Royal Mo suffered a career-ending sesamoid fracture to his right front ankle on Sunday morning at Pimlico Race Course during a workout that was to be his last drill for the Preakness Stakes on Saturday, trainer John Shirreffs said.
Shirreffs said Royal Mo had fractured the inside sesamoid in that ankle.
"The one positive side is there wasn't any other damage to that leg, he doesn't have a condylar or any other ligaments that were injured, just the right sesamoid," said Shirreffs, who also said Royal Mo was being transported to New Bolton Center in Pennsylvania, the facility best known for treating 2006 Kentucky Derby winner Barbaro after he fractured a hind leg in the 2006 Preakness.
"I don't think they'll operate. I think they'll monitor it and see what it looks like," said Shirreffs, who called the developments "devastating."
"This is absolutely a career-ending injury. He is done as a racehorse," said the Maryland Veterinary Group's Dr. Dan Dreyfuss, who attended to Royal Mo at Pimlico. "If there are no complications, from a life standpoint he should be okay."
Gary Stevens, the Hall of Fame jockey, had flown in to Baltimore and was aboard for the work.
"He won't run again, but he'll make a good daddy," Stevens, reached by telephone, said.
Stevens was working Royal Mo five furlongs in company when the incident happened near the quarter pole on an off track.
"Luckily I had a stranglehold on him. He was just rattling off twelves. He was going to go in a minute," Stevens said. "I was thinking about how much I was going to let him gallop out. And then I heard a loud pop. I was hoping he had just overreached, but that wasn't it.
"He was relishing the track. The track had a good bottom. The track had nothing to do with it. He was on cruise control."
Stevens said Royal Mo had ankle wraps on his ankles and that those bandages, affixed by the groom, helped prevent further damage.
Stevens immediately hopped off Royal Mo and helped support the injured leg until first Shirreffs and then Dreyfuss arrived.
"Gary Stevens was holding up the leg and Mr. Shirreffs was there helping as well. The leg did not spend much time on the ground after they got him pulled up, which is really important," Dreyfuss said.
Dreyfuss said he tranquilized Royal Mo and then affixed a Kimzey splint to the injured limb to provide support.
"He tolerated that incredibly well, he's a first-class patient," Dreyfuss said. "We were able to walk him onto the horse ambulance, brought him back to the stakes barn, took radiographs through the Kimzey and at that point saw the comminuted fracture."
There are two sesamoid bones in each ankle. Dreyfuss said the other sesamoid in the injured ankle was "intact and in its normal anatomic position, which generally means that the soft tissues around it were not severely damaged."
Dreyfuss said after talking to Shirreffs, arrangements were made to transport Royal Mo to New Bolton, where, Dreyfuss said, "they can do more diagnostics if necessary and they're available 24 hours a day to monitor the colt's comfort."
Royal Mo most recently finished third in the Grade 1 Santa Anita Derby. He was entered in the Kentucky Derby, but was ranked 21st on points and earnings and was put on the also-eligible list, from which he did not draw-in to the 20-horse field.
On Tuesday, Royal Mo and Always Dreaming, the Kentucky Derby winner, were flown to Baltimore.
Royal Mo, a large, gorgeous colt by Uncle Mo, was purchased as a yearling by owners Jerry and Ann Moss for $300,000. He raced six times, winning twice, including the Grade 3 Robert Lewis Stakes at Santa Anita in February. He was ninth in the Grade 2 Rebel Stakes at Oaklawn and third in the Santa Anita Derby in his other stakes tries. He earned $267,200.
The loss of Royal Mo brings the expected Preakness field to 10. Entries are due Wednesday morning, and posts will be drawn early Wednesday evening.
Two of the outsiders for the Preakness, Multiplier and Senior Investment, both worked five furlongs at Keeneland on Sunday. Multiplier was timed in 1:00.80, Senior Investment in 1:02. Both are scheduled to arrive at Pimlico on Tuesday.
Classic Empire, fourth in the Derby, was due to arrive at Pimlico on Sunday afternoon.
--additional reporting by David Grening