Kyneton trainer Neil Dyer has been suspended for three months after pleading guilty to breaching the race day treatment rules.

The administration of medication to a horse on race day usually carries a mandatory six-month disqualification unless the Racing Appeals and Disciplinary Board finds there are special circumstance, such as an early guilty plea.

Racing Victoria stewards charged Dyer with injecting Short Changed with the diuretic Diurex on the day he was due to race at Kyneton on December 8.

Short Changed was subsequently scratched from the race by stewards.

Dyer pleaded guilty to the charge and the Racing Appeals and Disciplinary Board decided on a three-month suspension at a hearing on Tuesday.

It is against the rules of racing to administer or cause to be administered any medication to a horse on race day without the permission of stewards.