Uncle Mo will not run in Saturday's Kentucky Derby. Uncle Mo galloped Friday morning at Churchill Downs in Louisville, Ky., without his Derby saddle towel. The announcement was later made at the track.
Uncle Mo's owner, Mike Repole, was not present during the morning workout.
The sleek bay colt has been recovering from a stomach ailment but has looked good as he galloped in recent days.
Last year's juvenile champion, Uncle Mo had been the 9-2 second choice behind 4-1 early favorite Dialed In.
On Thursday, Repole was awaiting results from the latest vet exam.
"If he's not what we deem to be 100 percent tomorrow, he's not going to be 100 percent on Saturday," he said.
Repole said Thursday he wouldn't sacrifice Uncle Mo's health to satisfy his 30-year dream of having a horse in America's greatest race. He still has Stay Thirsty in the field.
Uncle Mo won last year's Breeders' Cup Juvenile at Churchill and had taken a perfect record into the Wood Memorial.
There, Uncle Mo led the field with a quarter-mile to go, but two horses passed him and he finished third by a length. Afterward, Uncle Mo's appetite fell off and raised suspicions. An exam turned up the gastrointestinal tract infection.
Trainer Todd Pletcher wasn't talking Thursday. But he's said Uncle Mo responded well to treatment and his appetite had returned.
"We got to listen to what Uncle Mo is telling us," Repole said, "and he's telling us he's getting better. He's telling us he's progressing.
"If the three vets say, 'yes' and Todd says,'no,' the answer is 'no,'" Repole said.
It's still possible Uncle Mo could turn up in the Preakness on May 21. If not, Repole said he'll wait until Saratoga in July.
"I want this horse to be the best horse in the country and not just for me, but for racing," he said.
Information from ESPN's Jeannine Edwards and The Associated Press was used in this report.
