Federal health regulators quietly flexed new food safety muscles last week when they threatened a Denver pet treat maker with the Food and Drug Administration’s first mandatory recall of potentially tainted products.

Kasel Associated Industries pulled all pet treats manufactured at the Colorado facility from April 20, 2012 to Sept. 19, 2012 because the products -- ranging from pig ears and salmon jerky to buffalo hearts and dried bull penises -- may have been contaminated with salmonella.

The move was the third recall since September of Kasel products, and it came only after the company originally refused to voluntarily recall products. In December, FDA officials issued a warning advising consumers to avoid the products.

But inspections in September revealed significant problems with salmonella contamination, including tests that showed that 48 of 87 swabs of the plant’s environment turned up the bacteria that can cause illness in pets and humans.

In addition, there were documented problems with rodents and insects, including larvae, flies, worms, beetles and “cockroach-like” insects, according to FDA inspection reports.

As the conclusion of a second inspection on Feb. 14, FDA officials issued a final notice to Kasel to cease distribution and conduct a voluntary recall before the agency took mandatory action.

Such hearings -- and the mandatory recall authority -- are part of the 2011 Food Safety Modernization Act, which grants sweeping new authority to regulate producers.

FDA officials said they have received “a small number’’ of complaints of illness in dogs who were exposed to the treats. Salmonella infection can be transmitted to humans who come in contact with the treats or pets who’ve consumed them, but FDA has received no reports of human infections.

The Kasel treats are sold by various big-name retailers, including Target, Petco, Sam’s Club and Costco.

The recall of the U.S.-made treats is not related to the FDA’s ongoing investigation of illnesses and deaths in dogs and cats exposed to chicken jerky pet treats made in China.

Pet health advocates have clamored for the FDA to use the FSMA authority to force mandatory recall of the foreign-made treats, which have been blamed for deaths of 500 dogs and nine cats, and illnesses involving 3,243 dogs at last count.

Jalil Isa, an FDA spokesman, said that the Kasel recall involved a “reasonable probability” that the Colorado-made pet treats were adulterated.

“The FDA continues to investigate jerky pet treats from China, along with its partners in the Veterinary Laboratory Response Network,” Isa said in an email.

In the meantime, several varieties of chicken jerky pet treats made in China, have been recalled from store shelves after New York agriculture officials detected unapproved antibiotics in the products.

Nestle Purine PetCare Co. recalled its popular Waggin’ Train and Canyon Creek Ranch brand dog treats, and Del Monte Corp. officials recalled their Milo’s Kitchen Chicken Jerky and Chicken Grillers home-style dog treats from shelves nationwide.

In addition, Publix stores recalled private Chicken Tenders Dog Chew Treats and IMS Pet Industries Inc. withdrew its Cadet Brand Chicken Jerky Treats sold in the U.S.

Related stories:

• More recalls of US-made pet treats
• 3 big brands may be tied to chicken jerky illness in dogs, FDA records show
• China stiff-arms FDA on jerky pet treat testing, reports show