NEW YORK — Petco says it will stop selling dog and cat treats made in China by the end of this year due to ongoing fears that the imported treats are making pets sick.

The U.S. Food and Drug Administration hasn’t been able to identify why pets are getting ill. Since it launched an investigation late last year, the FDA said it received more than 4,800 complaints of pet illnesses and 1,000 dog deaths after eating Chinese-made chicken, duck or sweet potato jerky treats.

Petco, which operates 1,300 stores, says shoppers are asking it to stop selling the treats. The pet food retailer is switching them out for treats made in the U.S., New Zealand, Australia and South America.

Rival PetSmart Inc. didn’t immediately respond to a request for comment.