We have been urging pet owners not to feed their pets Chinese-made jerky treats, saying the treats can cause Falconi syndrome, a rare and often fatal illness that arises from kidney problems. Nearly 600 animal deaths and 3,600 cases of illness have been linked to the treats, but the FDA has yet to issue a recall.

According to the FDA, testing for contaminants in the jerky treats has not yet revealed a cause for the illness. Because the FDA cannot recall products without reason, the treats have remained on pet store shelves. The treats have been tested for dozens of harmful substances, but because they are hard and stiff, they are difficult to break down in solvents for chemical analysis.

For now, it is recommended that pet owners exercise caution and stop dolling out the treats.