The U.S. Food and Drug Administration (FDA) is expanding its investigation of jerky treats to now include duck and sweet potato jerky treats.

Ernie Ward, DVM, noted the update on his Facebook page.

"The FDA quietly updated their FAQ about potentially tainted jerky treats to include the following statement:

‘Has the agency received reports of illness associated with other types of jerky treats?

Yes. More recently (2012), the product-associated complaints have expanded to other jerky pet treat products such as duck and sweet potato jerky treats. Our investigation now includes these types of jerky treat products.’

An earlier story from NEWStat reported that the FDA is also investigating beef jerky treats manufactured by Del Monte Pet Products as well.

The FDA says it is still unable to determine a definitive cause of the illnesses, or link the illnesses to a particular company, from the samples collected.

The FDA had sent inspectors to Chinese plants that made the jerky treats.

On his Facebook page, Ward urged pet owners to stay away from dangerous treats.

"I continue to strongly advise you DO NOT feed your pet any of these types of treats MADE IN CHINA OR MEXICO," Ward posted on his Facebook wall.