Chriselliam, winner of the Breeders' Cup Juvenile Fillies Turf and a finalist for an Eclipse Award, was euthanized Feb. 7 in Newmarket, England, as a result of a foot infection, according to Racing Post.
The Post reported Europe's champion 2-year-old filly was being treated for a poisoned off hind foot for a couple of weeks and reports last month indicated that the infection was under control.
The filly was sent to Newmarket Equine Hospital Feb. 5.
"She went up for surgery earlier today and they found the infection had spread and she had to be put down," trainer Charles Hill told the newspaper Feb. 7. "It was progressing into the pedal bone. She has had the problem for a month and during that time every effort has been made to resolve it but unfortunately it was uncontrollable. The vets were unable to get the infection under control with the antibiotics."
An Irish-bred daughter of Iffraaj, Chriselliam was co-owned by retired British champion jockey Willie Carson, Emily Asprey, and Christopher Wright.
Bred by Ballylinch Stud, Chriselliam was the favorite for this year's Qipco One Thousand Guineas on May 4. The 3-year-old filly had three wins and a second from six starts last season and earnings of $729,684.
In addition to the Breeders' Cup victory that resulted in consideration for champion 2-year-old filly honors in the U.S., Chriselliam won the Shadwell Fillies Mile at Newmarket.