The racing world is mourning the loss of Uncle Mo, a stallion who left an indelible mark both on the track and in the breeding shed. Owner Mike Repole shared the heartbreaking news that Uncle Mo was euthanized following a left foreleg injury. Despite undergoing surgery in an attempt to save him, the recovery process proved too difficult for the beloved champion.

Repole expressed his profound sadness, calling Uncle Mo much more than a racehorse or an iconic stallion—he was family. "There will never be another horse that makes me feel or will impact my life the way that Uncle Mo has," Repole said. "He was and always will be the patriarch of Repole Stable."

Uncle Mo’s legacy began on the track, where he dazzled fans with his brilliance under the guidance of trainer Todd Pletcher and jockey Johnny Velazquez. His dominance earned him the title of Champion 2-Year-Old Colt in 2010. After retiring to stud, Uncle Mo’s influence only grew, as he sired an impressive list of stars, including Kentucky Derby winner Nyquist.

Repole extended heartfelt thanks to those who were part of Uncle Mo’s journey, from Pletcher’s barn to the Coolmore family and the horse’s devoted groom, Rene. “I am so grateful for the time that Uncle Mo and I spent together this May,” Repole shared, reflecting on cherished memories of his time with the stallion.

Uncle Mo’s impact on the sport is immeasurable, but for Repole, his significance was deeply personal. "Thank you, Uncle Mo, for fulfilling my childhood dreams of owning a special racehorse. I love you, Uncle Mo. Rest in peace."

The Repole Stable, Todd Pletcher’s team, and the Coolmore family are all grieving the loss of a horse who meant so much to so many. Uncle Mo’s memory will forever be etched in the hearts of those who knew and admired him.

Uncle Mo by Indian Charlie - Playa Maya, by Arch

2008, bay, entered stud 2012

Sire of 108 Stakes winners
15 individual Grade 1 winners

Fee: USD 125k (2025) 

Image: Uncle Mo Stallion Photo