A 51-year-old chestnut stallion from Brentwood, Essex, could be the world's oldest horse, the Daily Mail reported Thursday.
Shayne lives in the same town as Pip, the 24-year-old terrier who is thought to be the world's oldest dog.
The elderly nag has been living at the Remus Memorial Horse Sanctuary since 2007, and is still in better shape than many of his stable mates.
He is believed to have inherited the title of the world's oldest living horse after the death of the previous holder in 2004.
He is now enjoying a laid back retirement with four meals a day at the 40-acre sanctuary, founded by Sue Burton, the newspaper added.
Burton said: "Shayne is a really good boy. He is still very active - sometimes we forget how old he is."
"I guess his secret to a long life is taking it easy in his old age and enjoying his retirement."
Shayne was brought to the sanctuary in April 2007 after spending many happy years with his previous owner in Chingford, Essex.
The previous title of oldest living horse in the world was held by Welsh/Arab steed Badger, from Pembrokeshire, Wales, who died aged 51, in 2004.
Shayne does not have a birth certificate but they were given his birth date by his previous owner and have since verified his age with medical checks.