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Four brands of dog food under the JM Smucker Co. umbrella have been recalled after a Washington, D.C. TV station tested one of the brands and found traces of a euthanizing drug used on dogs, cats, and horses in 60% of the samples.

The AP reports that shipments of cans of Gravy Train, Kibble ‘N Bits, Skippy, and Ol’ Roy wet food have been pulled back after pentobarbital was found in nine of the 15 cans of Gravy Train that WJLA tested. The station, which commissioned a lab specializing in food testing for contaminants, also tested around two dozen other brands over several months, but there were no significant findings.

People notes that Gravy Train is produced by the Smucker Co.’s Big Heart Pet Brands, which also makes Meow Mix, 9Lives, and Pounce pet edibles. The investigation was spurred after the death of a Washington state woman’s dog a year ago.

All four of Nikki Mael’s dogs got sick on New Year’s Eve 2016 after eating canned Evanger’s dog food, and one, Talula, didn’t make it. Mael sent the food out for testing, and the lab found it contained pentobarbital, which is banned from use in pet or human food.

Efforts are now focused on how the pentobarbital got into the Gravy Train samples, with the FDA jumping into the investigation; the AP notes a supplier that provides one of the brand’s lesser ingredients is being looked at.

One somewhat stomach-churning possibility being bandied about: animals that were put down somehow ended up in the pet food.

A rep from JM Smucker tells WebMD “extremely low levels” of pentobarbital aren’t risky for animals, but that “the presence of this substance at any level is not acceptable to us and not up to our quality standards.” (The FDA also warned about bones for dogs.)

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