Lawyer Ron was among the Kentucky Derby favorites in 2006 and a champion older horse in 2007. When he was retired from racing last year, he had earned nearly $2.8 million.
The 6-year-old horse was euthanized Friday night because of complications from colic surgery, Stonewall Farm Stallions said on its Web site.
"Not only was he a superior racehorse horse but his physical presence and contagious personality captivated everyone that saw him," Stonewall manager Clark Shepherd said.
Lawyer Ron won 12 of 26 races. He was standing his second season at stud at Stonewall and his first crop of foals arrived this year.
"His first foals are tremendous," Shepherd said. "When breeders call in to report their Lawyer Ron foals being born, they all have a story to tell. This is obviously a huge loss for us, as well as for the racing and breeding community."
Lawyer Ron came into the 2006 Derby having won all seven of his starts on dirt tracks, but ran 12th behind Barbaro. After an interest in the horse was purchased by Stonewall Farm of Midway, Ky., the colt was transferred from trainer Bob Holthus to Todd Pletcher.
Lawyer Ron's Eclipse Award-winning 4-year-old season included victories in the Oaklawn Handicap at Oaklawn Park, the Whitney Handicap in track-record time and the Woodward Stakes, both at Saratoga, and a narrow loss to future two-time Horse of the Year Curlin in the Jockey Club Gold Cup at Belmont.
As a 3-year-old, Lawyer Ron won the Risen Star at the Fair Grounds and the Southwest, the Rebel and the Arkansas Derby at Oaklawn before the 2006 Kentucky Derby.
The colt was bred and owned by James T. Hines, Jr., who died a few months before the race at Churchill Downs that year. Lawyer Ron was then managed by Hines' lawyer, Ron Bamberger, for whom the horse was named.
A few days before the Derby, Stonewall Farm purchased an interest in the colt, who was then moved from Holthus' stable at Oaklawn to Pletcher's New York stable.