Robert Barker/University Photography

College of Veterinary Medicine Dean Donald Smith talks with Tracy Egan, a reporter with WTEN-TV in Albany, following the March 23 press conference at the New York State Department of Agriculture and Markets' offices.

Cornell's Animal Health Diagnostic Center (AHDC) is conducting further tests on pet food that may have caused fatal kidney failure in 15 cats and one dog as it seeks to confirm the presence of a toxic compound called aminopterin in samples and to determine if other toxic substances may be present.

The new tests follow a press conference in Albany on March 23 at which researchers from the New York State Department of Agriculture and Markets Food Laboratory reported that they had identified aminopterin in samples of the pet food.

Cornell is also testing such individual ingredients as wheat gluten used to thicken the "cuts and gravy" style dog and cat food that has been recalled. Wheat gluten from China is currently the suspected source of contamination.

"Our Cornell team continues to work with state agriculture and markets scientists, with the FDA [U.S. Food and Drug Administration] and with scientists in laboratories across the country in pursuing this problem to its full conclusion," said Donald Smith, dean of Cornell's College of Veterinary Medicine, who attended the press conference.

Menu Foods, the pet food maker for 95 top brands of pet foods, had initially contacted Cornell's AHDC in mid-March 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. Although Cornell ran hundreds of tests on the samples, the results were inconclusive.

The samples were then sent to the state's food laboratory for further testing. While both the state's food laboratory and the AHDC are part of the country's Homeland Security initiative to keep the country's animals and food supply safe, the state's laboratory includes special equipment and methods for identifying unusual chemicals. State toxicologists said that they had identified significant levels of aminopterin in two out of three samples of the pet food.

Aminopterin, related to folic acid, is used in some countries as a rodenticide, although it illegal for such use in the United States and Canada. However, it has been used sparingly for cancer research in this country.

Cornell is also investigating whether aminopterin or other substances might induce the type of kidney failure that killed the affected cats and how best to treat affected animals once the toxic agent or agents are confirmed.

Update, March 30: CU scientists identify melamine in recalled pet food and affected cats.