Unbridled's Song, the son of 1990 Kentucky Derby winner Unbridled who went on to capture a Breeders' Cup race and become a prolific sire, died Friday. He was 20.
Taylor Made Stallions, where the horse stood his entire career, said in a statement a large and inoperable mass was discovered in his sinus cavities and around the optic nerves. The horse began showing acute neurological symptoms Thursday and was euthanized.
''Unbridled's Song was one of those great horses,'' Taylor Made president and CEO Duncan Taylor said. ''He had it all — looks, pedigree, speed, and presence. Our team loved him from the beginning.''
Unbridled's Song sired 730 winners from more than 1,000 starters, the farm said.
As a 2-year-old, Unbridled's Song won the Breeders' Cup Juvenile. The next year, he won the Florida Derby and Wood Memorial. He was the 7-2 favorite in the 1996 Kentucky Derby but finished fifth while another Unbridled colt, Grindstone, was first.
Unbridled's Song earned $1,311,800 before retiring to stud in 1997.
Taylor Made said Unbridled's Song's $298,118 lifetime yearling average is best among all North American sires and third all-time in North America among sires by gross yearling sales with $198,844,653 in gross sales.
He sired 100 stakes winners, including 45 graded stakes winners and 15 Grade 1 winners, and at least one Grade 1 winner for 12 consecutive years.
Unbridled's Song also has three Breeders' Cup winners: 2010 Ladies' Classic winner Unrivaled Belle, 2001 Distaff winner Unbridled Elaine and 2008 Juvenile winner Midshipman, the Eclipse champion 2-year-old colt that year.