Fertilizer chemical found in recalled pet food

NEW YORK (Reuters) -- U.S. officials said Friday that melamine, a chemical found in fertilizers in Asia and which should not be in pet food in any amounts, has been detected in the wheat gluten used by Canada-based Menu Foods .

The FDA said the wheat gluten in question came from a company in China, and was not known to be used in any human food yet.

Video More video Pet owners what the company who manufactured tainted pet food to pay. CNN's Chris Lawrence reports. (March 30) Play video

U.S. Food and Drug Administration official Stephen Sundlof said during a press conference that melamine was found in the urine of dead cats. Though its presence is undeniable, it has not been determined to cause sickness or deaths in pets, he said.

Melamine should not be in pet food in any amounts, Sundlof added.

Last week, New York state officials said aminopterin, a substance used in rat poison, was found in the tainted pet food. Aminopterin is forbidden for use in the United States since it is known to cause kidney failure in cats and dogs. It is also known to cause cancer and birth defects in humans.

The FDA, however, has still not confirmed the presence of that toxin in the recalled pet food, the agency said Friday.

Menu Foods (down $0.20 to $3.30, Charts) has recalled millions of pounds of wet pet food in the past two weeks after it was associated with kidney failure in pets and deaths of at least 14 animals.

The recalled pet food is packaged under a wide variety of brand names and sold at a number of retailers including Kroger (up $0.16 to $28.15, Charts), Safeway (down $0.06 to $36.55, Charts), Wal-Mart (up $0.02 to $46.74, Charts), and at specialty pet stores like PetSmart (up $0.08 to $32.81, Charts) and Pet Valu (up $0.00 to $75.73, Charts).

Rat poison found in recalled pet food

Pet food maker expands recall push