Chinese-made dog treats made of chicken jerky sickened 353 pets in 2011, and the Food and Drug Administration has issued a warning on the animal snacks.
Dog owners report symptoms including kidney failure and low blood sugar within hours or days of consumption of the jerky.
The FDA is studying the products, and so far has not isolated the problem.
The agency is “still digging through the reports to see if we can discern a common thread that’s more specific than just chicken jerky,” said spokeswoman Siobhan DeLancey.
The FDA released its first warning on the products in 2007, when it recorded 156 complaints about the jerky. Complaints fell to 41 in 2008.
Officials recommend that pet owners avoid the treats and seek medical care for dogs that experience continued lowered appetite or activity, diarrhea, vomiting, or increased urination or water consumption after eating such products.