Trying to pinpoint which horse can claim the record of oldest is a bit tricky. On average, ponies outlive larger breeds so most claims of oldest are ponies in their fifties or sixties. On my blog post How Long Do Horses Live many readers left comments about horses they knew were in their late thirties and even early forties or fifties. How old is the oldest horse is a very common question and one of the most commonly asked questions searched for on this site. It can be difficult to verify claims of age, especially with unregistered horses, or those whose paperwork may have been lost when they were bought and sold. An article written by Dr. Bob Wright, who was a veterinary scientist specializing in horses for the Ontario Ministry of Food and Agriculture lists a 66 year old pony from Wales, a 54 year old pony stallion from France, a draft horse who lived to be 52 and a mare from Missouri who was 53.
The Belfast Telegraph reports that 54 year old donkey named Rosie may be the oldest of her kind. Ted E. Bear is commonly cited as the oldest pony in the US, living to age 55. Back in March of 2006 I blogged about Jesse, a pony from Ireland who was 49. The original article about Jesse has since been removed from the Belfast Telegraph archives.
Guinness World Records
The Guinness Book of World Records is often cited as listing "Old Billy" a barge horse to be the record holder for the oldest horse at age 62, although I could not find the record on their website. The Guinness Book did record the oldest equine twins alive in 2007 were born in 1982 making them 25 years old at the time. This is significant because twin equines rarely survive much past birth. In 2007 Horse and Hound reported the demise of Sugar Puff, a 56 year old Shetland cross pony who made it into the Guinness Book records.
With our increasing knowledge of equine care and medicine, I have no doubt we will see these records broken in the future. Who knows, maybe you or I will own the world's oldest horse!