Bred for Speed ... Built for Trouble

By Jeffrey Kluger

Much as we try, we can't stop humanizing our horses. This one's got the heart of a champion; that one has the guts of a mudder. We don't really know if there's anything behind all that anthropomorphizing. But we do know that a horse can suffer as we do--feeling pain, fear, confusion and shock. All of that was on display at Pimlico Race Course in Baltimore, Md., when Kentucky Derby winner Barbaro shattered his right rear leg at the Preakness Stakes just moments out of the gate. It was the most stunning racehorse disaster since the death of the famous filly Ruffian in 1975 and perhaps the most gruesome sports injury to any creature since the nationally televised sight of Washington Redskins quarterback Joe Theismann's leg snapping like a bread stick in 1985. But there's something about a Thoroughbred coming undone--something about that exquisite engine of muscle, bone and congenial will crashing down--that moves us. In the days since Barbaro's accident and surgery, the horse--now housed in a 13-ft. by 11-ft. stall at the University of Pennsylvania's George D. Widener Hospital for Large Animals--has received a flood of cards he can't read, endless baskets of fruit he won't finish, and flowers he may or may not smell. Tens of thousands of dollars and untold hours of effort will be spent on his care, all for an animal that--his potential $30 million in breeding fees notwithstanding--was already insured up to his velvety ears.

But we love our horses--so much that we may be wearing them out. Racehorses sustain lethal injuries an average of 1.5 times in every 1,000 starts, according to some studies. A millennium after the sport was born, we're breeding horses to finer and finer tolerances, racing them earlier and harder and producing an animal that may be a thrill to watch but is increasingly hard to keep whole.

"The market wants a faster, earlier-maturing horse," says Dan Rosenberg, president of Three Chimneys horse-breeding farm in Midway, Ky., "but there is an incompatibility between speed and durability." Not everyone in the industry agrees, but injuries like Barbaro's raise the question anew every time they occur.

Horses are undeniably born to run, a survival strategy that befits a prairie herbivore with neither fangs nor claws. While a lot of animals are fleet of foot, horses achieve their speed more elegantly than most, starting with their disproportionately long legs. Limb length usually means bulk, since it takes a lot of muscle to move long bones. But muscles add weight, and weight reduces speed. The horse solves that problem by packing its musculature in its upper body, then transferring that power down to the legs with an elaborate rope work of tendons and ligaments that absorb shock as the animal runs and then snap the leg back to reuse the energy on the next stride. The system works well, but it does leave the legs exceedingly vulnerable to injury because when a break occurs, the blood vessels embedded in the limbs can torque and tear.

Ingenious as the horse's overall design is, humans couldn't resist tinkering with it. About 300 years ago, breeders began crossing fleet European mares with strong Arabian stallions, producing a faster animal that could run longer distances. All Thoroughbreds today are descended from just three Arabian males--the so-called foundation sires.

But even superhorses can be pushed to the limit. With breeding fees as high as they are, owners are tempted to put their best horses on the track sooner and retire them to reproduce earlier. Secretariat, the 1973 Triple Crown winner, had 21 career starts. Smarty Jones, winner of the Derby and Preakness in 2004, logged only nine. Rank-and-file racehorses start early too but have harder careers. Winter used to be off-season for racing in the U.S., but now horses are trucked to courses where the weather is warmer and the wagering can continue. What's more, U.S. fans have grown to prefer shorter, faster races, so breeders produce animals suited to sprints. The faster you move, however, the harder you can fall.

Still, there is no proof that horses bred for speed are more injury prone. Are today's Thoroughbreds more fragile? "Absolutely not," says Widener director Dr. Corinne Sweeney. Owners do periodically outcross, bringing in new breeding partners to freshen the gene pool. But that is merely an effort to boost performance, not build a sturdier animal.

Trainer Bob Baffert, whose horses have won the Derby and Preakness, insists that if injuries are on the rise, it's only because the number of racehorses is too. Fifty years ago, 10,000 foals were registered annually; today that figure is 34,000. TV contributes to the sense that injuries are on the rise, broadcasting the worst ones over and over. Besides, anytime you've got 1,200 lbs. of animal on the move, accidents will happen. "I've seen horses in the paddock injure themselves," Baffert says. "Barbaro just stepped wrong."

When a horse does get hurt, it's nice to have a repair shop like the Widener Hospital on hand. As would any doctor, one of the first things surgeon Dean Richardson did when Barbaro arrived was feel his patient's pulse--in several spots along the injured leg. Weak pulses or a cold foot would have meant that blood-vessel injury had occurred and the limb was lost. "He had good, strong pulses, and his foot was warm," says Richardson. "I was thrilled."

One day after the surgery that repaired his limb, Barbaro was standing--gingerly--with the aid of a cast, but his situation is still touch and go. Infection remains a risk, as does laminitis, injury to the tissue between hoof and bone that can affect the healthy left hind leg, which now bears more weight. To minimize the risk of reinjury, Barbaro will be confined in his stall for several months. The goal is not to get him fit enough to race; that option ended shortly outside the gate at Pimlico. What he does need is an ankle strong enough to support him on his hind legs for mating. (Artificial insemination is forbidden for Thoroughbreds, in part to avoid overworking a few blood lines.) "We want Barbaro to have a reasonable quality of life," says Richardson. "I think that would be enhanced if he's able to have sex with a lot of pretty mares."

That would be the ideal outcome for Barbaro. But there are plenty of other, less-fussed-over racehorses that come to a sorrier end. Breeding and racing are multibillion-dollar businesses, and they're not likely to get smaller any time soon. The people who raise and run the horses do care about them deeply, as Barbaro's attentive owners show. The industry as a whole, however, may need to love its animals just a little bit more, if only to push them a little bit less. [This article contains a complex diagram. Please see hardcopy or pdf.] POWER ZONE

Horses are designed to run. All their muscles are concentrated in the upper body, supported by long, thin legs. The massive hind muscles of a Thoroughbred drive enormous stress onto ankles not much bigger than a human's

Gluteal muscles

Biceps muscles DANGER ZONE

The lower parts of the legs have no muscles at all, just a structural network of bones, tendons and ligaments. That makes the blood vessels particularly vulnerable to tearing when a bone breaks. If that happens, there's little hope

Metatarsal vein Cannon Metatarsal artery Sesamoid Hoof Pastern

Cannon 1 large, other small fractures Sesamoid Multiple fractures

Fetlock joint Dislocated

Pastern More than 20 fractures

THE INJURY Barbaro's disastrous misstep shattered three bones and dislocated a joint. Luckily, he did not injure his veins or arteries. Now he must fight off infection during recovery SAVING BARBARO 1 In a 4.5-hour operation, surgeons inserted 27 screws and a 15-in. (38 cm) plate in and along the broken bones. The bones will fuse over time. Barbaro should be able to walk again, even though his ankle won't bend Cannon Sesamoid Pastern 2 To keep him from thrashing about and reinjuring himself when the anesthetic wore off, Barbaro was lowered into a pool of water for about an hour Raft keeps horse dry 3 Once he was fully awake, Barbaro was hoisted from the pool and taken by monorail to a recovery area. He'll be confined to his stall for several months Sources: Corinne Sweeney, DVM, New Bolton Center, School of Veterinary Medicine, George D. Widener Hospital for Large Animals; Atlas of Topographical Anatomy of the Domestic Animals, Vol. 1 ; Wildlife Conservation Society, Bronx Zoo; Animal Painting and Anatomy, by W. Frank Calderon (Dover, 1975) Graphic for TIME by Ed Gabel; reported by Kristina Dell

With reporting by David Bjerklie/Kennett Square, Amy Lennard Goehner/New York, Alice Park/New York