Athabascan has been ruled out by RV vets from the Melbourne Cup. 

The Melbourne Cup field is down to 23 starters following the scratching of Athabascan following a Racing Victoria veterinary inspection. 

All 24 runners in the Melbourne Cup (3200m) on Tuesday underwent veterinary examinations on Monday, having undergone pre-acceptance inspections last week. 

On examination on Monday, the John O’Shea and Tom Charlton-trained Athabascan was found to have cardiac arrhythmia. 

ECG reports and the results of blood test taken from the stayer were forward to three independent experts specialising in equine internal medicine, including cardiology. 

"They each independently advised that, due to the nature of the cardiac arrhythmia, Athabascan should undergo further extensive testing before being permitted to race again on the grounds of safety," RV said in a statement. 

"Acting on these opinions and having considered additional material provided by the stable, RV veterinarians advised the Stewards that in their view the horse should be withdrawn from the Melbourne Cup due to an increased risk of a cardiac episode.  

"Accordingly, the Stewards acting on veterinary advice, ordered the withdrawal of Athabascan." 

The remaining 23 horses were passed fit to race on Tuesday."