Recall Now Includes Dry Pet Food

Government Finds Chemical, But No Rat Poison, In Tainted Pet Foods

(CBS/AP)  A massive North American pet food recall got even bigger Friday as Hill's Pet Nutrition recalled one of its brands of dry cat kibble for fear it contained melamine, the same toxin that forced Menu Foods to pull its wet "cuts and gravy" products from shelves across the continent.

The Food and Drug Administration said Friday it found melamine in samples of the Menu Foods pet food involved in the original recall and in imported wheat gluten used as an ingredient in the company's wet-style products. Cornell University scientists also found melamine in the urine of sick cats, as well as in the kidney of one cat that died after eating some of the recalled food.

Meanwhile, Hill's Pet Nutrition recalled its Prescription Diet m/d Feline dry cat food. The food included wheat gluten from the same supplier that Menu Foods used. The recall did not involve any other Prescription Diet or Science Diet products, said the company, a division of Colgate-Palmolive Co.

The FDA was working to rule out the possibility that the contaminated wheat gluten could have made it into any human food. However, melamine is toxic only in high doses, experts said, leaving its role in the pet deaths unclear.

Emergency vet Dr. Benjamin Davidson says melamine is hardly a smoking gun.

"We know the compound is present, but there is no cause-and-effect relationship. We don't know that 'Yes, this is the compound that is definitely causing the renal disease,'" Davidson told CBS News correspondent Sharyn Alfonsi.

Menu Foods recalled 60 million containers of cat and dog food, sold throughout North America under nearly 100 brands, 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 company, more than 300,000.

Company officials on Friday would not provide updated numbers of pets sickened or killed by its contaminated product. Pet owners would be compensated for veterinary bills and the deaths of any dogs and cats linked to his company's products, the company said.

The melamine finding came a week after scientists at the New York State Food Laboratory identified a cancer drug and rat poison called aminopterin as the likely culprit in the pet food. But the FDA said it could not confirm that finding, nor have researchers at the University of Medicine and Dentistry of New Jersey when they looked at tissue samples taken from dead cats. And experts at the University of Guelph detected aminopterin in some samples of the recalled pet food, but only in the parts per billion or trillion range.

"Biologically, that means nothing. It wouldn't do anything," said Grant Maxie, a veterinary pathologist at the Canadian university. "This is a puzzle."

Meanwhile, New York officials stuck to their aminopterin finding and pointed out that it was unlikely that melamine could have poisoned any of the animals thought to have died after eating the contaminated pet food. Melamine is used to make plastic kitchen ware and is used as a fertilizer in Asia.

An FDA official allowed that it was not immediately clear whether the melamine was the culprit. The agency's investigation continues, said Stephen F. Sundlof, director of the FDA's Center for Veterinary Medicine.

In a news conference, Sundlof and other FDA officials said the melamine had contaminated a shipment of wheat gluten imported from China and purchased by Menu Foods from an undisclosed supplier in the United States. At least some of the that wheat gluten was used in all the recalled wet pet food, according to Menu Foods.

Menu Foods said the only certainty was the imported Chinese product was the likely source of the deadly contamination, even if the actual contaminant remained in doubt.

"The important point today is that the source of the adulteration has been identified and removed from our system," said Paul Henderson, Menu Foods chief executive officer and president. Henderson suggested his company would pursue legal action against the supplier.

New York remained confident in its aminopterin finding, said Patrick Hooker, commissioner of the state Department of Agriculture and Markets. Hooker added that neither aminopterin nor melamine should be in pet food, but that it was unclear why the latter substance would be poisonous to the cats in which it was found.

"While we have no doubt that melamine is present in the recalled pet food, there is not enough known data on the mammalian toxicity levels of melamine to conclude it could cause illness and deaths in cats. With little existing data, many questions still remain as to the connection between the illnesses and what has caused them," Hooker said.

Wheat gluten, a source of vegetable protein, is also used in some human foods, but the FDA emphasized it had found no indication that the contaminated ingredient had been used in food for people. The FDA said it would alert the public quickly if the melamine was found in any foods other than the recalled pet food.

About 70 percent of the wheat gluten used in the United States for human and pet food is imported from the European Union and Asia, according to the Pet Food Institute, an industry group. Menu Foods used wheat gluten to thicken the gravy of its "cuts and gravy" style wet pet foods, FDA officials have said.

One veterinarian suggested the international sourcing of ingredients would force the U.S. "to come to grips with a reality we had not appreciated."

"When you change from getting an ingredient from the supplier down the road to a supplier from around the globe, maybe the methods and practices that were effective in one situation need to be changed," said Tony Buffington, a professor of veterinary clinical sciences at Ohio State University.

The FDA's Sundlof said the agency may change how it regulates the pet food industry.

"In this case, we're going to have to look at this after the dust settles and determine if there is something from a regulatory standpoint that we could have done differently to prevent this incident from occurring," he said.