A Racing Victoria investigation has concluded Melbourne Cup favourite Admire Rakti died from heart failure as a result of a cardiac arrhythmia soon after trailing the field home in the great race.
The deaths of Admire Rakti and Araldo, who was euthanised after breaking a leg following an incident with a spectator, brought worldwide attention via many mainstream media outlets.
University of Melbourne experts conducted an autopsy on the seven-year-old while Racing Analytical Services Limited technicians tested many samples taken from Admire Rakti.
The testing showed no unnatural factors in Admire Rakti's death but the discovery of "uncommon changes to the horse's kidney" prolonged the probe.
Specialist testing of Admire Rakti's kidney found no evidence of any toxic substance with a variety of international experts, including Dr Rachel Cianciolo of Ohio State University, concluding the kidney changes were due to rapid natural decomposition.
Stewards reviewed Admire Rakti's veterinary records and interviewed connections to gather information relating to his behaviour before the race but found nothing out of the ordinary.
Stewards were also satisfied with jockey Zac Purton's tactics on the stayer.
"Following an extensive post-mortem examination and investigation we are of the opinion that Admire Rakti died of acute cardiac failure as a result of a cardiac arrhythmia that can be attributed to natural causes," from Dr Brian Stewart, RV's Head of Equine Welfare and Veterinary Services, said in a statement.
"We did find uncommon changes in Admire Rakti's kidney which required additional analysis and review by kidney experts. It was ultimately determined that those changes can be attributed to natural causes.
"This death has been categorised as a sudden death which are thankfully very uncommon in Victorian thoroughbred racing with the recorded incidence 0.007 percent of an average 43,500 starts each season."
