Federal authorities have notified a Berks County, Penn. raw-pet food producer that its dog food has been found to contain salmonella.

A U.S. Food and Drug Administration “warning letter” sent last month to Lystn LLC, dba Answers Pet Food at 356 Maidencreek Road in Richmond Township, says the company’s Detailed Answers Chicken Formula dog food showed traces of salmonella.

The FDA letter says investigators found salmonella in its Detailed Answers Chicken, 8-ounce raw chicken patties and the 2-pound carton Detailed Answers Chicken Formula.

In a news release issued Wednesday and subsequent telephone interview, Lystn officials denied the company is introducing salmonella in its pet food or allowing product in the market “that could result in illness to animals or humans.”

Company officials also say they believe they have addressed the FDA’s concerns about its food processing and contend the agency has denied to address the company’s follow-up questions.

The U.S. Department of Agriculture allows a limited amount of salmonella in poultry and other food consumed by humans, said Jacqueline C. Hill, the company’s vice president of operations, product development and sales.

“But we’re not regulated by the USDA but by the FDA, and it says pet food can’t contain any salmonella,” Hill said. “We’re a small family company trying to make dogs and cats healthier.”

Lystn began selling raw pet food in 2010, said Hill, adding there are many advantages to feeding it to domestic animals, including helping to heal those with chronic health issues.