Anti LasixJockey Club Blowhards, Comments?

[miff]

DRF:

A study funded in part by North American racing groups and conducted using South African racehorses has indicated that furosemide, the diuretic administered prerace to about 90 percent of all horses racing at North American tracks, plays a significant role in reducing the severity of bleeding in the lungs.

The study, conducted by researchers at Colorado State University, the University of Melbourne in Australia, and the University of Pretoria in South Africa, involved postrace tracheal examinations in 167 horses that were administered either a saline solution or furosemide - which is marketed under the trade name Salix but is better known as Lasix - prior to performing in races at Vaal Racecourse in South Africa. The researchers found that horses administered furosemide were far less likely to suffer \"severe\" episodes of bleeding than those that were injected with the saline solution.

The conclusions appear to confirm results that had previously been largely anecdotal. In the United States and Canada, the only two major racing jurisdictions that allow the use of furosemide on race day, veterinarians have long contended that the drug effectively reduced the severity of bleeding, or exercised-induced pulmonary hemorrhage, but previous studies had relied only on laboratory results, rather than the study of horses under actual racing conditions.

\"It does back up the clinical impressions of practitioners on the backstretch that furosemide does help in the reduction of EIPH,\" said Dr. Scot Waterman,the executive director of the Racing Medication and Testing Consortium, a North American research group that co-funded the study. \"The current literature is equivocal about that.\"

The researchers used a scale from 0 to 4 to grade the severity of bleeding in the postrace tracheal examinations, with a 0 indicating that the horse did not show any evidence of bleeding and a 4 indicating the most severe episode. The researchers used the results from horses that were administered furosemide prior to one race and saline solution prior to a different race.

Though the results did not show a significant difference in the percentage of horses that experienced a bleeding episode rated a one by the researchers, the postrace tracheal examinations of horses that were administered furosemide were far more likely to be rated a 0 and far less likely to be rated a 2, 3, or 4. In fact, no horse that was administered furosemide had a postrace tracheal examination that rated either a 3 or 4, whereas approximately 10 percent of the untreated horses received a 3 rating. Two postrace tracheal examinations of the 152 conducted for untreated horses were rated a 4, or 1.3 percent.

In addition, the researchers concluded that \"81 of the 120 horses that had EIPH after administration of saline solution had a reduction in EIPH severity score of at least 1 when treated with furosemide,\" according to the study.

Because furosemide is a diuretic, many veterinarians have theorized that the drug reduces capillary pressure in the lungs and makes blood vessels less likely to burst. The study did not seek to determine why furosemide reduces bleeding, however.

Consistent with the clinical effects of a diuretic, the study showed that horses administered furosemide experienced a much greater weight loss after administration than horses that were not injected with the drug. According to the study, treated horses lost an average of 27.9 pounds between the injection and a weight measurement following the race, while untreated horses lost an average of 11.9 pounds.

\"However, weight loss does not appear to be directly related to the mechanism by which furosemide prevents EIPH,\" the study\'s authors wrote, \"in that we did not identify an association between amount of weight lost and prevention of EIPH in the present study.\"

The most rigorous study about the effects of furosemide on racing performance - conducted in 1999 using an analysis of past-performance data - had concluded that horses treated with the drug ran faster than untreated horses. That study, which was co-authored by one of the co-authors of the just-released study, Dr. Paul Morley, did not delve into it

[TGJB]

Looks like this ran in 2009, no? Waterman hasn\'t been in that job for a while.

[miff]

.....and more confusion




Monday, Dec 16, 2013

DRF
Breeders\' Cup furosemide study raises questions
By Matt Hegarty


A study examining juveniles that raced on the Nov. 1 and 2 Breeders' Cup cards at Santa Anita has contradicted a previous study showing that the legal raceday medication furosemide is effective in mitigating the incidence and severity of bleeding.

The study last month, which entailed the endoscopic examination of 41 horses that raced without furosemide and 14 horses that raced on the medication, showed that horses treated with the drug had a statistically significant higher incidence and severity of bleeding than the untreated horses. A 2009 study on horses running in South Africa, which was conducted in a more scientifically rigid manner, showed just the opposite, confirming what some horsemen see as anecdotal evidence for the efficacy of the drug in mitigating bleeding.

Though the authors of last month's study cautioned that the study's limitations make the interpretation of the results difficult, the findings are sure to inflame an already contentious debate on the use of raceday furosemide, which is legal in all North American racing jurisdictions but prohibited in most other major racing countries worldwide. Supporters of furosemide use have said that the drug is an effective treatment for bleeding in the lungs, while critics have said the drug's efficacy is vastly overstated and that the use of the drug on raceday in North America is exacerbating the sport's public-perception problems.

The study, which was paid for by Breeders' Cup, examined a total of 55 horses that raced during the two Breeders' Cup cards. Juveniles running in the five Breeders' Cup races for 2-year-olds were prohibited from running on furosemide under a rule that was allowed to expire this year, while horses in two non-Breeders' Cup races, for California-bred juveniles, were allowed to race on the drug.

According to the study, 15 of the 41 untreated horses showed evidence of bleeding, or 37 percent, while 10 of the 14 treated horses, or 71 percent, showed evidence of bleeding (any fleck of blood visible on endoscopic examination of the trachea, the tube running from the lungs to the nose and mouth).

The study also found that five of the 14 horses, or 36 percent, treated with Lasix were scored as having bled in the higher ranges of the scale, compared with only three of the 44 untreated horses, or 7 percent. That result strongly contradicted the South Africa study, which found that horses treated with furosemide were far less likely to suffer "severe episodes of bleeding" than those injected with a saline solution.

Veterinarian Nathan Slovis, who oversaw last month's study, said on a conference call that he had expected to find that the treated horses had lower incidences of bleeding, along the lines of the South Africa study. He cautioned that the Breeders' Cup study looked only at "the best of the best," and said that the South Africa study and the Breeders' Cup study were "apples and oranges."

"You cannot correlate our study to the South Africa one," he said, acknowledging that the South Africa study had far fewer limitations. "You cannot compare the two."

When asked why the result appeared to so strongly contradict the South Africa study, Slovis said that the Breeders' Cup study had a built-in selection bias because owners of the horses that raced without furosemide knew beforehand the drug would be prohibited in the Breeders' Cup races and may not have run horses that were bleeders.

Alternately, the horses running in the two Cal-bred stakes races included in the study "may be the horses that needed it," Slovis said.
"It may be the caliber of the horse, different training methods, different environmental factors, it could be any number of factors," Slovis said.

Breeders' Cup decided to undertake the study after the Breeders' Cup board, in a controversial vote, decided earlier in the year to suspend the ban on the drug because of concerns that horsemen would withhold approval of wagering on the Breeders' Cup simulcast signal if the ban was not rescinded for 2014. Horsemen's groups are the most ardent supporters of raceday use of the drug.

Craig Fravel, the chief executive of Breeders' Cup, said the results "pose more questions than answers" and he said that the issue of raceday furosemide requires more study. He called on other industry organizations to support more research.

The question of whether furosemide is truly effective in mitigating bleeding is not the only mystery surrounding the drug. While some have theorized that the drug, a diuretic most commonly known by its former trade name, Lasix, could be effective by decreasing blood pressure in the lungs, the means of its efficacy is unknown.

"We really don't have any data on how Lasix works," said David Richardson, a Breeders' Cup director and the chief of surgery at the University of Louisville. "You can also argue that we need a little more basic science ... and what the side effects are."

[kekomi]

yeah this is from 2009--i pulled the actual journal article a few years ago, it\'s online now.

you can read it here: http://www.rmtcnet.com/resources/Study-_JAVMA_Furosemide.pdf

problems with the study:

despite 5 years, the study has not been replicated.

the sample size is too small to draw conclusions from.

because the data doesn\'t indicate each horse\'s individual lasix vs. saline outcomes, the results are meaningless. there is no way to evaluate the likelihood of causation, as opposed to just correlation. we don\'t know if any of the horses were a lasix level 2 and a saline level 0. we don\'t know if the level 1\'s were basically the same horses each time. and even if both saline level 4\'s were lasix level 0\'s, that result could be completely spurious. there\'s no way to tell.

the tests were not conducted over a long enough time period to establish each horse\'s average. there is no way rule out that horses don\'t bleed at different rates--some races not at all, some races a little, some races a lot. there is no way to rule out that the results were not the result of a horse\'s bleeding cycle, as opposed to lasix administration.

one group ran lasix first, saline second; the other ran saline first, lasix second--this makes the two groups incomparable. this is plain bad science--the article would have been rejected outright from a human publication because of this alone. there is no way to rule out that the order of the lasix v saline didn\'t make a difference. maybe horses that have raced on lasix in one race, have a higher chance of bleeding next race out? who knows? this article certainly doesn\'t tell us.

and finally...the numbers break down too perfectly to be chance--and i don\'t mean this proves lasix\'s efficacy. even if lasix does prevent bleeding, the breakdown here is too \"neat\" for it to be the random outcome of an experiment. in fact the break down is so near to perfect, the 68.5 looks almost like someone altered it a little just so that fact that the numbers showing each each level dropping almost exactly by half wouldn\'t be so obvious (just slide 4 over to level 3 and 2 over to the empty level 4...you wouldn\'t need a scope to see level 4, but there is no mention in the article of any horses bleeding visibly by the nose...):

65 horses were level 0 on lasix; 32 on saline.

67 horses on saline were level 1; 75 lasix: 67/2 = 33.5 + 32 = 65.5

35 horses on saline were level 2; 12 on lasix: 35 + 33.5 = 68.5

16 horses were level 3 on saline; none on lasix.

2 were level 4 on saline; none on lasix.

[BitPlayer]

Kekomi -

It would be rare in an academic journal to provide all the detailed data you say is missing.  Summarized results with statistical analysis are the norm.  If you have academic credentials, the corresponding author (Hinchcliff) should, however, be willing to provide detailed data to you upon request.  If you don\'t, he may still be willing to provide the information.  If you have serious concerns about the validity of the study, you should contact him.  I would tread gently in the area of implying that the data was too neat to be true.

The absence of a second study probably says more about the absence of money to pay for it than about the validity of the results.

Compared to this study, the Breeders Cup study is a joke.