WARNING: Video contains graphic footage that may be disturbing to viewers
Tuesday's Melbourne Cup is being overshadowed by an expose that one researcher says is shaking the Australian horse-racing industry to its core.
Footage of trained and celebrated racehorses whipped and beaten, given electric shocks, kicked in the head and slaughtered at pet food knackeries where the law says they shouldn't be.
An ABC investigation is putting the heat on the NSW Racing industry, as it denies the scale of the carnage.
It says about 34 horses a year end up at the slaughterhouse, but the 7:30 report investigation revealed there were more than 4000 racehorses in the past year killed at one abattoir alone - with their identities laid bare due to the brandings of iconic horse studs.
Professor Paul McGreevy, from Sydney University's School of Veterinary Science, said the worst thing about the abuse was the horses were highly-trained animals that could easily be led peacefully to their deaths. Instead, they were dragged and beaten in distressing states.
"What's particularly appalling about this is that these are not feral animals that must be herded and pushed and dragged because they are intractable - these are trained former racehorses that could have been led gently with a head collar to their demise," he told Checkpoint.
Professor McGreevy, who has done extensive research into the treatment of racehorses over 25 years, said the ABC report had shocked both the industry and the nation to its core.
"We were seeing images of horses that were not meant to be where they ended up, in abattoirs and knackeries," he said.
"There was a very bold step by Racing New South Wales to say that horses would not end up in those situations.
"The ABC journalist showed me the footage and you could very quickly see that the impact would be profound, the Australian public would not forget the vision of electric shock devices being used on horses, horses' heads being kicked and horses receiving multiple bolt shots to the head, on one occasion five shots and the horse died.
"So I think it was that combination of the animal being in the wrong place and it being treated so poorly that has galvanised opinion. The racing industry has certainly stepped up and ensure that this never happens again."
The veterinarian said the horse breeders working with the horse racing industry were estimated to be supplying 13,000 to 14,000 animals each year, whereas some racing industry figures admitted 10,000 would be enough. He said there were invested interests keeping the numbers high, motivated by money.
"The racing industry's job is to put on races and have a high regard for welfare of the horses and the integrity of the horses on the track, the integrity of the races and the safety of the jockey. The breeding industry supplies the animals for that spectacle and there are big dollars involved in getting foals onto the ground.
"There are big forces at play who want to keep the breeding industry very buoyant."
Professor McGreevy said the shocking ABC report had come at a time when the government was already looking at a national core traceability register, in an attempt to keep every horse under a monitoring system to determine where they end up.
He said the drive to find the latest genetically-gifted horse racing was fuelling the problem exposed by the report and that 35 percent of the horses breed for racing never made it to the track.
"Our obsession with finding the latest greatest, fastest two-year-old is probably at the core here and because our interest in finding these young horses means we do get them into work very early and the rather troubling statistic is only 65 percent make it to the track... we need to ask why that is and breed for more durable horses."
He said the the government, and particularly the Green Party, was pushing for reforms and changes in attitudes, and that many people were now questioning the social merits of racing events like the Melbourne Cup.
"Not many people there take much notice of the horses, they're there for the nibble and the tipple... but more and more people are saying enough to the Cup."