Champion Zenyatta's weanling filly by War Front was euthanized Tuesday evening after a paddock accident at Lane's End Farm, Team Zenyatta announced on its website.
Nicknamed "Z Princess," the filly was the third foal out of the 2010 Horse of the Year.
"We are deeply saddened to report the passing of Zenyatta's filly," Team Zenyatta posted. "She was a member of our family and had just begun to make her mark on the world. This is a heartbreaking loss for those who knew and loved her."
The filly was euthanized at Rood and Riddle Equine Hospital in Lexington after the paddock accident on the farm.
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Zenyatta has resided at Lane's End since her retirement after the 2010 season. Trained by John Shirreffs for Jerry and Ann Moss, Zenyatta transcended the sport of Thoroughbred racing with her streak of 19 straight victories, her only career defeat coming at the hands of Blame in the 2010 Breeders' Cup Classic.
Zenyatta won the 2009 Breeders' Cup Classic at Santa Anita Park and captured the 2008 Breeders' Cup Distaff, retiring with 13 Grade I victories. Her first foal, a 2-year-old dark bay colt by Bernardini named Cozmic One, is in training with Shirreffs.
Zenyatta also has a yearling colt by Tapit named Ziconic, foaled in April 2013.
"As caretakers of these Thoroughbreds, we collectively mourn the loss of this beautiful filly," Mike Cline, general manager of Lane's End, said in a news release. "On behalf of the Farish family and the entire staff at Lane's End Farm, our condolences go out to Jerry and Ann, Team Zenyatta and all the great fans who support Zenyatta."
Team Zenyatta asked that all messages of love and condolence be sent to the Zenyatta office.
Silver Charm headed to Old Friends
Kentucky Derby champion Silver Charm has been retired from breeding in Japan and will return to the United States per an understanding that was reached at the time he was acquired by the Japan Bloodhorse Breeders' Association.
Silver Charm will reside at Old Friends, a retirement home for racehorses outside Georgetown.
The Robert B. Lewis family, which campaigned the horse to winnings of $6,944,369, will pay for the horse's flight from Japan to the United States.
"We thought the best thing for a horse of his stature was to let him live out his retirement years at Old Friends, a place that will provide him the opportunity to receive his many fans," said Case Clay, president of Three Chimneys Farm.
Three Chimneys will make a donation to Old Friends.
"Everyone at Old Friends is overjoyed," said President Michael Blowen. "He's my favorite horse of all time."
In additon to his 1997 Kentucky Derby victory, Silver Charm also won that year's Preakness Stakes before losing the third jewel of the Triple Crown, the Belmont Stakes, by a half-length to Touch Gold.
He initially stood at Three Chimneys before his move to Japan.