66 inches

The King of Horses:

Secretariat (March 30, 1970 – October 4, 1989) was an American Thoroughbred racehorse that in 1973 became the first U.S. Triple Crown winner in 25 years. He set race records in all three events in the series – the Kentucky Derby (1:59 2/5), the Preakness Stakes (1:53), and the Belmont Stakes (2:24) – records that still stand today. He is considered to be one of the greatest Thoroughbreds of all time. In 1999, ESPN ranked Secretariat the 35th best athlete of the 20th century, the highest ranking racehorse on the list.

Secretariat was sired by Bold Ruler out of Somethingroyal, by Princequillo. He was foaled at The Meadow in Caroline CountyVirginia. Like his famous predecessor Man o’ War, Secretariat was a large chestnut colt and was given the same nickname, “Big Red.” Secretariat’s grandsire, Nasrullah, is also the great-great-grandsire of 1977 Triple Crown winner Seattle Slew.

Secretariat stood approximately 16.2 hands (66 inches, 168 cm) tall and weighed 1,175 pounds (533 kg), with a 75-inch girth, in his racing prime.

In the fall of 1989, Secretariat was afflicted with laminitis—a painful and often incurable hoof condition. When his condition failed to improve after a month of treatment, he was euthanized on October 4 at the age of 19. Secretariat was buried at Claiborne Farm in Paris, Kentucky, given the rare honor of being buried whole (usually only the head, heart, and hooves of a winning race horse are buried, and the rest of the body is cremated).

It was estimated Secretariat’s heart probably weighed 22 pounds (10.0 kg), or about two-and-three-quarters times as large as that of the average horse.