A detailed report to the California Horse Racing Board (CHRB) at its Nov. 21 meeting concluded that the cluster of sudden deaths from famed trainer Bob Baffert's Betfair Hollywood Park barn did not have any similarities to each other and had no single, identifiable cause.

"All of these horses had pathological changes to one degree or another that, frankly, you couldn't do intentionally if you wanted to," said Rick Arthur, DVM, the equine medical director for the CHRB. "I don't even know if you could do it unintentionally."

Arthur and Francisco Uzal, DVM, MS, PhD, of the California Animal Health and Food Safety Laboratory System, which conducts necropsies on racehorses that die on a California racetrack, presented the report to the CHRB during its regular monthly meeting, held at Hollywood Park, in Inglewood, Calif. The 26-page report outlined the findings on seven cases, all of which occurred out of Baffert's Hollywood barn between late 2011 and early 2013.

"There is no factually based explanation as to why these sudden deaths clustered in Baffert's barn at Hollywood Park, and not at any other tracks where Baffert stables, races, and trains horses with similar training and veterinary practices," said Arthur in quoting from the report