The Food and Drug Administration has blocked imports of wheat gluten from a company in China, saying that it suspects the gluten was contaminated with melamine that found its way into pet food. Tainted food is believed to have caused kidney failure in dogs and cats across North America.
Last month, Menu Foods of Canada recalled nearly 95 brands of "Cuts and Gravy" pet food. And now there have been recalls from three more companies: Nestle Purina Pet Care, Del Monte Pet Products and Hill's Pet Nutrition.
Initially, pet owners were told the contaminant might be a drug used as rat poison. Last week, the FDA said it had found melamine, a chemical used to make plastic products, in the wheat gluten samples it tested.
Melissa Block talks to Elizabeth Weise of USA Today, who has been covering the story.