Nineteen Thoroughbred racehorses suffered fatal hind-leg injuries on synthetic racetracks in California in 2008, compared with one fatal hind-leg injury on a dirt racing surface in the state in the same year, according to data presented to the California Horse Racing Board on Thursday.\nThe data suggests that horses are suffering hind-leg injuries at a greater rate on synthetic surfaces when compared to hind-leg injury rates on dirt tracks. According to the data, there were 111 fatal breakdowns on synthetic surfaces in 2008, and 19 were as a result of hind-leg injuries, or 17.1 percent. In contrast, there were 65 fatal injuries on dirt surfaces in 2008, and only one was as a result of a hind-leg injury, or 1.5 percent.\nThe results are sure to invigorate critics of artificial racing surfaces, which were mandated for all major California Thoroughbred tracks beginning in 2006 because of expectations that the surfaces would reduce fatal injuries. Since the tracks were installed, many horsemen have complained that their horses are suffering higher rates of hind-leg and soft-tissue injuries.\nDr. Rick Arthur, the equine medical director of the CHRB, cautioned that the data was not that far out of line from historical data showing that horses suffer fatal injuries in the hind end in about 15 percent of catastrophic breakdowns, regardless of surfaces. However, Arthur also said that the data was beginning to demonstrate a "disproportionate" number of hind-end injuries as a result of racing and training over synthetic tracks.\n"There does appear to be a greater incidence of injuries in the back end," Arthur said. "That's consistent with what the veterinarians and the trainers have been telling us, and this is the first time that we have documentation of that."\nArthur said that the data also pointed to a lower incidence of front-leg injuries on synthetic tracks compared to dirt tracks, but he also said that he did not believe the data on the rate of front-leg injuries was "conclusive."\nThe data presented to the board Thursday is expected to be part of an overall injury report that will be completed next month, according to board spokesman Mike Marten. The data was presented by Hailu Kinde, interim director of California's necropsy program, which collects information on all horses that die at a racetrack or training facility in the state.\nAccording to the data, 351 horses died at racetracks or training facilities in 2008. Of that total, 258 were Thoroughbreds. Also from the 351 total, 163 deaths were as a result of racing injuries, 93 were the result of training injuries, and 95 were as a result of heart attacks, founder, or other, non-exercise related incidents.