Death toll for pets given jerky treats made in China rises to 600 and more than 3,600 dogs become ill as food agency struggles to pinpoint cause of mystery sickness



Kidney and urinary problems reported in dogs that were fed jerky

Food and Drug agency calls on vets to report new cases as scientists try to discover cause



Top brands voluntarily recalled products earlier in year

Nearly 600 pets have died and more than 3,600 have become sick in a mystery bout of illness being linked to jerky treats made in China.



Most cases have been dogs, but at least 10 cats have also been struck down with an illness that has confounded federal animal health officials.



Vets and pet owners are now being called on to report new cases as the Food and Drug Administration tries to pinpoint the cause of the sickness.

Concern: Waggin Train recalled its treats earlier this year after a rise in illnesses among pets given jerky

After eating the treats pets were said to have developed a range of symptons, from gastrointestinal illness to kidney or urinary troubles, according to NBC News .

' To date, testing for contaminants in jerky treats has not revealed a cause for the illnesses,' Martine Hartogensis, of FDA’s Center for Veterinary Medicine, said in the new report.



'Despite these warnings, we have continued to receive reports of illnesses in both cats and dogs,' she said.

After a spike in deaths and illness in January, the rate of new cases dropped, in part because the two major sellers of chicken jerky treats for pets voluntarily recalled their ranges.



At the time the recalls were said to relate to the presence of an antibiotic residue that was not approved in the U.S.



'All of us care deeply about pets and their owners, and the quality of our products is of the utmost importance,' company president Nina Leigh Krueger said in January.

She added that although the antibiotic residue was not deemed a health hazard, the company had voluntarily recalled its products while the investigation continued.



Among the products recalled were Nestle Purina PetCare Co’s Waggin Train and Canyon Creek Ranch treats, and Del Monte Corp’s Milo’s Kitchen Chicken Jerky and Chicken Grillers.



Recall: Leading brands including Milo's Kitchen and Canyon Ranch removed jerky from sale voluntarily

The FDA is still unsure as to what is causing the sicknesses and deaths, which have resulted in warnings about the possibility of Fanconi syndrome and other kidney problems.

'We still are extensively testing treats for a number of things ... but we still have a little bit of a way to go,' Ms Hartogensis said.

Veterinary clinical pathologist Kendal Harr , who has been tracking the problem, admitted experts were stumped.



'I think that what it tells us is that the intoxicant is something that we're not used to dealing with as a toxin in North America,' she said.

Vets have now been asked to send detailed information and blood and urine test results from any animals sickened by jerky treats.

About 60 per cent of cases cite gastrointestinal illness in the animals, and 30 per cent have kidney or urinary troubles, the report said. About 135 cases of Fanconi syndrome, a specific kind of kidney disease, were also reported.

Although officials warned pet owners to feed the treats in small quantities only the agency has not issued a recall yet.

Victim: The owners of this pug, Bella, who died from kidney failure, are campaigning for the FDA to do more to protect pets

Its response has angered some owners, who feel not enough is being done to safeguard their pets.



Robin Pierre, who blames Waggin' Train chicken jerky for the death from kidney failure of her two-year-old pug Bella, has been campaigning for the FDA to crackdown on manufactures.



' They need to start protecting the American consumer so that this does not happen again. As soon as a product is in doubt, a warning label should be placed at the point of sale so that consumers can make an educated choice,' she said.