Two of the nation’s top retailers of chicken jerky dog treats are voluntarily withdrawing several popular brands after New York state agriculture officials said they may be contaminated with unapproved antibiotics.

Nestle Purina PetCare Co. officials announced Wednesday that they’re withdrawing Waggin’ Train and Canyon Creek Ranch brand dog treats until further notice. Officials at Milo’s Kitchen, which is owned by the Del Monte Corp. of San Francisco, announced they are voluntarily recalling the firm's Chicken Jerky and Chicken Grillers home-style dog treats from shelves nationwide.

The move came after the New York Department of Agriculture and Marketing told federal Food and Drug Administration veterinary officials this week that trace amounts of residual poultry antibiotics had been found in several lots of each of the brands of jerky treat products.

The agriculture agency found very low levels of four antibiotics that are not approved for use in poultry in the U.S. and one antibiotic that is approved for U.S. poultry use, but is limited to nearly undetectable levels in the finished product, said Joe Morrissey, a department spokesman. The antibiotics include sulfaclozine, tilmicosin, trimethoprim, enrofloxacin and sulfaquinoxaline, he said.

The antibiotics are approved in China, where most of the treats are made, and in other countries, according to company statements. 

However, Keith Schopp, a spokesman for St. Louis-based Nestle Purina, said that the issue is not related to the ongoing FDA investigation of problems with Chinese-made jerky pet treats that may have sickened more than 2,200 pets and killed 360 dogs and one cat, according to consumer reports.

"There is no indication that the trace amounts of antibiotic residue is related to FDA's ongoing investigation," Schopp told NBC News. 

"Due to regulatory inconsistencies among countries, the presence of antibiotic residue is technically considered an adulteration in the United States," Schopp added.

FDA officials said they were confident that the detection of antibiotics "do not raise health concerns," and that they are "highly unlikely" to be related to the reports of pet illness linked to jerky treats that date back to 2007, according to a statement published late Wednesday.

FDA has conducted extensive testing and said it could find no toxins or other contaminants responsible for causing alleged illnesses ranging from nausea and vomiting to kidney failure and death. Officials said that the New York agriculture agency used a new, particularly sensitive test to detect the antibiotics. Morrissey said food specialists there tested the jerky treats because of "growing consumer concerns."

FDA officials reminded pet owners that jerky treats are not a necessary part of any animal's diet.

Robin Pierre, a New York pet owner, blames Waggin' Train chicken jerky treats for the sudden death of Bella, her 2-year-old pug in 2011. Pierre, who launched a petition urging companies to recall the treats, said she was pleased at the new move, but sorry that the FDA didn't act sooner.

"How many lives could have been saved if, six years ago, when there was first doubt that the safety of our companions was compromised, the FDA and all manufacturers of imported chicken jerky had issued a precautionary recall until the toxin was found?" she said in a statement to NBC News. "How much pain and suffering could have been avoided if only they had met their moral obligation six years ago and did the job the taxpayers pay them to do?"

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