LEXINGTON, Ky. - Aaron and Marie Jones's champion racemare Riboletta will return to training in California after falling victim to the mare reproductive loss syndrome that has swept central Kentucky. Riboletta will come out of retirement and be sent back to trainer Eduardo Inda.

According to Frank Taylor of Taylor Made Farm near Nicholasville, Ky., where the Joneses boarded Riboletta, the 6-year-old Roi Normand mare was found to have aborted a Forestry foal about two weeks ago. Forestry, a Storm Cat horse whom the Joneses also raced, stands at Taylor Made for $50,000. Riboletta, like many of the mares affected by the syndrome, was bred in February.

Taylor said that Riboletta may return to Kentucky next season to be bred.

Riboletta, North America's champion older mare in 2000, is one of the more notable mares to be affected by the mysterious syndrome. So far, researchers and veterinarians have not identified a cause for the abortions, which have affected both late-term foals and early-term fetuses in at least 1,200 cases throughout central Kentucky. Theories have ranged from caterpillars to pasture toxins to cherry trees, but so far the cause remains elusive.

Riboletta is scheduled to arrive at Inda's Hollywood Park barn on Tuesday, the trainer said.

Aaron Jones said that two veterinarians - Larry Bramlage in Kentucky and Rick Arthur in California - inspected Riboletta before the decision was made to return her to training.

"We wanted to be doggone sure that she can come back," Jones said. "They are in the opinion that she can come back in training. We've done a very thorough physical exam. She looks like a good candidate. She got in foal early. She aborted and so did Manistique and several other maiden mares.

"If it all goes great, she could come back in the fall. We'll get some recommendations from Dr. Bramlage and Dr. Arthur. They want to monitor her quite carefully.

"I've even thought of taking a string of horses to Belmont Park this fall, but it's just a thought. We'll create something to keep us busy."

Riboletta has not started since finishing seventh of nine as the heavy favorite in the $2.1 million Breeders' Cup Distaff at Churchill Downs last November. She emerged from the race with a ligament injury that prompted her retirement.

Last year, Riboletta won 7 of 11 starts and $1,384,860, including 6 major stakes - the Santa Margarita, Hawthorne, Vanity, Clement Hirsch, Ruffian, and Beldame.

Inda said he does not expect Riboletta to be ready to race until the end of the summer.

"She's doing good," he said. "She's a little bit heavy because she's been doing nothing in the paddock, just eating grass.

"I think she could be ready at the end of Del Mar, but I don't know if I'll find a race."

Inda would like to point Riboletta to a defense of her wins in the Ruffian Handicap and Beldame Stakes in the fall at Belmont Park.

"I hope we get her ready for the races in New York that she won last year," he said. "She was very impressive.

"I told Mr. Jones, 'If anything shows up, we'll stop.' We won't take any chances to get to the races.

"I'm very excited. She made my year."

- additional reporting by Glenye Cain