Cairo Cat (left) rallies to defeat Tight Ten in the Iroquois Stakes (gr. III) at Churchill Downs - Coady Photography

Cairo Cat (left) rallies to defeat Tight Ten in the Iroquois Stakes (gr. III) at Churchill Downs – Coady Photography

If you’ve followed horse racing for any amount of time, you’ve probably heard phrases like “first-time Lasix” or “racing without Lasix.” But what does it all mean?

For the most part, racehorses in North America are treated with Lasix a few hours prior to post time in order to lessen the likelihood of them suffering from exercise-induced pulmonary hemorrhage, which can significantly affect their performance in a negative way. It’s considered a preventative measure, though not all racehorses necessarily need to race on Lasix—in fact, it’s prohibited in most major racing nations.

Many racehorses race on Lasix throughout their careers, though some trainers prefer to start their young runners without the medication and add it later if needed, and that’s where handicappers can occasionally capitalize on lucrative opportunities.

One such trainer is Kenny McPeek, who is perhaps best known for conditioning the Grade 1-winning millionaires Take Charge Lady, Harlan’s Holiday, and Golden Ticket. McPeek isn’t afraid to race juveniles without Lasix, but once they’ve gotten started and are ready to stretch out in distance and step up in class, McPeek will frequently choose to treat them with Lasix for the first time… and that’s when handicappers need to take note!

Two examples from 2018 clearly illustrate why this is an angle to keep an eye on. During the summer meet at Saratoga, McPeek debuted a promising two-year-old named Cairo Cat, who finished eighth in his first start on turf before switching to dirt and winning a seven-furlong maiden special weight in narrow fashion.

For Cairo Cat’s third start, McPeek shipped him to Churchill Downs to contest the 8.5-furlong Iroquois Stakes (gr. III), a prep race on the Road to the Kentucky Derby. Cairo Cat was 17-1 in the betting, but notably, he was scheduled to race on Lasix for the first time. Thanks in no small part to a perfect ground-saving trip, Cairo Cat rallied strongly in the final furlong to win against a deep field.

Three weeks later, McPeek made a similar move with Restless Rider, a very promising filly who had won the Debutante Stakes at Churchill Downs before finishing second in the Spinaway Stakes (gr. I) at Saratoga. That promising form stamped her as the favorite for the 8.5-furlong Darley Alcibiades Stakes (gr. I) at Keeneland, which would mark her debut in a two-turn race. In preparation for that stiff test, McPeek treated Restless Rider with Lasix… and she won decisively by 2 ½ lengths.

According to statistics from DRF Formulator, over the last five years, Kenny McPeek has compiled a stellar 5-for-14 record with juveniles racing on Lasix for the first time in a graded stakes race, generating a 36% win rate and a terrific $5.02 ROI. For good measure, McPeek’s record also includes a couple of high-priced second-place finishers, including Signalman (10-1) in the 2018 Claiborne Breeders’ Futurity (gr. I).

Suffice to say, the next time you see a McPeek-trained juvenile racing on Lasix for the first time, it might be time for a confident win bet at a nice price!