Recalled pet foods contained a chemical used to make plastics, but government tests failed to confirm the presence of rat poison, federal officials said Friday.
The Food and Drug Administration said it found melamine in samples of the Menu Foods pet food, as well as in wheat gluten used as an ingredient. Cornell University scientists also have found the chemical, also used as a fertilizer, in the urine of sick cats, as well as in the kidney of one cat that died after eating the company's wet food.
Menu Foods recalled 60 million containers of cat and dog food earlier this month after animals died of kidney failure after eating the Canadian company's products. It is not clear how many pets may have been poisoned by the apparently contaminated food, although anecdotal reports suggest hundreds if not thousands have died. The FDA alone has received more than 8,000 complaints.
The new finding comes a week after scientists at the New York State Food Laboratory identified a rat poison and cancer drug called aminopterin as the likely culprit. The FDA said it could not confirm that finding.
New York officials have detected melamine as well, though it's not clear how that chemical would have poisoned pets. It's typically used to produce plastic kitchen wares, though it's apparently used as a fertilizer in Asia, said Stephen F. Sundlof, director of the FDA's Center for Veterinary Medicine.
The recall involved nearly 100 brands of "cuts and gravy" style dog and cat food made by Menu Foods. The recall covered products carrying names of major brand-name and private-label products sold throughout North America.
The apparently melamine-contaminated wheat gluten also was shipped to an unnamed company that manufactures dry pet food. The FDA is attempting to determine if that product, imported from China, was used to make any pet food, Sundlof said.