The fatal breakdown of the filly Eight Belles on Saturday, shortly after she finished second in the Kentucky Derby, has prompted People for the Ethical Treatment of Animals (PETA) to demand the institution of "broad reforms to prevent future tragedies."

PETA, which claims 1.8 million members nationwide, expressed its outrage Sunday to the Kentucky Horse Racing Authority. In a letter to its chairman, Robert M. Beck, PETA president and founder Ingrid E. Newkirk advocated immediate and radical changes:

• Not allowing thoroughbreds to begin training until age 3, at the earliest.

• Having all races in Kentucky run on synthetic surfaces or on grass. (Keeneland and Turfway Park have switched to Polytrack; Churchill Downs and Ellis Park use conventional dirt surfaces.)

• A ban on whipping during races.

Newkirk also targeted Eight Belles' rider, Gabriel Saez, and her owner, Rick Porter. She said Saez should be suspended and that the $400,000 second-place purse should be withheld pending an inquiry. Newkirk wrote: "Eight Belles was doubtlessly injured before the finish line, yet Saez whipped her repeatedly in the home stretch."

Dr. Larry Bramlage, the on-call veterinarian at Churchill Downs on Derby Day, disagreed. Bramlage said that while galloping out after the race, Eight Belles fractured her forelegs, causing her ankles to collapse and making her fall.

"She appeared to be galloping out fine," Bramlage said. "I would have had no clue that anything was going wrong."

Saez jumped off her and the filly was euthanized immediately, before even her trainer, Larry Jones, knew she had been injured.

Jones defended Saez in an interview with The Associated Press, saying the 20-year-old Panamanian applied the whip only to prevent Eight Belles from bumping into the rail.

"This filly in every race has tried to drift toward the rail," Jones said. "It's her comfort zone, and Gabriel knows this. This kid made every move the right move, and I hate it that they're wanting to jump down his throat. He did not try to abuse that horse to make her run faster. He knew she was second best, that she wasn't going to catch Big Brown."