Shayne, 51, World's Oldest Horse? (PHOTO)

At the wise age of 51, Shayne is believed to be the world's oldest horse.

The liver chestnut-Irish Draught cross lives at the Remus Memorial Horse Sanctuary in Essex, where he enjoys spa-like treatments, daily walks and high-calorie meals, the Sun reports.

A few grey hairs and a mild case of arthritis are all that hint at Shayne's old age. Otherwise, the horse is in great condition.

"We like to think the secret of our success is in allowing the animals to relax and to ask nothing of them," Burton told NBC's "Today."

Shayne's owners haven't registered the title of "world's oldest living horse" with officials, but a spokesperson for Guinness World Records says they haven't received a claim for the title since Badger, another 51-year-old horse, died in 2004, according to the Sun.

The horse also happens to live in the same town as Pip, unofficially the world's oldest dog.

Back in the United States, a horse named Mr. Kid Bars was dubbed the oldest horse in Missouri in 2009.

The animal, which was 40 at the time, was blind in one eye and had difficulty hearing, but had a successful past as a champion barrel racer, the Columbia Missourian reports. Kid also worked as a therapy horse at a local center.

Much like Shayne's caretakers, Kid's owners stressed that TLC and a healthy diet are the secrets to longevity.

"He might be the smartest horse in Missouri, if they have such a contest. There is no doubt about that," Karen Grindler, director of the Cedar Creek Therapeutic Riding Center, told the Missourian in 2009.