One dog died and others became ill after eating canned food contaminated with pentobarbital.

Joel Sher, the vice president of Illinois-based Evanger’s Dog and Cat Food Company, which his family owns, said a now-former supplier apparently sent his company beef from at least one cow that had been euthanized with pentobarbital. Five Pugs in Washington state showed signs of acute neurologic illness and one of them died after sharing a can of Hunk of Beef Au Jus in late December 2016, leading to a Food and Drug Administration investigation and voluntary recalls for three products in February and March.

FDA information indicates pentobarbital was detected through tests on the contents of the dead dog’s stomach and unopened cans of the Evanger’s food. The agency also tested another variety of dog food.

“In the course of the investigation, the FDA tested two cans of Against the Grain brand canned Grain Free Pulled Beef with Gravy dog food manufactured in the same facilities as Evanger’s products and using beef from the same supplier: these samples also tested positive for pentobarbital,” FDA information states.

So far this year, the agency has received five complaints, including the Washington report, suggestive of pentobarbital poisoning connected with Evanger's foods. Four were connected with neurologic signs and one with hepatic signs.

FDA officials were investigating four of the complaints using available dog food and veterinary medical records.

No illnesses have been reported in connection with the Against the Grain product.

Sher said he had no way to know his company’s dog food could be contaminated with pentobarbital or that the company should test for its presence.

“We might as well test for radioactivity,” he said.

He said that, while Evanger’s is being held responsible for the contamination, he wants to see regulatory changes that would increase meat suppliers’ responsibility for preventing contamination of animal foods with pentobarbital and other euthanasia chemicals.

He wants federal requirements for clear markings on animal carcasses following euthanasia. He also wants a prohibition on use of those carcasses in any animal foods.

The FDA investigation into the poisonings continued in early March. Because Evanger's is a contract manufacturer for other companies, the agency was trying to determine whether other products were affected.

Agency statements indicate FDA officials have concluded the meat supplier had systems in place to ensure euthanized animals were segregated from carcasses intended for animal food use, and one of the statements notes that salvage facilities that collect animal carcasses also are responsible for segregating carcasses after determining how the animals died. Because pentobarbital residues are unaffected by rendering or canning temperatures and pressures, animals killed with chemical euthanasia substances, including pentobarbital, cannot be used in the manufacture of pet foods.

“There is currently no set tolerance for pentobarbital in pet food and detection of its presence renders the product adulterated,” FDA officials said in one statement.

The FDA also is implementing rules under the Food Safety Modernization Act that will require that manufacturers implement food safety plans, hazard analysis, and hazard minimization controls. The largest firms will need to meet those standards by September 2017, and the smallest by September 2019.

The FDA also published in February a series of observations by inspectors who visited the two Illinois manufacturing plants that produced the recalled products. They include allegations of condensation dripping into open cans of dog food, mold on walls, lack of temperature control, raw meat prepared on unsanitary concrete floors and lumber, and bird infestations. Sher said he had been told he would have more time to respond to the allegations before they were made public, that some of them were untrue or made without full knowledge of the operation, and that the FDA will need to justify any errors published.

The observations in the report do not represent a final determination of whether Evanger’s is complying with laws and regulations, an agency response states. But the agency can publish observation forms when requested or when it anticipates it would receive requests, with redactions to protect confidential information.

The recall affects 12-ounce cans of Evanger's Hunk of Beef with barcodes ending in 20109, Evanger's Braised Beef with barcodes ending in 20107, and Against the Grain Pulled Beef with barcodes ending in 80001. All have expiration dates between December 2019 and January 2021.