WASHINGTON – The Food and Drug Administration is reaching out pet owners for help as the agency works to discover why jerky treats are causing illness and death among the nation's pet population.

Since 2007, FDA has received reports of pet treat-related illnesses involving 3,600 dogs and 10 cats. Approximately 580 of those pets have died. The FDA's Center for Veterinary Medicine has conducted more than 1,200 tests and visited jerky treat manufacturers in China that were implicated in the illnesses. Despite the investigations and collaborations with academia, industry and state laboratories, the agency has failed to pinpoint the exact cause of the illnesses.

"This is one of the most elusive and mysterious outbreaks we've encountered," said CVM Director Bernadette Dunham, DVM, Ph.D. "Our beloved four-legged companions deserve our best effort, and we are giving it."

To aid in the agency's investigation, FDA is reaching out to pet owners and veterinarians across the country. In a letter to veterinarians, the agency details what information is needed for labs testing pet treats and investigating causes of illness or death. This may include blood, urine and tissue samples. FDA will request written permission from pet owners to collect the samples and will cover costs, including shipping, associated with the tests.

FDA also will include a consumer fact sheet to help veterinarians communicate the problem to consumers and remind that treats are not essential to their pets' diet. The agency is encouraging consumers to report illnesses related to pet jerky treats online or by calling the FDA Consumer Complaint Coordinator in their state.

The treats are sold as jerky tenders or strips made of chicken, duck, sweet potatoes and/or dried fruit. Some pets exhibited symptoms within hours of eating the treats -- decreased appetite, decreased activity, vomiting, diarrhea (sometimes with blood or mucus), increased water consumption, and/or increased urination. Severe cases have involved kidney failure, gastrointestinal bleeding, and a rare kidney disorder. Other reported symptoms included collapse, convulsions or skin problems.

FDA noted that most of the jerky treats implicated in the illnesses were made in China. Inspections of facilities associated with some of the highest numbers of pet illness reports failed to uncover the cause of illness. However, investigators did turn their attention to the supply chain of some ingredients in the treats. FDA said inspectors found that one firm falsified receiving documents for glycerin, a jerky ingredient. Chinese authorities seized the products at the firm and suspended its exports.

Pet food manufacturers are not required by US law to state the country of origin for each ingredient in their products, FDA said.