Eclipse Award-winning jockey Ramon Dominguez has announced his retirement on doctors' advice because of head injuries sustained in a January fall at Aqueduct.

The 36-year-old New York-based rider said he had hoped to resume his career but doctors advised him to retire after he fractured his skull.

"Riding thoroughbreds has always been my passion and my calling," Dominguez said in a statement. "When I was 13 and watched my first horse race in Venezuela, I knew that I would become a jockey, and my riding career has brought happiness and success beyond what I ever expected."

Dominguez was injured on January 18 when his mount, Convocation, fell and he was thrown to the inner dirt course. After more than two weeks in hospital, he was transferred to a rehabilitation facility.

He rode 4,985 winners from 21,267 career races in North America and was the Eclipse Award winner as the nation's top jockey for the past three years.

Dominguez rode in four Triple Crown races in his career. He finished second in the 2006 Kentucky Derby aboard Bluegrass Cat; second in the 2010 Preakness with First Dude; second in the 2005 Preakness; and third in the 2010 Belmont.

He was never worse than third in 18 career Breeders' Cup races, winning three of them - the Turf in 2004 and 2012 and the 2011 Juvenile.

Dominguez thanked his family, fans and fellow riders for their support since his accident but said he wasn't yet ready to speak publicly as his recovery continued.

New York Racing Association vice president and director of racing P.J. Campo said Dominguez's accomplishments were only part of his story.

"He has epitomised class both on and off the racetrack. Universally respected by his fellow riders and beloved by fans, Ramon has built a towering and well-deserved reputation that serves as a standard for all future jockeys," Campo said.