THE SPORTS DOCTOR- Polo poison: What probably caused this sports disaster

When 21 Venezuelan polo ponies died last weekend, many people blamed steroids. And why not? After all, when it comes to performance enhancing drugs in the world of horseflesh makes the Tour de France look like a church picnic. But the fact remains that when 21 horses die and there's not a barn fire involved, steroids aren't the reason. The actual culprit may be much more insidious in its mundanity.

Last year, a lot of people lost money betting on Big Brown to win the Belmont Stakes. Were it not for a crack in his left front hoof, surely Big Brown would have been the first Triple Crown winner since Affirmed in 1978. And why not? Whatever Big Brown's pedigree lacked, his trainer, Rick Dutrow, was happy to provide.

Luckily for Dutrow, who has been fined or suspended at least once a year since 2000 for doping violations, Wintrol, the anabolic steroid with which he injected Big Brown, was legal in 28 of the 38 states with racing, including those with the Triple Crown.

The use of steroids and medications in horse racing is so pervasive that Congress held a hearing about it last June. Since then several states, including Kentucky, have approved sweeping steroid bans for racehorses and many hope US, Polo will follow suit. 

If you've ever owned horses, you know nothing is more dangerous than what they ingest. You shouldn't feed horses first-cut hay that isn't treated with a preservative, because it often doesn't dry properly and develops mold, which can kill a horse. Lou Lopez, coach of Virginia Polo, recently threw away two bales of hay. "I opened them, and the mold just flew out." 

And hay is just the beginning. Sudangrass and sorghum-sudangrass hybrids can cause death; older varieties of tall fescue may contain an endophyte fungus that causes severe health problems when eaten in summer– even common plants can poison horses. Is it any wonder many owners choose to purchase feed instead?

Most horse feed is produced on the same machines that process cattle feed: a dangerous gamble. A 1999 case of poisoning ended up in Virginia's courts when twenty horses were poisoned by a mistaken delivery of cattle feed laced with the antibiotic lasalodic. All twenty horses colicked, and five died. Lasolodic is an ionophore, a class of additives commonly fed to cattle to improve feed efficiency and promote growth. 

The manner in which the Venezuelan polo ponies died is shockingly similar to that of another type of ionophore poisoning: Rumensin.

In 2005, Tennessee Farmers Cooperative recalled four lots of horse feed that was contaminated with of Rumensin. The following year, Western Stockmen's issued a recall of its Pride Mature Horse Feed, lot 7701-05030, for the same reason. 

According to a local equine doctor, plants are required to run three waste batches of untreated feed through a mill when switching from cattle to horse feed, but only takes 80 parts per million of Rumensin to cause sudden heart failure in a horse.

The polo team's vet, Dr. James Belden, cited the immediate cause of death in the 21 horses as pulmonary edema and cardiac arrest. Before they died, the horses acted "dizzy and disoriented." Rumensin's own data warns of  "degenerative and reparative tissue changes, electrocardiogram changes, congestive heart failure and skeletalmuscle changes, elevated blood enzymes" in horses that ingest it.

Down at the US Open, it's not the polo that smells. Two FDA inspections of the Western Stockmen's feed mills (available under FOIA) reveal that safe practices were not in place, recommended practices were not followed, and horse feed was routinely contaminated with Rumensin. According to every vet, horse trainer and breeder I asked, those 21 Venezuelan horses must have died from poisoned feed, and all mentioned Rumensin by name. One vet said he "would be the most shocked person in the world" if it turned out to be anything else.

Unfortunately, there is no tissue test for Rumensin, so chances are if that is the cause of death, we may never know.

Of course, tainted feed is not the only thing that leads to heart failure in horses: bad medicines, moldy bedding, even muscle liniments could be at fault. The bottom line is that someone somewhere sold a poisonous substance to the Venezuelan polo team, and 21 horses died as a result. Everything those horses ate, drank, slept in, or were rubbed could be on the market right now. You could very well have it in your own barn and you don't know it. 

Not so mundane, is it?