A former Olympic equestrian competitor from Santa Rosa faces charges of animal cruelty for her treatment of a thoroughbred mare named Valerie.

Gwen Stockebrand, 57, will be arraigned at 8:30 a.m. today in Sonoma County court for depriving the horse of care from June 1 to Sept. 8. The complaint filed Dec. 14 says she failed to provide sustenance and drink.

Sonoma County animal control officials had been investigating the animal's well-being since last year, District Attorney's Office spokeswoman Christine Cook said.

Stockebrand couldn't be reached for comment Tuesday.

Valerie was one of two horses taken to Lost Hearts and Souls Horse Rescue in early September by a man who said Stockebrand had given him the two emaciated horses, said Laura Ponter, a volunteer with the rescue group who has helped care for Valerie.

"Valerie was skin over bones," said Ponter. "We didn't think she'd make it."

A veterinarian recommended the mare be euthenized, Ponter said. However, she and others at the ranch, run by Betsy Bueno of Santa Rosa, saw a spark in her eye, which can indicate an animal may thrive if nourished back to health, she said.

"We rolled the dice and on her and we won," Ponter said. "She's doing well."

A second animal, a mare in her 20s named Sister, later died, Ponter said. Stockebrand hasn't been charged in connection with the horse's death.

The Sonoma County Horse Council in 2010 named Stockebrand to the Equus Hall of Fame "in recognition of her contribution to advancing the discipline of Dressage," according to the council's website.

Stockebrand belonged to several U.S. equestrian teams and competed in the Olympics, the World Championships and the Pan American Games.

In a separate case, a Windsor man and his niece are being charged with animal cruelty toward two horses.

One of the animals died and another remained under the care of the Santa Rosa horse rescue group, said Sonoma County District Attorney's officials and animal advocates.

On Thursday, Mark Ross, 48, of Windsor and his niece Nicole Ross, 28, of Rohnert Park are to be arraigned They are suspected of animal cruelty involving a thoroughbred gelding named "Skim the Excess," also known as Eddie, that died, Cook said.