Todd Pletcher (left) and Mike Repole explain the scratch of Uncle Mo.

Todd Pletcher (left) and Mike Repole explain the scratch of Uncle Mo.

Mathea Kelley

Uncle Mo Scratched Out of Kentucky Derby

Uncle Mo has been scratched out of the May 7 Kentucky Derby Presented by Yum! Brands.

Juvenile champion Uncle Mo , the second choice on the morning line, was officially scratched out of the May 7 Kentucky Derby Presented by Yum! Brands (gr. I).

The scratch came after days of speculation about the status of the son of Indian Charlie. He had been treated for a gastrointestinal tract infection that was diagnosed after a third-place finish in the April 9 Resorts World New York Casino Wood Memorial Stakes (gr. I), his first career loss.

Trainer Todd Pletcher and owner Mike Repole held a press conference at Churchill Downs at 9 a.m. EDT on  to announce the decision. Despite having a top team of veterinarians who have examined the horse since he arrived in Louisville last week, nobody has been able to diagnose Uncle Mo’s specific illness.

Repole said that he officially made the decision not to run him in the Derby a day earlier after Pletcher told him he did not feel comfortable about the colt's health. What that health problem is remains a mystery for now.

“It’s very frustrating,” Pletcher said. “I don’t know what (the problem) is, and the best veterinarians in the world don’t know what it is.

"It's very, very, very, very, very disappointing. I said last year, honestly, I don’t think I’ve ever had a horse as good as Uncle Mo. To not make it here is a big letdown. I take it as a personal failure, I feel extremely bad for Mike. He’s given us every resource possible to try and get this thing corrected. We ran out of time."

Pletcher said the main physical symptoms that Uncle Mo has shown during the past week are depressed appetite, loss of weight, and a coat that has been off, but the root cause of those issues are not yet known. When pressed on specifics of the bizarre illness, Pletcher cited an enzyme that showed elevation during blood work samples. But doctors have not yet been able to diagnose the problem.

“We’re dealing with an internal issue that we’re not quite sure what it is,” Pletcher said. “He definitely had a GI tract infection, but what we’re trying to figure out (is) if that was the primary issue, a secondary issue, or the function of something else.

“We have one specific enzyme that is elevated and they cannot identify why. Generally, without getting too scientific, when this particular enzyme is elevated, there is something else in the blood work that would lead them toward the direction of a liver or a kidney, or something else. But in this has everyone baffled. The only thing I can tell you now is that nobody knows what it is.”

One of the most perplexing aspects of the situation is that Uncle Mo is apparently physically sound and has galloped well when he has been on the track in the mornings. In fact, he went out at 6:15 on Friday morning, going about 1 1/2 miles over the main track. Pletcher said he “galloped like a monster.”

Pletcher stopped short of saying that Uncle Mo would be taken out of training, but it seems unlikely that he would remain in training given the uncertainty of his situation. He is to stay in Kentucky for the short term while the connections decide what to do, but will likely be sent to a clinic at some point for further evaluation. Pletcher said he would eventually be flown to New York. There is no target date for his return to racing and a start in the other two Triple Crown races seems unlikely at this point.

"Sometimes you can deal with issues when you know what they are, you know what’s okay and what’s not okay. But when you don’t know, that’s when you get scared," Pletcher said.

Repole said the three veterinarians treating Uncle Mo had not recommended that Uncle Mo not run, but that Pletcher made the final decision not to put the horse in the 1 1/4-mile Derby considering the questions about his health.

There have been rumors all week that Uncle Mo would not run in the Derby, even though he was entered for the May 4 post position draw. Pletcher said the colt improved while undergoing treatment but that he regressed when vets began to withdraw medications over the past two days.

Because of the tenuous circumstances around his health—not knowing the exact cause of his illness and the fact that he has trained well—Repole and Pletcher were still somewhat optimistic that Uncle Mo could make it to the starting gate on May 7. But late on Thursday they decided it was not worth the risk.

Pletcher defended their decision to enter Uncle Mo, which kept Sway Away out of the race.

Repole and Pletcher will still be represented in the Derby by Stay Thirsty . Ramon Dominguez will keep the mount.

"Does it hurt that he’s not here?" Repole said. "Yes, because Uncle Mo, in my opinion he’s five to seven lengths better than any horse in this race."

"As bad as I want win this race, (Pletcher) is 43 and I’m 42. He looks a lot older than I do, but the bottom line is that we’re going to be around a while. I have 100 friends and family in town and we still have a chance. Stay Thirsty had the best work of his life the other day. How many people have a horse scratched from this race and still have another one?”

The defection of Uncle Mo meant that three years in a row that one of the favorites for the Derby was withdrawn prior to the race. Two years ago, I Want Revenge , the morning-line favorite, was scratched on the day of the race after a filling was discovered in an ankle.

Last year, early Derby favorite Eskendereya was withdrawn from the Kentucky Derby six days before the race after a filling was discovered in his left front leg. Each of the three horses were Derby mounts for jockey John Velazquez, who has has picked up the mount on Animal Kingdom. Robby Albarado who had the call on Animal Kingdom, was injured in a fall May 4. Albarado suffered a broken nose and a laceration above his eye that required stitches due to his horse stepping on him.

Pletcher, who trained Eskendereya, went on to get his first Derby win last year with Super Saver .