Melbourne Cup: death of racehorse Admire Rakti due to heart failure, cause still unknown

As the deaths of two of yesterday's Melbourne Cup runners reignites calls from animal welfare activists to tighten rules and ban whipping, an equine vet says establishing Admire Rakti's exact cause of death may take weeks.

An initial autopsy has revealed the Japanese horse died from a heart attack while seven-year-old stallion Araldo was put down after breaking a leg when it was spooked while returning to the mounting yard.

Dr Chris Whitton, an equine veterinarian at the University of Melbourne's veterinary hospital in Werribee where Admire Rakti's post-mortem examination was conducted, said it may take weeks to establish exactly why the horse died.

"One of the problems we have is that in about half of the horses that die sudden deaths like that, even with a full post-mortem, we don't get an answer," Dr Whitton said.

"In that other half where we get an answer, some of them are due to haemorrhage into the lungs and some of them are due to heart failure, sometimes for reasons again that we don't really understand very well."

While haemorrhage into the lungs was a possible cause of death, Dr Whitton said it was quite common in racehorses.

"Haemorrhage into the lungs happens in nearly all horses that race to some degree," he said.

"It's usually a small amount and of no consequence. But in some horses it happens to a greater degree and very occasionally and very rarely so much that they actually die.

"And the reason it happens is because horses are pushing themselves to the limit of biology. They've got a very great need for oxygen to their muscles and to do that they have a very high blood pressure in their lungs. The high blood pressure means that there's a risk of those vessels bursting."

'Horses push themselves as a matter of instinct'

Dr Whitton said whips and heat were not likely to be factors, and that racehorses pushed themselves hard as a matter of instinct.

"A lot of it's instinct. These horses have a very heightened flight response," he said.

"When they go, they go fast and they run until they think they need to stop.

"There's risk involved in doing anything with horses because they're such a powerful animal, even them just being kept in a paddock, they'll run into fences, they'll fall over and break things.

"You could make the case that because they're so well managed in racing that you reduce some of that risk because they're kept well, but yes, you increase the risk of other things happening because of the racing.

"But we know the risks in racing are fairly low. The death rate is less than one in 2,000 starts."

Admire Rakti was in good condition in the lead-up to the race, Racing Victoria's chief steward Terry Bailey told ABC News Breakfast.

"One of the advantages of the internationals is being based at Werribee at the quarantine [centre], these horses are [looked over] by vets everyday and the horse was even examined again on race morning by our vets and trotted up fine and fit as a fiddle," Mr Bailey said.

"These horses get better looked after than most humans. They have the best veterinary treatment under the sun.

"I'm very comfortable with how our trainers look after their horses."

'Deaths not isolated': animal protection groups

Animal protection groups said the deaths were not isolated and that racing put horses at risk.

In a statement, the RSPCA saidthe events were a "stark reminder" of the damage the sport can have on horses: "Injury and death are the price some horses pay for our entertainment."

"I'm sure that the connections and the people that worked with this horse and loved this horse would never have wanted that to happen, so we need to be able to learn from that to make sure that it actually never happens again wherever possible," the RSPCA's Victorian chief executive, Liz Walker, said.

Coalition for the Protection of Racehorses campaign director Elio Celotto said roughly one horse had been killed every three days in the past 12 months due to horse racing.

"This is a sport that has been doing what it wanted to do for the last 200 years, and now it's starting to realise that it needs to make some changes," Mr Celotto said.

Australian trainer David Hayes, who won the 1994 Melbourne Cup with Jeune and yesterday ran Unchain My Heart, who finished 16th, said he was surprised and saddened by Admire Rakti's death.

But he said the call from animal welfare activists to ban the whip during races was an overreaction.

"I watched Admire Ratki because he's one of the fancied horses in the race," Mr Hayes said.

"He was beat probably at the 600-metre mark, which was out of character, and the jockey basically eased him down the line because he knew something was wrong.

"He might have given him one or two taps and then sat up on him.

"The whips are padded and he would have had a lot less whips than the winner."

Mr Hayes said those involved in horse racing had the animals' best interests at heart.

"The reason you work with animals is because you love them," he said.

"They like to compete. They're bred to compete. And they do it 99 per cent of the time very healthily."

Araldo trainer calls for tighter security

Meanwhile, the trainer of Araldo, the second horse to die after yesterday's Melbourne Cup, has called for tighter trackside security.

The seventh place-getter was put down after breaking a leg when it was spooked by a large flag waved in its face as it headed back to the mounting yard.

Racing Victoria will speak to the Victoria Racing Club (VRC) about whether restrictions on items like flags were being adhered to.

Araldo's trainer, Mike Moroney, was also seeking answers.

"We're very proud of the way he ran, very proud of him," Mr Moroney said.

"To think that he finished the course and was just on his way back and that happened is a hard pill for everyone around to swallow, but we know that it will be reviewed and if it can be helped [avoided].

"If they've got security guards along that perimeter where the horses are, [and] that they are people who know horses and know what can set a horse off."

Victorian Premier Denis Napthine told Fairfax Radio the horses' deaths were terrible accidents but said there may be lessons to learn in the case of Araldo.

"Both the VRC and Racing Victoria will look at how we better manage horses in crowds," Dr Napthine said.

"The VRC, to their credit, have already put in a big tunnel to separate horses from people.

"Whether there's further changes in terms of management of the crowd, management of the horses, these are things the industry will look at, because the industry genuinely cares about its horses."