LOS ANGELES _ It was shortly after the sun came up Thursday morning when machinery moved onto the dirt surface at Santa Anita to harrow the racetrack, breaking up dirt clods and giving the wet surface some room to breathe and dry out.
At about 8 a.m., a white panel truck with Biologically Applied Engineering etched in green, eased on to the course, ready to take the next step in what may ultimately decide the near future of Santa Anita Park.
The tool, which race officials hope will help solve the mystery of 21 horse deaths since Dec. 26, was an Orono Biomechnical Surface tester. The apparatus simulates how a horse's foreleg interacts with the dirt surface. Measurements were taken about every 16th of a mile and have been sent for testing.
The track, which has been shut down for training and racing since Tuesday, was a picture of solitude except for a couple of television news trucks. The trainers were back in their barns instead of watching their horses train, as they do most every morning.
It's expected that the training track will be open on Friday. The surface, which is on the inside of the grass course next to the video boards, has a much softer, forgiving base and has had no breakdowns.
It's important to get the horses out of the barn area for exercise beyond walking the shed row, which they've been restricted to since the track closed. Some trainers have decided to take their horses on the roads in and around the barn area, but doing it under tack, with equipment and a rider aboard.
The paddock was open for schooling at 10 a.m., where horses simulate the pre-race ritual of walking to and from the paddock and around the walking ring, but only one horse was spotted there in the first 20 minutes.
Horses are creatures of routine, and their routine has been seriously disrupted.
"They are used to the same thing all the time," said Jim Cassidy, president of the California Thoroughbred Trainers. "They are accustomed to certain ways of doing things.
"If they open this up on Friday, you'll see a lot of the fillies tie up _ they'll get tight in the muscles and they'll get real short because of nerves and the fact they haven't done anything in a few days. You might see an odd case of colic here and there. If these things occur, the reason is because it's been closed."
Dr. Rick Arthur, as chief equine veterinarian for the California Horse Racing Board and University of California, Davis, has been studying the breakdowns since it first became apparent at the beginning of the year that numbers were up at Santa Anita. He said this week that he had not found any evidence that points to a particular type of horse or race or condition posing more risk than others.
Arthur has also been searching for something in the physiology of the horses, through necropsies _ the equine version of an autopsy. He's found no trend so far.
There will be no racing at Santa Anita at least through this weekend, forcing the postponement of the San Felipe Stakes, an important Kentucky Derby prep race, and the Santa Anita Handicap, a lucrative race for older horses. Both had been scheduled for Saturday.
Some horses have been moved to Los Alamitos Race Track in Cypress to train.
