An executive at pet food company Evanger’s, which recently recalled its own and Against the Grain beef canned dog food due to drug contamination, recently admitted to a Washington state newspaper that the recalled food contained horse DNA. The company has thus far blamed these issues on its meat supplier, but this is not the first time Evanger’s pet food has included an animal meat that wasn’t advertised.

This week, the woman who discovered the contamination spoke to her local newspaper, telling the story of what happened. Her four pugs immediately became ill, and one died in veterinary intensive care.

The paper also interviewed Michael Sher, company vice-president and part of the family that owns Evanger’s.

“We don’t have pentobarbital in our plant,” he told The Columbian. “We don’t have any poisons in our plant.”

However, he explained that analysis showed that the drug was in the food, and the company found cattle and horse DNA when testing the food. The company blames its meat supplier (still unnamed) and, confusingly, the FDA.

“We have taken it upon ourselves to lead the campaign to force the FDA to put an end to allowing drugs like pentobarbital to enter the raw material stream and contaminate our pets’ food and endanger their lives,” Evanger’s says on its recall update page.

The FDA allows no such thing, explaining in its statement about the contaminated Evanger’s food that “[pentobarbital] should not be in pet food and its presence as detected by the FDA in these products renders them adulterated.”

This case exists at a complicated overlap of different consumer and food agencies. The FDA oversees pet food; the U.S. Department of Agriculture oversees meat and slaughterhouses; and the Federal Trade Commission handles complaints of false advertising. Customers who paid premium prices for “human-grade” beef pet food that was neither have a valid FTC complaint.

The evidence of horse DNA is important because it may help explain where meat containing harmful levels of pentobarbital originally came from. Cattle generally aren’t killed using the drug, but horses often are. After death using the drug, horses can be sent for certain kinds of rendering, but their meat can’t be eaten.

The beef in the recalled products may not be what it appeared, either. In a statement last week warning pet owners not to feed their animals these products, the FDA shared that documents showed the pet food plant had received a shipment labeled: “Inedible Hand Deboned Beef – For Pet Food Use Only. Not Fit For Human Consumption.”

At the time this food was produced, Evanger’s advertised its food as using human-grade meats.

If further investigation shows that horse meat was used in the beef pet food, it would not be the first time that Evanger’s has told customers that the wrong animal was in a can. In 2011, the FDA sent the company a warning letter after tests showed that its lamb and duck dog and cat foods contained beef instead. That investigation was closed in 2013.

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