Comtesse de Loir began her career as a racehorse by winning a race for newcomers over 1600 metres at Longchamp Racecourse in September, beating Val Divine by one and a half lengths.
Ridden by Desaint, she started a 16/1 outsider against thirteen opponents including Hippodamia, La Tulipe, Paddy's Princess, Rose Bed, Dumka (winner of the Poule d'Essai des Pouliches) and Pale Ale (Prix Penelope).
Comtesse de Loir looked fit to run before the race and finished strongly but proved no match for Paulista and was beaten into second place by four lengths.
Under a hard ride from Desaint, Comtesse de Loir produced a strong run in the straight to challenge the odds-on favourite Allez France in the last 100 metres.
[5] On her first appearance of 1975, the four-year-old Comtesse de Loir finished third behind Allez France and Card King in the Prix Ganay at Longchamp on 4 May, with Hurry Harriet and Dahlia in fifth and sixth.
She was then sent outside for France for the first time to contest the Coronation Cup at Epsom Downs Racecourse in June and finished fourth behind Bustino, Ashmore and Mil's Bomb.
In late October she ran in the Canadian International Stakes at Woodbine Racecourse in Toronto and finished second, beaten half a length by the 1974 Epsom Derby winner Snow Knight, who went on to be voted American Champion Male Turf Horse.
The filly's last race was the Washington, D.C. International over one and a half miles at Laurel Park Racecourse in which she was opposed by Snow Knight, Dahlia, Nobiliary, Star Appeal and On My Way.
Held up by Desaint in the early stages, he produced her usual strong run in the straight but failed to overhaul Nobiliary and finished second, beaten three quarters of a length.