Tainted pet food brings questions by consumers
Extent of damage to animals still not known; United Nations tests show small risk to humans
By Andrew Bridges
Associated Press

WASHINGTON - First, cats and dogs were sickened and died after they ate pet food contaminated with an industrial chemical. Then, it was disclosed that hogs were fed the same pet food, raising concerns that the chemical had entered the human food supply.

Some questions and answers about the contamination, the massive recall that followed and the risks to people and animals:

Q: What chemical tainted the food?

A: Traces of melamine, a nitrogen-rich chemical used in a variety of industrial processes, were found in the pet food. Its most common use is to make resins, which in turn can be molded into products like countertops and kitchen utensils, including plastic dinnerware sold as Melmac.

Q: Is melamine toxic to animals?

A: Melamine appears to have caused acute kidney failure in animals that have died or been sickened after eating foods laced with the chemical. Previously, the only known risk was to rodents. When fed to male rats in high doses, melamine indirectly caused tumors by forming stones that irritated the lining of the bladder, according to a 2002 United Nations environmental report. The report concluded its toxicity to mammals is low.

Q: How many pets have died after eating contaminated food?

A: No one knows. Estimates run from a few dozen to several thousand dogs and cats. The FDA has confirmed only about 15 pet deaths.

Q: What about people?

Q: Has melamine been found in any human foods?

A: No. However, the FDA is beginning to test wheat gluten, rice protein concentrate and at least four other vegetable proteins imported for use by firms that make human food, including pizza dough and infant formula, and those that manufacture animal feed.

Q: What's the connection to human food?

A: State and federal investigators are looking at hog farms in Ohio and at least five other states that were supplied with salvaged pet food distributed before it was known to be contaminated with melamine. It wasn't immediately clear which farms had hogs that actually ate the contaminated pet food.

Q: How many brands of pet food were recalled?

A: Companies have recalled more than 5,500 varieties of pet food and treats, sold under more than 100 brands.

Q: What advice has FDA given pet owners?

A: The agency recommends checking if a pet's food has been recalled. Any recalled food should not be used. A complete, searchable list is available on the FDA's Web site: www.fda.gov. If a pet suffers a loss of appetite, lethargy or vomiting, the FDA suggests owners contact a veterinarian.

Q: How did the melamine get into the pet food in the first place?

A: Two vegetable proteins tainted with melamine were imported from China and used in pet foods sold in North America, while a third was used in southern Africa. In the United States, melamine has shown up in wheat gluten and rice protein concentrate. The protein-rich ingredients were used to produce the now-recalled brands of pet foods and treats by U.S. and Canadian companies.

Q: Who imported the tainted ingredients and where did they go?

A: All three vegetable proteins tainted with melamine were imported from China. Two companies are known to have imported tainted ingredients: ChemNutra Inc. of Las Vegas bought wheat gluten, and Wilbur-Ellis Co. of San Francisco purchased the rice protein concentrate. Both companies in turn sold the wheat gluten and rice protein concentrate to pet food manufacturers or distributors that supply such companies. The FDA does not believe either ingredient went directly to any company that used them to make human food.