Rat Poison Found in Tainted Pet Food

Tests turned up rat poison in the pet food suspected of causing kidney failure in dogs and cats across the country and killing at least 16, state officials and scientists announced Friday.

The toxin was identified as aminopterin, which is used to kill rats in some countries, state Agriculture Commissioner Patrick Hooker said. Aminopterin is not registered for killing rodents in the United States, though it is used as a cancer drug, according to the Environmental Protection Agency.

State officials did not say how they believe Aminopterin got into the now-recalled pet food, though they said no criminal investigations had been launched.

The Food and Drug Administration has said the investigation was focusing on wheat gluten in the pet food. Wheat gluten itself would not cause kidney failure, but the common ingredient could have been contaminated, the FDA said.

The pet deaths led to a recall of 60 million cans and pouches of pet food produced by Menu Foods and sold throughout North America under 95 brand names. There have been several reports of kidney failure in pets that ate the recalled brands, and the company has confirmed the deaths of 15 cats and one dog.

Menu Foods last week recalled "cuts and gravy" style dog and cat food. The recall sparked concern among pet owners across North America