Princess Lili B broke both front legs while training. As is common after such injuries to horses, she was euthanized. The 22 deaths since Dec. 26 are more than the total number of deaths, 20 over 122 racing days, in 2017, according to Jockey Club data.

The track has been shut down twice this year and remains suspended for racing.

The track’s policy changes came after a bill, the Horseracing Integrity Act of 2019, was introduced in Congress on Thursday by Representatives Paul Tonko, Democrat of New York, and Andy Barr, Republican of Kentucky. The bill would create a private, independent authority, the Horseracing Anti-Doping and Medication Control Authority, responsible for developing and administering a nationwide antidoping and medication control program for horse racing.

The industry has resisted such changes for decades, and Santa Anita’s spike in fatalities once again put the sport’s lack of meaningful oversight in the spotlight. The Stronach Group, under pressure from animal rights groups as well as horse trainers, apparently had little choice but to take drastic measures to deflect blame.

“We will wait no longer for the industry to come together as one to institute these changes,” the company’s statement said. “Nor will we wait for the legislation required to undertake this paradigm shift. We are taking a stand and fully recognize just how disruptive this might be.”

Kathy Guillermo, a senior vice president for PETA, the animal rights group, said, “This groundbreaking plan will not bring back the 22 horses who have died recently, but it will prevent the deaths of many more and will set a new standard for racing that means less suffering for thoroughbreds.”

With the Kentucky Derby less than eight weeks away, neither animal rights activists nor casual sports fans have the stomach to see a horse be put down after a catastrophic injury. Ever since the Kentucky Derby in 2008, when the filly Eight Belles had to be euthanized after finishing second, racing officials have worried that another high-profile breakdown could put the sport out of business.

In a 2012 series, The New York Times showed that 24 horses died each week at racetracks across America, many of them because of over-medication or a lack of regulatory protection. It prompted meaningful regulations across the United States that led to a decline in the death rate.