There have been six catastrophic breakdowns at Del Mar in the pre-meet training and first six days of live racing. Three occurred during morning training on Polytrack, two happened during races on Polytrack, and one was in a turf race. The fatalities came from six different barns.

Dr. Rick Arthur, the equine medical director for the California Horse Racing Board, said while there are not yet studies to scientifically prove it, breakdowns will often cluster at the beginning of a meet because of a change in racetrack surface. Southern California has three different synthetic main tracks. Del Mar has Polytrack, Santa Anita has Pro-Ride, and Hollywood Park (whose meet closed July 19) has Cushion Track. The Cushion Track this year has been playing more like a traditional dirt surface.

“I hate to be anthropomorphic, but think about if you were jogging on the side of the road and then you started jogging on the sand or the beach,” Arthur said. “Apparently, you are putting different stresses on different structures when you change surfaces.”

Arthur noted that in 2006, the last year Del Mar had a dirt surface, during the first week of the meet there were five racing fatalities on the main track, one on the turf during a race, and one on the turf during training.

“There were three fatalities on the main track for the entire rest of the meet and one on the turf,” Arthur said. “The rest during that time were training fatalities.”

Altogether, Del Mar had 18 fatalities during the 2006 meet, one of the factors that led to the CHRB mandate that major California tracks install synthetic surfaces.

“In the 1980s, the HBPA funded a survey that had good data,” said Arthur. “It showed that the first two weeks of meets were when most fatalities occurred. That was back when the Southern California dirt tracks were very different from each other. The way I interpret the data, horses had to adjust to the new track. That was never confirmed. It is simply a hypothesis.”

Del Mar also historically has a high number of horses working on its track daily during the meeting because the off-site stabling is located 100 miles north at either Santa Anita or Hollywood. Over the opening weekend of July 25-26, 195 horses worked on the main track on Saturday and 204 worked over the surface on Sunday.