Racing Vic criticised in cobalt appeal

Four embattled Victorian trainers who face career-ending disqualifications after their horses tested positive for cobalt want a tribunal to "right the wrongs" of racing stewards.

Father-and-son training partners Lee and Shannon Hope on Friday joined Mark Kavanagh and Danny O'Brien's appeal against their disqualifications at a Victorian tribunal.

Kavanagh and O'Brien are fighting respective three and four-year disqualifications they received after five horses returned positive results for cobalt in 2014.

The Hopes are also appealing three and five-year disqualifications for cobalt at the Victorian Civil and Administrative Tribunal.

"Your honour has the capacity to right a wrong that has been inflicted on Lee Hope, Shannon Hope, Mark Kavanagh and Danny O'Brien," Rahmin Dekretser, representing the Hopes, told Justice Greg Garde on Friday.

Like Kavanagh and O'Brien, the Hopes say the Perth-based ChemCentre and Hong Kong Jockey Club laboratories were not accredited to test for cobalt at the time horses from their stables returned positive results.

Dekretser said Racing Victoria stewards were aware the laboratories lacked the proper accreditation, but continued to rely on their services.

"The stewards knew full well the rules had not been complied with and they remained silent," he said.

"But like a thistle in a steward's riding boot, the trainers discovered ... there hadn't been compliance with the rule."

Kavanagh and O'Brien blame vet Dr Tom Brennan for giving their horses a substance containing cobalt without their knowledge.

"The number of people who have been scarred by this ... has been amazing, and much of it is down to Brennan," the pair's lawyer Damian Sheales said on Friday.

"Brennan is such a liar."

Sheales also criticised the way RV conducted its investigation of positive cobalt readings, despite the resources available to them.

"The way this case been conducted, you just shake your head," he said.

Kavanagh was disqualified in 2016 for three years, and O'Brien for four years, but they continue to train under a stay of proceedings pending the outcome of the VCAT appeal.

The Kavanagh-trained Shocking won the Melbourne Cup in 2009.

The Hopes were subject to the first cobalt inquiry in Victorian thoroughbred racing, and their case was viewed as a test of whether the declared cobalt raceday threshold of 200 micrograms per litre of urine was enforceable.

The national rule came into effect in January 2015 and this year the threshold was halved to 100mcg/L.

The Hopes were allowed to make closing submissions in Kavanagh and O'Brien's case because of overlapping issues between all four trainers.

After 23 days of evidence, Justice Garde has reserved his decision.