Father and daughter training partners Terry and Karina O'Sullivan have lodged an appeal against their cobalt convictions.

The O'Sullivans were last week hit with a disqualification until 2020 after the Racing Appeals and Disciplinary Board found them guilty of administering or causing to be administered a prohibited substance.

They had faced nine charges laid by Racing Victoria stewards after two horses returned excessive cobalt readings, well above the the then threshold of 200 micrograms per litre in urine in pre-race samples in 2015 and 2016.

The threshold is now 100mcg/L.

The pair had the most serious charges dismissed by the RAD Board of administering, or causing to be administered, a prohibited substance, being cobalt, for the purpose of affecting the performance or behaviour of a horse in a race.

Terry O'Sullivan said they had lodged appeals with the Victorian Civil and Administrative Tribunal.

An appeal date is yet to be determined and the two are continuing to train pending the hearing.