The horse fell at the last hurdle, when running fifth.
Local media reported that course veterinarian Harry Frauenfelder put the death down to a ruptured aorta before the fall.
Two Australian horses have died on the track so far this season from injuries suffered in jumps falls.
Casa Boy was euthanised on the opening day of the season, at Warrnambool.
Two weeks ago, at Morphettville, Hammerblow was fatally injured in a trial.
Jumps racing in Australia, restricted to Victoria and South Australia, is under scrutiny over the sport's death toll.
Animal welfare groups want it banned.