Secretariat, the horse with heart, inherited the ‘X factor’

As Valentine’s Day approaches, thoughts naturally turn to matters of the heart. For fans of Virginia native and triple crown winner Secretariat, that has a two-fold meaning.

Secretariat continues to hold a place in fans’ hearts—and the record books—40 years after his spectacular victories in the Kentucky Derby, Preakness and Belmont Stakes. Moreover, it was his own enormous heart that helped him demolish those three events’ records in one amazing year.

While racing experts considered Secretariat a model of physical perfection, no one knew at the time that his heart was more than twice the size of twice the size of an average horse’s heart. Dr. Thomas Swerzcek, professor of veterinary science at the University of Kentucky, conducted a post-mortem examination of Secretariat after the stallion died in 1989 at the age of 19. He estimated the heart to weigh an astonishing 22 pounds.

According to Swerzcek, the heart was normal in all aspects and not pathologically enlarged. Penny Chenery, who owned and raced Secretariat, called it “a bigger power pack,” according to Leeanne Meadows Ladin, co-author of Secretariat’s Meadow – The Land, The Family, The Legend. “The large heart undoubtedly contributed to Secretariat’s incredible speed and stamina,” Ladin said, “and now there’s even more research to prove it.”

Marianna Haun, author of The X Factor – Solving the Mystery of Secretariat’s Heart, has studied the large heart phenomenon in racehorses for more than 20 years. “Her research shows that the large heart is passed on the X chromosome from the broodmare,” Ladin said. “So Secretariat got it from his mother, Somethingroyal, who got it from her sire, Princequillo, a great champion of his time.”

Haun, a pedigree expert, even traced the large heart three centuries back to the Darley Arabian, one of the three foundation sires of the Thoroughbred horse. “Haun discovered that racehorses with the Darley heart also have another advantage,” Ladin said. “They have a shorter back with five lumbar vertebrae instead of the typical six. Haun states that this skeletal structure enables a horse to achieve an enormous stride.”

Secretariat’s racing stride was 25 feet, second only to Man O’ War’s stride of 28 feet.

Ladin, who gives tours of Secretariat’s birthplace at The Meadow Event Park in Caroline County, noted that Christopher T. Chenery, founder of Meadow Stable, created what was called “an empire built on broodmares.” His foundation mares produced many champions and helped establish a racing dynasty.

“Mr. Chenery could not have known about the X factor,” Ladin said. “But it was said he had a good eye for a mare. In the case of Secretariat, that proved to be quite visionary.”