a sample size significantly greater than that used by Hagyard but with results quite similar to what was found by Hagyard’s researchers.

Here are salient points from the abstract (there’s a spelling mistake: “HPIE” for “EIPH”; “FUR” refers to furosemide:

A) “… 2118 post race respiratory endoscopies were recorded, in a total of 1003 individual horses. All horses in the study were certified bleeders (deemed positive by registered veterinarians following one or more endoscopies) and were administered FUR prior to each race. Data was analysed using both ordinary logistic regression and multiple logistic regression.”

B) “… despite the use of FUR, the majority (62%) of horses continued to display some degree of haemorrhage.”

C) “CONCLUSIONS: There was a tendency for horses that remained positive despite the use of FUR to finish unplaced in a race. Horses which had a significant reduction in bleeding and became HPIE negative after the use of FUR, tended to finish in top positions. It was not possible to determine a pattern of severity of EIPH in horses with more than one endoscopy. Further studies are required to improve our understanding of this syndrome and its correlations to performance in the racing Thoroughbred, together with the role of FUR and its possible enhancing performance effects and efficacy in consistently diminishing EIPH.”

These researchers, too, have called for more studies, but perhaps one of their findings does corroborate what those from Doc Harthill to present-day trainers have said anecdotally at least (though there are other studies, like this one, that say furosemide is effective in treating EIPH): that those horses in which furosemide  had reduced bleeding ran better.

And because horsemen seem to feel that Lasix reduces some EIPH, their powerful national lobby will continue to fight efforts by others to do away with the race-day drug, and that is the impasse, isn’t it?

Latest EIPH and Lasix study has a precedent in Brazil

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