Deliberate Tampering

I am quite disturbed by this report, suggesting that the melamine in the pet food problem isn't an accident, but rather, quite deliberate, in order to fool chemical tests regarding protein content. Analytical chemical methods in use apparently aren't sophisticated or selective. The tests look for nitrogen content, and since protein is nitrogen-rich, in general, the methods work. But any source of nitrogen can fool the test, including, apparently, melamine:

Natural Balance, a Pacoima-based company, is "99.9 percent sure" that a rice protein made in Asia is responsible for the melamine detected Tuesday in some of its venison-based pet foods, company President Joey Herrick said.

"It was pretty shocking," he said in a phone interview after the company recalled several of its venison foods. "I was livid."

Herrick declined to name the supplier of the rice protein or the country it came from, saying only that a large American company acquired the ingredient for Diamond Pet Foods, which makes some Natural Balance products.

Because both wheat gluten and rice protein enhance the protein content of pet food, "it certainly is suspicious" that melamine now is associated with both, said Bob Poppenga, a UC Davis veterinary toxicology professor.

Melamine isn't an edible protein, but it has plenty of nitrogen, which can be used as a marker for protein in chemical analyses.

So, if someone wanted to use less of the relatively pricey sources of vegetable protein, such as wheat gluten, and throw in cheaper starches instead, adding melamine to that mix would still make it look like a protein-rich product, numerous veterinary nutritionists and toxicologists have said. With such speculation swirling, the rice protein-melamine link further alarmed pet owners as it began appearing on Web sites Tuesday, said Gina Spadafori, a Sacramento-based author who runs a pet Web site.

"I see people who are being almost panicky," she said. "Last week, it was easy for veterinary associations to say if you want to feel better, just avoid wheat gluten," Spadafori said. "Now for this expansion to be an entirely different protein source ... I don't think right now anybody can say, 'Go feed this, it's safe.' "

Natural Balance President Herrick was so shaken by the melamine finding that he imposed a new policy Tuesday to hold all company foods in a warehouse until an offsite lab tests each batch for melamine. He won't ship anything until it has tested clean, he said.

Local veterinarians who've tracked kidney ailments nationwide have tentatively identified five more foods, not at this point under any recall, that they plan to have tested as soon as possible.

...The notion that melamine could be a deliberate additive -- not an industrial mistake -- arose as early as April 5, when Stephen Sundlof, head of the FDA's Center for Veterinary Medicine, said that the pet food recall could turn into a criminal investigation if investigators find that melamine was added deliberately.

Later, the New York Times reported that the Chinese company that supplied tainted wheat gluten to Menu Foods sought to buy large amounts of melamine through Internet trading sites.

...Amid complaints that the multiple recalls were hard to follow, the FDA tried to assemble all the recalled foods on a single list, now over 5,000 items long, on its Web site at www.accessdata.fda.gov/scripts/petfoodrecall/

As of Tuesday evening, the Natural Balance recalls hadn't appeared there. Natural Balance recalled two products Monday and added more Tuesday after learning of the melamine test results. It has pulled back Venison and Brown Rice canned and bagged dog foods, Venison and Brown Rice dog treats and Venison and Green Pea dry cat food.

For pet owners, vets said, the important thing to be aware of is any behavior change that seems linked to either a new food, or even a new bag of the same food. Symptoms could include loss of appetite, vomiting, lethargy and excess drinking or urinating.