Victorian racing officials have introduced procedural changes for the remainder of the 2014 Melbourne Cup carnival in response to the incident that led to Araldo being euthanised on Tuesday.
Seventh-placed Araldo was leaving the track via the pathway to the mounting yard when it was spooked by a large flag in the crowd, causing it to veer and break its leg in a fence.
It was euthanised humanely hours later after experts determined the injuries were too severe to recover from.
Racing Victoria has announced that for the remainder of the carnival, horses competing in group one races will be escorted directly to the mounting yard via the clocktower gate, bypassing the path and any crowd interaction.
RV also revealed it would not allow flags larger than one metre by one metre to enter the racecourse, with extra security to be employed in horse movement areas.
Additional veterinary resources will also be in place for the remainder of the carnival.
The Japanese stayer Admire Rakti, the pre-race favourite for the Melbourne Cup, died of acute heart failure though the cause may be unknown until the full results from a post-mortem says Racing Victoria's chief steward.
The six-year-old collapsed after yesterday's 3200m race having faded badly and finished in a distant last place behind German raider Protectionist.
A post-mortem was conducted yesterday.
Chief steward Terry Bailey says all indications are that Admire Rakti passed away due to heart failure, but they need need to get the autopsy results to tell the full story.
"These horses are looked after by the finest equine vets in the world and we will just have to wait until we get the results."
Bailey says the horse had not appeared to have been in any difficulty prior to the race and had been inspected by veterinarians earlier in the day and given the all clear.
The favourite and an impressive winner of the Caulfield Cup last month, carried the top weight of 58.5 kilos, though Bailey says he doubts that could have been the cause of the horse's death.
"In my view and my experience 58.5 kilos wouldn't be attributable to what happened," he says. "It's just unfortunately one of those things."
Admire Rakti was one of two horses to die after the race, with seventh-placed Araldo put down after suffering a leg injury when he was spooked by a spectator waving a flag while returning to the stalls.
The deaths of both horses cast a pall over the $7 million race, with the German horse Protectionist romping to victory after bursting clear with about 200 metres to run.