John Oliver tackled America’s opioid crisis on Last Week Tonight on Sunday. He started his reporting with a dog who overdosed after someone threw a bag of heroin over the fence of a doggy day care center. (See below for Oliver’s impression of a stoned dog.) “Rampant heroin abuse near a doggy day care is the first case that McGruff the Crime Dog is actually qualified to solve,” Oliver noted. According to Oliver’s research, some 2.6 million Americans are addicted to opioids, many of whom start with an addiction to prescription painkillers, but turn to heroin, in part because it is cheaper than drugs like Oxycontin, Percocet and Vicodin. In the U.S., doctors have written more than 250 million prescriptions for painkillers, according the U.S.