Barking up the Right Tree

After years of randomly testing livestock feeds and pet foods sold in stores to ensure their contents matched nutrition labels, the Michigan Department of Agriculture and Rural Development (MDARD) landed a grant to look for something else: pathogens.

“People are in direct contact with their pets and pet food, so we knew it was an important animal and human food safety project,” says April Hunt, feed and fertilizer specialist for the department.

Within a few months in 2012, the team found a needle in a haystack –salmonella in a six-pound bag of pet food. To find out more about the pathogen and prevent its spread, the program reached out to MDARD’s Geagley Laboratory Microbiology Section Manager Ted Gatesy. Salmonella causes gastrointestinal illness and can be transmitted through contaminated food or unwashed hands. Pet owners can contaminate their own food through unwashed hands after handling contaminated pet food.

The lab staff recovered salmonella from the bag of pet food. They sent the isolate to the Michigan Department of Community Health’s laboratory, where it was further identified by its DNA fingerprint. This allowed the team to search for it in a national database of foodborne illnesses with unknown causes maintained by the U.S. Centers for Disease Control and Prevention.

“Our little six-pound bag of pet food with salmonella was linked to human illnesses in 20 states and two Canadian provinces,” Hunt says, adding that 53 human illnesses were linked to the discovery.

The April 2012 pet food recall was expanded eight times that year, eventually encompassing over 60 million pounds of pet food.

In an effort to continue improving the safety of pet food – and the humans that interact with it – after the grant expires, the state legislature is considering an updated feed law that would use fees to fund inspections.