A celebratory bowl of grated carrots sounds like a disappointing way to mark your birthday, but Subzero wouldn't have it any other way.

The Melbourne Cup-winning grey turned community education ambassador is 28-years-old on Monday.

It's a birthday he shares with all horses in the southern hemisphere so their ages can be standardised for breeding and racing.

His northern hemisphere counterparts blow out the candles on January 1 in accordance with their season.

Subzero's owner Graham Salisbury says his birthday present this year will be a big bowl of carrots and maybe a beer.

"He loves a drink," Salisbury told AAP.

"He used to have a can but they were too light when he'd finished with them and he was crushing them in his teeth. But he can handle a stubby."

Salisbury first laid eyes on Subbie, as he's affectionately known, when champion trainer Lee Freedman brought the grey son of Kala Dancer to the Flemington stables as a yearling.

"I said to Lee, `Gee he's a nice horse. Keep me in mind, will you, and I can use him as a clerk of the course horse,'" Salisbury said.

When Subzero won the 1992 Melbourne Cup after winning the Adelaide Cup and South Australian Derby earlier that year, Salisbury didn't like his chances of snapping up the famous grey.

But to his surprise, Subzero's owners offered Salisbury their $2 million champion when he retired from racing as a four-year-old.

"I got him in 1994 and he's been part of the family ever since," Salisbury said.

The pair worked together as clerk of the course at Flemington for 15 years.

After retiring from the track, Subbie has taken up post as a racing ambassador where he visits more than 100 schools, 35 retirement villages and 30 different charities each year.

While he might be getting a bit long in the tooth, it doesn't look like Subbie will slow down any time soon.

"I keep him ticking over. I don't ride him anymore but he's kept pretty busy" Salisbury said.

"It's not strenuous and he's not overtaxing himself, but it keeps his muscle and it keeps him alert in himself."

"He's still got his nice, round rump and he carries his condition right."