Trainer Symon Wilde has been fined $15,000 over a positive swab returned by a horse in his care which won at Warrnambool in December.

Dexamethasone, a short-acting corticosteroid, was detected in a post-race urine sample taken from Florida Pearl after she won a benchmark-64 race on December 27.

Wilde pleaded guilty to bringing a horse to race when a prohibited substance was detected in its system, and the Racing Appeals and Disciplinary Board issued the fine on Thursday.

Florida Pearl has been disqualified from her win.

MELBOURNE, April 27 AAP