Sweetest Thing, who won the July 6 Dance Smartly Handicap (Can-IIIT) at Woodbine in what turned out to be her final start, has been retired after trainer and former co-owner Roger Attfield detected some swelling in an ankle following a workout."It was in the area that might have made it hard for her to return to the top of her game," said owner Roy Jackson of Lael Stables. "It was best to retire her."The Dance Smartly was Sweetest Thing's sole start for Jackson, who bought the 4-year-old Candy Stripes filly from Attfield, Michael and Phyllis Canino, and William Werner earlier this year. Sweetest Thing beat males in winning last year's classic Breeders' Stakes at Woodbine on turf and was Canada's champion grass mare. She also won last year's Wonder Where Stakes on turf and this year's Bewitch Stakes (gr. IIIT).Bred by Kinghaven Farms and produced from the Lear Fan mare Escape Reality, Sweetest Thing retires with six wins from 13 starts and earnings of $857,094, all on grass.