Churchill Downs, home of the Kentucky Derby, says it is "troubled" by the recent spate of horse deaths after racetrack officials on Saturday announced two more horses were put down.
The euthanizations of Lost in Limbo on Friday and Kimberley Dream on Saturday at the track mean a dozen horses have died at Churchill Downs in the past two months.
Kimberley Dream suffered a "significant injury" to her left front leg in Saturday's first race, according to the company that owns the track.
A similar injury impacted Lost in Limbo during Friday's seventh race, and veterinarians deemed the injuries "inoperable and unrecoverable" in both cases, Churchill Downs Inc. said in a news release.
The 12 horse deaths have occurred since the track's stable area reopened for training on March 30, the release stated.
The company said it reported the "highly unusual statistic" with "absolute dismay and sorrow."
"We do not accept this as suitable or tolerable and share the frustrations of the public, and in some cases, the questions to which we do not yet have answers," according to the release.
Churchill Downs said it is working with the Kentucky Horse Racing Commission and the Horseracing Integrity and Safety Authority to investigate the deaths and improve the sport's safety.
Churchill Downs also said it is involved with an epidemiological study with the Jockey Club, the breed registry for thoroughbreds in the US, Canada and Puerto Rico, "to review each individual horse to determine if there are any undetected patterns that have not been previously identified."
Company officials say they have yet to find a "conclusive discernable pattern" as they await findings of investigations into the horses' injuries and deaths.