The Food and Drug Administration has issued a warning to pet owners about chicken jerky dog treats after 600 dogs reportedly got sick or died after eating the treats.

Channel 11 News worked with MSNBC on uncovering the danger.  According to internal Food and Drug Administration documents, three dog threat brands have received the most complaints.

They're made in China and may be linked to mysterious canine illnesses, including kidney failure and even death, yet the FDA can't find anything wrong with the treats.

Sarah Lipton came home from work one day and found her 3-month-old puppy Riley lying listless in his playpen.

She went online trying to find out what was wrong, and stumbled on a warning about chicken jerky treats.

"My dog treats, 90 percent of them were made in China. That's exactly what they were talking about online," said Lipton.

She stopped feeding him the treats and within a few days Riley was better.

"I felt it was a very close call," said Lipton.

The FDA is investigating 600 reports of dogs getting sick or even dying after eating chicken jerky treats made in China.

Internal documents obtained by MSNBC showed three popular brands may be associated with kidney failure and other serious illnesses.

They're Waggin' Train and Canyon Creek Ranch jerky treats or tenders by Nestle Purina, and Milo's Kitchen Home-Style Dog Treats by Del Monte.

The manufacturers insist their products are safe saying tests have failed to show any "definitive cause or connection between the illnesses and the treats," which are meant to be fed in small quantities.

The FDA has tested these brands along with several others and cannot find any dangerous toxins so they issued a cautionary warning, but nothing has been recalled.

"If they're making that many dogs sick and dogs are dying and there's vets that have that information, I don't understand why they're not being pull off the shelf," said Lipton.

"I wouldn't buy them, let along feed them.  If you have some at home, I would take them back, get a refund," said Dr. James Krewatch, a veterinarian with Bradford Hills Veterinary Hospital.

Dr. Krewatch told me dogs with kidney problems aren't eating, they have no energy and may even vomit or have diarrhea.

According to the FDA these symptoms can happen within hours or days of eating the treats. But what's causing it?  

"Some of these things just are not easy to uncover," said Dr. Krewatch.

FDA documents suggest it may not be the chicken treats alone.

"It may be one food or one ingredient mixing with a totally different ingredient, that normally weren't together that causes a problem," said Dr. Krewatch.

As for Sarah, she's making her own dog treats until this mystery is resolved.

"I have two dogs and I don't want to lose either one of them, they're our family," said Lipton.

There are plenty of other dog treats that are not made in China.  I would look at the labels carefully before buying anything.