Victorian trainer Kylie Vella has been charged over the race day treatment of a horse with an anti-inflammatory medication.

Racing Victoria stewards have issued three charges stemming from a urine sample taken from the Vella-trained Admiral's Joker after he won at Flemington on May 25 last year.

The first charge states Vella administered or caused to be administered, Diclofenac (using Voltaren) to Admiral's Joker inside one clear day before the race.

Vella has also been hit with two alternative charges relating to the positive swab.

The charges will be heard by the Victorian Racing Tribunal on a date to be fixed