LOUISVILLE, Ky. — Churchill Downs will invest $8 million for an on-site equine medical center as part of several other measures to improve safety for horses and riders.

The medical center is expected to open next March and will include a quarantine facility. Next month’s Kentucky Derby will have a temporary medical center. The track’s parent company, Churchill Downs Incorporated, will also hire an equine medical director to oversee safety at its facilities.

The historic track will also install camera surveillance with other improvements to the backside area.

Earlier Thursday, Churchill Downs and several other tracks announced they would phase out use of the anti-bleeding medication Lasix for horses within 24 hours of racing. The track later announced other initiatives, including advocating for additional equine medication reforms; the formation of an Office of Racing Integrity that will to develop uniformed medication and safety standards; formalizing concussion protocol for jockey safety; and adopting international standards for riding crop use.

ARCADIA, Calif. — Santa Anita will continue racing through the end of the current meet on June 23, despite objections from animal rights activists who urged the California Horse Racing Board to shutter the historic track.

Chairman Chuck Winner said at the racing board’s monthly meeting Thursday that he sees no reason to reallocate any of Santa Anita’s dates to another track.

Since the Arcadia track reopened March 29, one horse died during a turf race. Overall, 23 horses have died in training or racing incidents since Dec. 26.

Eleven of 20 people who addressed the board during a public comment period identified themselves as animal rights activists, with several quoting statistics about horse deaths from the same website. Some called for a ballot measure next year that would ask California voters to decide on the future of horse racing in the state.

ARCADIA, Calif. — All three sites of the Triple Crown are among several major tracks that have agreed to phase out the use of a common anti-bleeding medication starting next year.

Starting in 2020, 2-year-old horses won’t be allowed to be treated with the drug Lasix within 24 hours of racing. Lasix is a diuretic given to a majority of horses on race days to prevent pulmonary bleeding.

In 2021, the same prohibition would extend to all horses running in any stakes race at tracks in the coalition that announced the ban Thursday. That’s the year the Triple Crown would be run for the first time under the new medication rules. Churchill Downs, Pimlico and Belmont are the hosts for the Triple Crown races: Kentucky Derby, Preakness and Belmont.

While many American trainers say Lasix is a vital medication that keeps horses safe, animal-rights activists say it amounts to a performance-enhancing drug and note most tracks in the world do fine without it. Outside North America, most racing countries ban race-day medication.

The Breeders’ Cup, which is thoroughbred racing’s world championships, is part of the coalition announced Thursday. This year’s event is set to be run at Santa Anita in November.

Other major tracks participating are Aqueduct and Saratoga in New York, California’s Del Mar and Los Alamitos, Gulfstream and Tampa Bay Downs in Florida, Arlington International outside Chicago, Keeneland in Kentucky, Lone Star in Texas, Fair Grounds in Louisiana, Remington in Oklahoma and Oaklawn in Arkansas.

Other tracks involved are Laurel in Maryland and Presque Isle Downs in Pennsylvania.

Santa Anita in Southern California and Golden Gate Fields in Northern California will continue to run under recently announced limits to race-day medication that were prompted by the deaths of 23 horses since Dec. 26 at Santa Anita. Both California tracks are owned by The Stronach Group.

“It took 23 dead horses on one track, but we were sure that the racing industry could change if it wanted to and phasing out Lasix for stakes races and 2-year-olds is an excellent first step in what must be an ongoing overhaul of racing rules nationwide,” Kathy Guillermo, senior vice president of People for the Ethical Treatment of Animals, said in a statement.

The tracks will need to work with trainers and racing commissions in each jurisdiction to implement the plan.

“This is a huge moment that signals a collective move to evolve this legacy sport,” said Belinda Stronach, chairman and president of The Stronach Group, whose holdings include Santa Anita, Gulfstream and Pimlico. “While there is still more work to be done, these reforms are a good start.”

New York Racing Association president and CEO David O’Rourke called it “a progressive and unified approach” to race-day medication.

Churchill Downs Inc. CEO Bill Carstanjen said, “This is a significant and meaningful step to further harmonize American racing with international standards.”

PETA is urging a ban on Lasix for all races, in addition to banning all medications in the two weeks before a race, banning trainers with multiple medication violations, mandating complete public transparency of injury and medication records, ending the use of whips, and switching to high-quality synthetic tracks.

California previously experimented with synthetic surfaces at its major tracks, spending $40 million to install them before eventually returning to dirt.