An investigation by the broadcaster's current affairs program "7.30" also found evidence of cruelty to the dogs in the sport. Trainers breed freely in hopes of getting a winner and then kill about 17,000 dogs a year for failing to measure up, ABC said.
Australians bet about $3 billion Australian ($2.85 billion U.S.) a year on greyhound racing, with the country ranking number three in the world.
Smaller greyhound trainers complain the regulations are enforced inconsistently, favoring big kennels.
"Eighty per cent of greyhound trainers are looking for something to dope their dogs," Christos Aletos, a Sydney trainer, told ABC. "I can't compete with the high quality of drugs when they use them."
Drugs were found in the systems of more than 70 dogs this year, many of them also used by humans for recreation or performance enhancement. They included cocaine and caffeine.
Ted Humphries, a veterinarian whose whistle-blowing sparked an investigation 10 years ago, said cocaine is most effective when gotten into the greyhound just before a race.
"The improvement is quite remarkable," he said. "These drugs are stimulatory and it will make a greyhound do its utmost to win."
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