McIlwraith told Bloodhorse.com that there is no data to suggest females suffer more catastrophic injuries than males. Nor, he said, is there any evidence that 2-year-olds are injured more than 3- or 4-year-olds. Four-year-olds actually have the highest incidents of catastrophic injuries, he said.
Added Bob Baffert, who has trained winners in eight Triple Crown races: "It's not even an issue. I come from the world of quarterhorses. There, the fillies beat up on the boys all the time."
Rick Arthur, the equine medical director for the California Horse Racing Board, said fitness is the real issue.
"When a 3-year-old gets to the Kentucky Derby, it becomes a real test of stamina," he said. "The bones are ready, but they have never run a mile and a quarter. That's what makes it such a test."
Barbara Vanlangendock, a Florida bloodstock agent, said, "You have to look at the animals individually. I have tons of owners who don't race their horses until they are 4."
The New York Times recently cited statistics that addressed the relative durability of horses. It said that, in 1960, thoroughbreds made an average of 11.3 racing starts in their career. Last year, that average was 6.3.
Arthur said that North America has gone increasingly toward the shorter races, six- and seven-furlong dashes, because horses are bred for that now.
"For a long time, the thoroughbred was bred as a horse that can go the distance and take your breath away," said Tom Bowman, general manager and partner of Northview Stallion Station in Chesapeake City, Md. "We are starting to sacrifice some of those qualities for a short racing career and cheap speed overall."
Arthur pointed out that the June 7 Belmont Stakes will be the only time a 3-year-old will go a mile and a half in this country.
That is one difference from foreign racing, he said, where breeding leans more toward durability.
"When Stevie Cauthen went over to Europe years ago to race," Arthur said, "he was criticized because he always went to the lead early. That was our style, not theirs. They never do that in Europe."
Cauthen rode the last Triple Crown winner, Affirmed, in 1978.
Another major difference involves doping. Horses may run at North American tracks 24 hours after being given therapeutic drugs such as Lasix or Butazolidin. (Lasix is a diuretic that treats bleeding and reduces blood pressure; Butazolidin, or Bute, is an analgesic and anti-inflammatory.) Such doping is banned everywhere outside of North America. Critics say these drugs can mask injuries and contribute to breakdowns.
