Salmonella has been found in some raw dog food products, according to the U.S. Food and Drug Administration (FDA).

Three lots of Darwin’s Natural Pet Products tested positive for the bacterium, the agency said in a release Tuesday. The products, manufactured by Arrow Reliance, Inc., are sold online directly to consumers.

The department found the contamination in response to a consumer complaint. The FDA responded to the complaint by analyzing unopened samples of the product from the three lots.

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The FDA is warning pet owners against feeding their dogs from the contaminated lots, because they “represent a serious threat to human and animal health.”

The affected lots, according to the FDA are: “Natural Selections Turkey Recipe with Organic Vegetables for Dogs,” manufactured on Oct. 26, 2018 with the code 5339(11)181026 and two lots of “Natural Selections Chicken Recipe with Organic Vegetables for Dogs,” manufactured on Oct. 19, 2018 with the code 5309(11)181019 and on Nov. 6, 2018 with the code 5375(11)181106.

The FDA recommends anyone who has purchased these lots throw them away in a manner that prevents pets or other animals from accessing it.

The agency also suggests thoroughly cleaning all surfaces, containers or items that may have come into contact with the products or pets that have consumed the products.

Salmonella can cause illness and even death in humans and animals, particularly for those with weak immune systems or are very young or very old, the FDA warned. People who have been infected can develop diarrhea, fever and abdominal cramps, according to the Centers for Disease Control and Prevention (CDC).

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The FDA warned that pets may not always display symptoms of Salmonella infection, but some signs in pets include vomiting, diarrhea, fever, loss of appetite or decreased activity levels. Pets can also pass Salmonella in their feces even if they don’t show symptoms of the infection.

Arrow Reliance has removed the products from the market but did not issue a public recall notice. The agency is still working with the firm to recall the remaining products.

“The FDA is not confident that the firm’s customer notifications are effective for this ongoing recall,” the agency said in its statement. The department said it is concerned people may still have the products in their possession because they are sold and stored frozen.