Cornell Details Effect Of Pet Food Contaminant, Melamine

Smith also reported that Cornell had identified melamine in urine of affected cats and in the kidney of one cat that had died after eating the contaminated food. The deaths of 15 pets nationwide -- one dog and 14 cats -- have been confirmed by Menu Foods, the pet food maker. Veterinarians across the country have reported hundreds of cases of kidney failure in pets.

During the press conference, which was shown on CNN, Smith displayed photographs of the urinary tract crystals from affected animals that have been seen by clinicians and pathologists in many parts of the country, and he also showed a microscopic image of an affected kidney. However, Smith emphasized, Cornell researchers have not been able to match the known toxic effects of melamine with all of the clinical and pathologic signs observed in affected cats and dogs. He specifically referred to signs of acute damage to the tubules and the characteristic pattern of cellular inflammation that have been seen in affected kidneys.

Smith noted that Cornell has been playing a leading role in trying to identify the toxic properties of the contaminated food and in attempting to understand what might be causing the kidney failure. He also cited collaborations with other universities and private laboratories, including Advion, in Ithaca.

Menu Foods, the pet food maker for 95 top brands of "wet" pet foods, initially contacted Cornell's Animal Health Diagnostic Center to test pet food samples after six cats in one of their food trials died from kidney failure. On March 16, Menu Foods issued a massive recall of 60 million cans and pouches of pet food packaged from Dec. 3, 2006, to March 6, 2007.

At a press conference in Albany on March 23, researchers at the New York State Agriculture and Markets Food Laboratory reported they had found a toxin called aminopterin in two out of three pet food samples provided by Menu Foods. Smith participated in that press conference because the samples of pet food tested by the Albany laboratory had been supplied by Cornell researchers during an early phase of the investigation.

However, Smith and Stephen Sundlof, the FDA's chief veterinarian, noted at the Washington press conference that neither Cornell nor the FDA could confirm the presence of aminopterin in samples. Aminopterin, a derivative of folic acid, is sometimes used as a rodenticide, though such use is banned in the United States and Canada.

"Pets are part of the family structure," Smith told ABC News at the conclusion of the Washington, D.C., press conference. "I believe the answer is going to be a much broader look at both the safety of pet foods and the way we report illness [in our pets]."

Since March 30, at least four other pet food manufacturers have announced recalls of their respective products due to potential contamination. The FDA also has identified the supplier of the wheat gluten imported from China.