Over a similar period in the 2017-18 season, 10 horses died, while eight died in 2016-17 (per NBC News). Some are pointing to the region's unusually wet and cold weather this winter as a possible cause.
"We think that [rain] could definitely contribute even though our experts are telling us not," Tim Ritvo, chief operating officer of The Stronach Group, which owns Santa Anita, told the Associated Press. "The tracks out here are built not for weather like that."
"I think the weather has a lot to do with it," said Ron McAnally, the trainer of the horse euthanized Tuesday. "Santa Anita has been a wonderful track, and they've done all kinds of tests. I don't know what else they could do. It's a fluky thing."
Mick Peterson, an expert from the University of Kentucky who was also enlisted to inspect the track, was not able to discern any irregularities, but he said that he told Santa Anita officials to "keep testing until we know what's going on." Peterson added, "We're all in. We're going to figure it out."
As the death toll has climbed over the past few weeks, Santa Anita has come under heavy criticism from animal rights activists, some of whom have staged protests at the track. After the 20th horse died Saturday, People for the Ethical Treatment of Animals released a statement demanding that the track "close right away" and calling for an investigation into "whether injured horses were being forced to run" while given anti-inflammatory drugs.
"Obviously, one horse is too many," Ritvo said. "The recent rash is just horrible. We need to definitely take a step back and evaluate everything."
In November this year, Santa Anita is set to host the Breeders' Cup, which will mark a record 10th time the event is held at the track in Arcadia, Calif. With roots dating to the 1870s, the original Santa Anita Park opened in 1907 but closed after a few years, then the facility still in use was established in 1934 by a group of investors including movie mogul Hal Roach.
Among the Hollywood celebrities who owned horses that raced there were Spencer Tracy, Errol Flynn, Al Jolson and Bing Crosby, and it served as the site for equestrian events during the 1984 Olympics. Legendary champions such as Affirmed and John Henry strutted their stuff at Santa Anita, as did Seabiscuit, whose 2003 biographical movie was filmed at the track.
By canceling races at least through the coming weekend, Santa Anita has postponed two of its most notable events: the San Felipe Stakes, which features three-year-old Kentucky Derby hopefuls, and the Santa Anita Handicap, contested among older horses. However, trainer Bob Hess asserted that everyone associated with the track "agree it's best" to shut it down and try to solve a tragic, and vexing, issue.
"Without our athletes, without our most precious asset, there is no sport," Hess told the Times. "Something is wrong and needs to be fixed and addressed immediately. It's past the point of embarrassing.
"Santa Anita is the 'Great Race Place' and it's not great. I'm glad we're doing this. Without the horses, we're nothing."
