The Canadian racing and equestrian community mourns the passing of Shirley Laura Thomas Prosser on April 29, 2026, in her 90th year.
Shirley became an accomplished equestrian at a young age, beginning with ponies and hunters before she got her first jumper, Pale Face, at the age of 12. Just five years later she would venture from her hometown of Aylmer, Quebec, to compete in Toronto and secure a spot on the Canadian Team for the prestigious North American indoor fall circuit.
At 18, Shirley found herself travelling to Europe as a member of (and first woman on) the Canadian Equestrian Team alongside Jim Elder, Walter Pady, L.J. McGuinness in 1954. The appearance of a young woman with a long blonde braid riding on an international team caused quite a stir, as “they weren’t used to seeing attractive young gals ride these horses,” remarked Moffat Dunlap in a video tribute in 2008 honouring her induction into the Jump Canada Hall of Fame. Shirley rode her big grey jumper named Revlon’s White Sable (whose name reflected her father’s influence as president of Revlon Canada). The pair had a successful tour, and won the Government of Ireland Trophy in Dublin with the only clear round of the competition in a field of 65 world-class riders. The newspaper English Sporting Life nicknamed her the ‘Teenage Jumping Ace’.
“She definitely opened the door for female riders,” said FEI steward Harriet Cherry in the video. “She could do it, and other girls thought ‘so why can’t I?'”
Shirley retired from international competition following an injury sustained in London, but continued to be involved in the sport as a hunter rider, owner and breeder, later devoting herself to breeding and racing Thoroughbreds at her Box Arrow Farm in Portland, Ontario. Often sending horses out in partnership with Gordon C. Colbourne, horses she bred and owned raced at tracks including Woodbine, Fort Erie, and various US venues.
Notable horses bred by Box Arrow Farm include the stakes-placed Jazz Nation (City Zip – Jazz Star, by Dixieland Band) and Poseidon Steel (Frac Daddy – Blue Waters by Speightstown), a multiple winner at Woodbine. The good six-year-old mare Chipotle Pepper (Big Screen – Hot Cross Buns, by Singing Saint) who has won at Delaware Park, Oaklawn Park, Parx Racing, and Woodbine, including her most recent victory on May 2 of this year. Beau Fasa was owned by Box Arrow and won multiple stakes including the Niagara Handicap and King Edward Gold Cup at Woodbine, and the Pennsylvania Governor’s Cup and Captain My Captain Stakes. Shirley was also a long-time member of CTHS-Ontario.
Gordon Colbourne, the Box Arrow Farm trainer for the past 47 years, recalled her passion for racing and staying connected. “She couldn’t always get to the racetrack, but she never missed a race. She watched everything and stayed completely engaged with the horses.”
“Her father had a couple of racehorses, and she got interested from there,” he said of how she got her start in the industry. “We started with just one inexpensive horse, and like it always does, it grew from there. We claimed Beau Fasa for $3,000, and he went on to win multiple graded stakes. That kind of story meant a lot to her.
“She was never about big numbers. Even at her peak, maybe ten horses in training, and more recently just four or five. It was always about the enjoyment.”
Gordon noted that her love of the industry extended far beyond racing. “She loved the whole business. We went to a lot of sales together, especially in Kentucky and here in Ontario. That was a big part of it for her.”
Her daughter Ruth is taking over Box Arrow, “and she’s just as passionate. The broodmares and racehorses are staying in the family, which is exactly what Shirley would have wanted.”
Shirley was predeceased by her daughter, Laura, and leaves her son Christopher, daughter Ruth (Sherrie), three grandchildren and five great-grandchildren. The family has asked that any donations in her memory be made to Kick in for Kids at the Rideau District High School in Elgin.
(Photo courtesy Brent van Hooft)
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