Talented mare Heidilicious was fighting for her life on Sunday afternoon after crashing into a fence at Flemington.
The mare was being saddled up for the Group Two Blazer Stakes (1400m) when she reared up, got rid of her head gear, and galloped out of control and from the bird cage area.
Trainer John Sadler said there nothing anyone could do to stop her.
“She was heading back to her stable out of control, travelling very fast, and ran in to a fence near the stable,” Sadler said.
“The vets are trying to save her but at this stage it looks like she will have to be put down.”
A daughter of Zabeel out of Danehill mare Kerkira, Heidilicious won two of her eight starts.
She showed staying promise last winter when she finished third to Shootoff in the Queensland Derby (2400m).