Sydney trainer Con Karakatsanis and his father Tony have failed in their bid to overturn the guilty verdict in their stomach-tubing case.

The pair had hefty sentences handed down after stewards raided a stable at Flemington on a tip-off that they were preparing to treat the horse Howmuchdoyouloveme hours before it raced during last year's Melbourne spring carnival.

The Racing Appeals and Disciplinary Board (RAD) found them guilty of intending to treat a horse within the 24 hours before it raced, disqualifying Con Karakatsanis for nine months and his father for two years.

Acting on the information received, stewards staked out the Flemington stable where Howmuchdoyouloveme was housed, moving in minutes before the horse was due to make the short trip to the racecourse.

They found a chaff bag containing tubing equipment and a mixture in powder form.

It was accepted the powder would not have been prepared for pre-race use.

No evidence was presented at either the initial hearing or at the appeal conducted before the Victorian Civil and Administrative Tribunal (VCAT) that either of the accused had administered a treatment to the horse.

Stomach-tubing is a process which delivers fluid directly into a horse's stomach through a tube passed through its nose.

But Judge John Nixon, who heard the case in VCAT, agreed with the RAD Board verdict.

He is yet to make a decision on the penalty.

VCAT will reconvene on a date to be fixed to hear submissions on the penalty.