

The problem appears to be tied to dog pet treats made in China, the FDA said, though investigators haven't yet found a certain cause. The FDA says it has received reports of illnesses in 3,600 dogs and 10 cats in the United States since 2007, and 580 dogs died. The pet treats were sold under a wide variety of brand names.

The complaints were sent in by pet owners, some of them unsure of the cause of their pet's illness. But many others were sent in by veterinarians who have seen repeated cases of kidney failure, gastrointestinal bleeding, and a rare kidney disorder, the FDA said.


"This has been one of the most mysterious and elusive issues we've had to investigate," Hartogensis said.


She said the investigation has been particularly complicated because researchers haven't been able to pin down what ingredient may be causing the problem and because many of the treats and their ingredients are imported. And not much is known about animal deaths. While autopsies on humans can often determine the cause of death, pet owners usually forgo expensive autopsies on their deceased animals.



He said most dogs he treated were fine if they stop eating the treats. That's why it's important for dog owners to know about the problem, he said.

"The word is not out," he said. "Some vets don't even know about this."



But others remain on store shelves, and FDA doesn't want to conduct a recall without a definitive cause.



In one comment sent to the agency this year, a dog owner whose name was withheld by the FDA wrote that their pet started vomiting and became lethargic and thirsty after eating a chicken jerky treat. The next morning the dog couldn't walk and the owner was told by a vet that there was total renal failure. The dog died that night.

"They said there were many dogs who had died from eating these treats and my vet had treated many sick animals," the dog owner wrote in documents released by the FDA. "They posted warnings about these treats all over their office and exam rooms."

