The drug is administered to about 94 per cent of race horses.
The study looked into almost every horse race in the United States and Canada over a period of 12 years – and found that around one in 10,000 race starts resulted in a race-day sudden death for a horse.
Horses who were recorded as being administered with furosemide were 62 per cent more likely to experience sudden death.
Furosemide is commonly given to prevent exercise-induced bleeding in the airways and is also associated with enhanced racing performance.
The ethics of race day medication are controversial, with furosemide already restricted or prohibited on race day in certain circumstances, depending on jurisdiction.
