The tainted pet food episode has taken the Food and Drug Administration by surprise. Chinese producers say it's an open secret there that the industrial chemical melamine is often added to animal food, but it wasn't on the radar screen of U.S. regulators.
For one thing, the chemical wasn't considered very toxic. Now, the FDA's new food safety chief says the agency has learned that melamine's breakdown products are toxic, causing the formation of crystals in the kidneys. That might explain why older pets with lower kidney function are especially susceptible to melamine effects.
One former FDA staffer says the pet food episode is a warning sign pointing to a major gap in the FDA's ability to deal with imported food contaminants.
"There but for the grace of God go some humans," he says.