FDA: Pet food tainted intentionally?

Chinese manufacturers might have intentionally added a chemical linked to pet deaths and illnesses into a protein-powder ingredient in pet foods, federal government regulators said Thursday.

Stephen Sundlof, chief veterinarian for the Food and Drug Administration (FDA), said melamine, which has turned up in more than 100 brands of cat and dog food, might have been used to falsely boost the apparent nutritional content of rice protein.

"That's still a theory, but it certainly seems to be a plausible one," he said.

Melamine, an ingredient in plastics and fertilizers that could lead to kidney failure in animals, has contaminated rice protein and wheat gluten in pet foods produced in Canada and the United States.

The chemical compound reportedly also has tainted corn gluten added to pet food sold in South Africa, the FDA said.

Melamine can skew test results to make a product appear more protein-rich than it really is, Sundlof said. That raises the possibility the contamination was deliberate.

The fact that three protein sources from China were contained with the chemical adds credibility to the theory, he said.

FDA officials said they are investigating whether the chemical might have been added intentionally as a way to charge more for an inferior product.

But the FDA added that it would not be able to check its theory without getting approval from the Chinese government to inspect the factories where the rice protein and wheat gluten were produced. The FDA said it "fully expects" to get cooperation from the Chinese government.

The Chinese government has said the contaminated wheat gluten was an industrial product not meant for pet foods and therefore was not its regulatory responsibility.

The FDA said it had traced the contaminated wheat gluten to Xuzhou Anying Biologic Technology Development in Jiangsu province just north of Shanghai.

The company's general manager, Mao Lijun, said earlier this week that his company was investigating the matter. He declined to answer questions.

The FDA also said domestic manufacturers share some responsibility for ensuring the safety of their pet foods.

"There is an industry responsibility to know who their suppliers are and to exercise some diligence," said Michael Rogers, head of the FDA's Division of Field Investigations.

California-based Natural Balance Pet Foods, which this week voluntarily recalled four types of pet food containing rice protein, said it would be wary of putting any Chinese-made ingredients in its products.

"I can't imagine we'll be using Chinese ingredients again. If we do, clearly it will be with much scrutiny," spokesman Daniel Bernstein said.

Bernstein said the four recalled brands, containing venison and brown rice or venison and green peas, were manufactured by Diamond Pet Foods, of Meta, Mo. Diamond, in turn, bought the rice protein from Wilbur-Ellis, a San Francisco-based company that sells animal feed.

Wilbur-Ellis said Thursday it was recalling all the ingredients it had distributed to five U.S. pet food manufacturers.

The FDA and Agriculture Department also were investigating whether some pet food made by one of the five companies supplied by Wilbur-Ellis was diverted for use as hog feed after it was found unsuitable for pet consumption.

Material from The Associated Press is included in this report.