A consensus among equine researchers and surgeons has developed that legal medications and cortisone shots have become overnight solutions that, over time, leave a horse vulnerable to a catastrophic breakdown later in its career. Research suggests that the majority of racehorses that fatally break down have a pre-existing injury.

Nancy Heitzeg, a professor at St. Catherine University in Minnesota, has attempted to track all horse racing fatalities in the United States. She calculated that there had been about three breakdowns a day nationwide since last year’s Kentucky Derby.

In America, racehorse fatalities have occurred at the rate of 1.47 per 1,000 starts for synthetic surfaces, and 2.03 per 1,000 starts for dirt tracks, according to Mary Scollay, a veterinarian and equine medical director for the Kentucky Horse Racing Commission, who conducts research for the Jockey Club.

In England, the average risk of fatality is much lower, between 0.8 and 0.9 per 1,000 starts. In Victoria, Australia, there have been studies that have reported the risk of fatality between 1989 and 2004 at 0.44 per 1,000 starts.

Corticosteroids can be injected into a horse’s joints and are prevalent on the backsides of American tracks. They are often given within days of a race, especially in the lower levels of racing where horses tend to be less sound and opportunities to race are fewer. In essence, it is a way to help a sore horse make the starting gate.

“These are strong drugs and have therapeutic benefits,” said Dr. Wayne McIlwraith, a surgeon and leading researcher on corticosteroids at Colorado State University. “The question we need to answer: When are we helping a horse, and when are we desensitizing pain to dangerous levels?”

This will be the first Kentucky Derby where anabolic steroids are expressly prohibited, which is a victory for the industry’s Racing Medication and Testing Consortium, which has also pushed through uniform medication rules in 32 of the country’s 38 racing jurisdictions.

Many within the sport would like to see the medication rules go even further — to eliminate all but the essential medicines that treat a horse for an illness or injury.

“Sometimes there is a conflict for what is best for the horse and what’s best for the owner, and what’s best for the trainer or the vet,” said Rick Arthur, the equine medical director of the California Horse Racing Board. “The easiest way to regulate something is to take away the opportunities for bad judgments.”

Mac Robertson, the trainer of Win Willy, is the son of a horse trainer and grew up at third-rate tracks throughout the Midwest where horses were injected because horsemen needed to feed their families. Now, as he has risen to the upper levels of the sport, he said he was disappointed that some trainers and owners treated their horses as livestock, or, worse, as commodities.

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“I’ve watched my favorite horse break his leg when I was a kid and I know how much that hurts,” Robertson said. “We should get rid of all medications because they are bad for the horse, and it’s bad for the breed. If a horse is not healthy, he should not be running.

“But we have too many people hold them together with drugs so they can win races and go to the breeding shed and make money. If they won on drugs, they really weren’t the best, and their flaws are going to keep being passed on.”

Porter will hardly feel outgunned when he sends Friesan Fire to the starting gate Saturday. His colt has received nothing but vitamins and electrolytes since arriving in Kentucky from Louisiana, though he has been treated by a chiropractor. It is a regimen both Porter and his trainer, Jones, are comfortable with.

As Eight Belles taught them, horse racing is dangerous enough under the best conditions. Then as now, they said, they could sleep at night with their decisions.

Porter, however, is disappointed that horse racing has not gone further in eliminating medications and conducting itself more transparently.

“Everyone who participates in this game should be taking care of these horses,” he said. “We’re the ones that speak for them."

This article, Many Derby Owners Silent on Drug Issue originally appeared at The New York Times.

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