I ate dog just once, and it was an accident. A Chinese scrap-metal dealer with whom I'm friendly invited me to a fancy hotpot restaurant in Chongqing. As the waitress delivered bowl after bowl of dunkable vegetables and raw meats for cooking at our table, I pointed to one and asked: "What's this?" My friend's answer, in heavily accented English, sounded like "duck." It tasted like a meaty hair ball.

As the magnitude of my mistake sank in, I thought of Yulin, the southern Chinese town infamous for its annual dog meat and lychee festival, which opens this week. In recent years, the festival has become synonymous with animal cruelty, attracting celebrity outrage from the likes of Ricky Gervais and Leona Lewis. But it's also emblematic of a larger failure — one that my unintentional experiment instantly brought to mind.

For years, scandals have been undermining confidence in China's food supply, ranging from plasticizer in baby formula to "poisonous fake mutton" sold to (gulp) hotpot restaurants. In 2014, authorities shut down a decade-old, nationwide ring that had been selling some 70,000 diseased pigs a year to underground slaughterhouses.