Concerned dog owners who have quit buying jerky treats made in China should be wary of those made in the United States as well.

Even treats manufactured in the country could contain ingredients sourced in China, according to the U.S. Food and Drug Administration.

"Manufacturers do not need to list the country of origin for each ingredient used in their products," Martine Hartogensis, supervisory veterinary medical officer for the FDA’s Office of Surveillance and Compliance, said in a news release.

Since 2007, the FDA has received nearly 5,000 complaints of illness related to jerky treats made in China, and more than 1,000 U.S. dogs have died.

The government agency has been investigating the complaints, but no specific toxin has been identified and tests haven't confirmed any connection between the treats and the thousands of cases reported in U.S. cats and dogs.

Both Petco and PetSmart removed Chinese-made treats from their shelves earlier this year, but the treats are still widely available.

All of Petco's treats are now made in the U.S. or in places such as the Netherlands, New Zealand, Australia or South America. However, even treats with a "Made in the USA" label can legally contain ingredients from outside the country.

According to the Federal Trade Commission, which oversees made-in-USA claims, products that feature the label must simply meet the all-or-virtually-all standard, meaning that all significant parts and processing that go into a product must be of U.S. origin. In fact, "... if ingredients are imported, then it is very difficult to justify the use of the phrase 'Made in the USA,'" according to the Association of American Feed Controls, which develops industry guidelines for pet food.

What to do if you feed your pet jerky products

The FDA advises not to substitute treats for food in general and cautions owners of cats and small dogs to be especially careful in limiting the amounts they consume. Adhere to weight guidelines on the product's packaging.

Stop feeding your pet the treats if the animal shows any of the following signs, which could occur within hours to days after ingestion: decreased appetite, decreased activity, vomiting, diarrhea, increased water drinking or urination.

If symptoms are severe or last more than 24 hours, contact your veterinarian and report the illness to the FDA Consumer Complaint Coordinator in your area.

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