A toxin used for rat poison has been found in tainted pet food that has killed at least 14 animals and fired panic among dog and cat owners in the United States and Canada, US officials said Friday.
The New York state laboratory working with scientists from Cornell University identified the toxin, which is banned in the United States, in samples of the pet food from Canadian manufacturer Menu Foods.
And an unconfirmed US media report said that the toxin had been found in wheat imported from China that was used in preparing the pet food.
The toxin, called aminopterin, can cause cancers and birth defects in humans and kidney damage in cats and dogs.
"We are pleased that the expertise of our New York State Food Laboratory was able to contribute to identifying the agent that caused numerous illnesses and deaths in dogs and cats across the nation," New York state agriculture commissioner Patrick Hooker said in a statement.
Last week the Menu Foods recalled 60 million cans and pouches of food made in the United States and sold in 95 different brands.
On Friday, the Toronto-based company said it didn't know where the toxin came from, but said it would compensate US and Canadian owners of animals that died or became ill from its products.
"To the extent that we identify that the cause of any expenses incurred are related to the food, Menu will take responsibility for that," said Menu Foods President Paul Henderson.
"How did this substance get in to our products? At this stage, we don't know," Henderson told reporters.
"The probability of tampering is considered remote," he added.
Several people have filed suit in US courts as well as in Canada following the deaths of their pets.
A couple in the US state of Arkansas have sued over costs incurred in the illness and death of their dog Abby, and in Wisconsin a woman filed a complaint concerning her cat Gumbi, who will require life-long treatment following kidney failure caused by pet food.
According to Stephen Sundlof, who leads the US Food and Drug Administration's veterinary medicine center, at least 14 pets have died from the tainted food.
It is "too early for us too tell," Sundlof told AFP. "We are still evaluating the numbers."
He said the FDA has received 4,400 calls in the past few days from concerned pet-owners.
Sundlof said the FDA did not yet know how the toxin got into the food.
"We don't know where it comes from. We haven't ruled out sabotage, in fact we don't have any theory," he said.
However, he did say the FDA is investigating the supplier of wheat gluten that went into the pet food.
Earlier Friday, ABC television reported that the toxin had been found in wheat imported from China used in the pet food.
"A source close to the investigation tells ABC News that the rodenticide ... was on wheat that was imported from China and used by Menu Foods in nearly 100 brands of dog and cat food," the US network said on its website.
Henderson identified two manufacturing plants in Kansas and New Jersey linked to the spoiled pet foods, and said a review of its operations and testing of the recalled foods is underway.
"Our hearts and sympathies go out," Henderson told reporters.
"A pet is an important part of every family ... We are heartfelt and heart stricken by the fact that anybody has suffered anything or experienced any loss as a result of these events," he said.
