As a biology student with a horse racing blog, I feel the need to have a go at this whole Lasix controversy that the Breeders’ Cup started by announcing it would be fading out the use of the drug during the championship, with a ban in place by 2013.

If you’d like the short version: go, BC, go. Furosemide (Lasix’s actual chemical name) has well-documented dangers associated with it, and even used properly in the best-case scenario, it masks deeper-running problems that will be a detriment to the breed if cycled in the gene pool. Furthermore, there are better, non-chemical ways to improve respiration and soundness of respiratory soft tissues.

Long version, ho.

To find the most common side effects of furosemide, one need look no further than Wikipedia. Listed amongst possible risks associated with overdose are dehydration, change in drinking patterns and urination, seizures, gasto-intestinal disturbances (colic), kidney damage, lethargy, collapse, and coma. Now, it should be fairly obvious to a person with an ounce of critical thinking that these are risks associated with overdose, and not responsible use, right? Well… yes, and no. Even on its best day, furosemide is a difficult compound for the kidneys to process and dehydration and electrolyte imbalance are extremely common. This can and does result in post-race weight loss, which is probably responsible for the “bounce” phenomenon by which racehorses are noted to run poorly one race after a particularly good performance.

An observation of this kind I can easily dig up is from the career of Super Saver, who was raced sparingly before the Arkansas Derby. After running quite well in that final prep, he won the Kentucky Derby with considerable ease. Unfortunately, he then lost what looked like half of his body condition, finished up the track in the Preakness and never ran well again. Consider what this means in the context of medication: his body was used to light work, and a dose of furosemide every five to six weeks or so. Then, he gets three doses in five weeks, from Oaklawn to Churchill to Pimlico. Is it any wonder that he lost so much weight?

For the record, I’m not the first person to make the connection between the dehydration side-effect of furosemide and the long interval in the modern racing schedule, but I mention it here because it’s an important angle to consider. A horse administered furosemide on race day will, as a result of the systemic stress exerted by the drug, take longer to recover physically after a race. Because of this, his training will be lighter immediately following an outing. On average, a horse who races on furosemide will train less than one who races drug-free. See where I’m going with this? As usual, it all links back to my usual rants about soundness and tissue loading. The positive effects of frequent, fast sprints at a young age on bones and on the soft tissue of the respiratory tract have been well documented, and I’ve expounded on them in the past, so I’m not going to do it again. All I will say is that the use of Lasix robs a horse of developing anywhere near the soundness and endurance he otherwise might achieve.

Another angle to consider is the masking effect of furosemide. Yes, it might prevent bleeding in a horse susceptible to bleeding. But on the other hand, if every horse races with Lasix, how are we to know which ones are the bleeders? In many cases I imagine one cannot know. These horses are then cycled right back into the gene pool, where they pass on their weak soft tissues to offspring. I shouldn’t have to explain why this is a bad thing.

Finally, there are better ways to help a bleeder, or any other horse for that matter, breathe easier. One method which is gaining popularity and which I personally think will be a boon to trainers who consider it is the use of nasal strips, as developed by FLAIR. In theory (and as demonstrated by several studies), nasal strips tents the skin above the nasal valve, increase the diameter of the nasal passages, decrease air resistance and increase the volume of air taken in with each breath. Glowing testimonials come from champions in every equine performance field, from polo to trick riding to international eventing. One recent high-class wearer is Mighty Caroline, winner of the GIII Sorrento Stakes (for two-year-old fillies) at Del Mar. Another way to improve the structural integrity of the respiratory tissues, as I said, is to mildly stress them out once in a while. Bodies are good at compensating for and adapting to things like that.

So basically I am of the opinion that Mike Repole and everyone else who’s whining about the BC’s move should shut up and read Wikipedia. And maybe do a class in drug action, ’cause this one’s a doozy.

Oh, and it’s worth mentioning that Affirmed, the last Triple Crown winner, raced before the advent of Lasix.

Just so you know.