Moorpark, Calif. — Ann Romney talks openly about her love of horses. Ever since her multiple sclerosis was diagnosed more than a decade ago, the presidential candidate’s wife has turned to riding for therapy and relaxation. But her simple pastoral hobby has become more complicated as it has become more competitive, and she is less open about her involvement in dressage, a rarefied, ritualized sport often referred to as “horse ballet.”

She has competed in amateur rounds of major dressage tournaments. She has funded dressage horses and riders of Olympic caliber. She and her husband, former Massachusetts governor Mitt Romney, have at least part-ownership of four warmbloods (as the kind of horse often used for dressage is known), according to a campaign spokeswoman.

“My horses rejuvenate me like you can’t believe” she told Fox News last week. “They give me balance. They give me energy. I think it’s because I love them so much.”

Dressage demands agility and finesse — and money. Ann Romney’s involvement in the sport has allowed her access to the heady world of high-level competition, but it has also exposed her to horse dealing. Two years ago, it resulted in a lawsuit against her alleging fraud in the sale of one of her horses. And that lawsuit provided testimony in which she spoke in unusual detail about the benefits — and the costs — of riding.

Dressage, whose roots date to ancient Greece, got its name (and its pronunciation, dress-AHGE) from a French term that means “training.” According to the U.S. Dressage Federation, “its purpose is to develop the horse’s natural athletic ability and willingness to work making him calm, supple and attentive to his rider.” Unlike other types of holdings, dressage horses are living investments whose value can tumble with the wrong turn of a hoof.

The Romneys, through a campaign aide, declined to tally how much they spend on dressage, saying, “We are not required to disclose this information.” But some of their animals cost more than $100,000, and the Romneys continue to sink tens of thousands of dollars into year-round training and feeding, plus veterinary bills.

Last year’s lawsuit, from which Ann Romney was eventually dropped as a defendant, led to a deposition during which she offered moving insights into her equestrian life. She had loved horses as a girl in Michigan, and she didn’t return to them until she turned 50. “It’s when I was diagnosed with M.S.,” she said. “And I was losing most of the function of my right side. And I decided I needed to go back and do what I loved, before I couldn’t do it anymore.”

Getting back on the horse

Soon after she resumed riding, Romney enrolled in a clinic run by an accomplished trainer and German emigre named Jan Ebeling, owner of state-of-the-art stables north of Simi Valley at a ranch known as the Acres. Ebeling and his wife, Amy, hosted Romney often. “I would probably come out once a month to once every six weeks for about a week,” Romney recalled.

The Acres is home to a 40-stall barn, indoor arena, dressage ring and obstacle courses. There are steep and dusty trails on the state-owned acreage nearby. Trusted James Herriot-type veterinarians and farriers and a young German assistant tend to the animals and take them through their paces; other horses, nursing injuries or strains, are pampered in the barn.