Dulcify was foaled in New Zealand and had a good pedigree as he was sired by the Irish 2000 Guineas winner Decies out of Todman mare Sweet Candy, but because he was plain-looking with a parrot-mouth he was gelded early and spelled. He went on to win 10 of his 21 starts over a 14 month period in a brilliant racing career with the most tragic of endings.
Raced by Allan Maller and Bill Rigg, trainer Colin Hayes said he was the greatest horse he ever trained.
His first race was as a three-year-old in 1978 where he made an immediate impression by winning at Morphettville at odds of 300-1. Next he ran second in the SAJC Derby. There followed a brilliant season where he won the Victoria Derby, the AJC Derby, the STC Rosehill Guineas, and the VRC Australian Cup where he defeated reigning champions of the turf Manikato and Family of Man.
In 1979 as a four-year-old he won the Craiglee Stakes and Turnbull Stakes, then defeated a particularly strong field in the W.S. Cox Plate by a massive 7 lengths . A week later he also took out the Mackinnon Stakes. then was sent out 3-1 favourite in the 1979 Melbourne Cup. During the race he was galloped on and fractured his pelvis and had to be put down. The crowd was stunned and many left in tears in what was regarded as the saddest Melbourne Cup.
He was inducted into the Australian Racing Hall of Fame in 2014.