Raw pet food, cattle linked to drug-resistant salmonella outbreak affecting mainly kids

An outbreak of extensively drug-resistant salmonella has been linked to raw pet food and contact with cattle, according to the Public Health Agency of Canada.

In a Nov. 11 public health notice, the agency said 40 cases have been confirmed in six provinces, including 21 cases in Quebec, 14 in Ontario, two in Nova Scotia, and one each in Manitoba, New Brunswick and Prince Edward Island. Thirteen people have been hospitalized.

Although cases date from July 2020 to September 2023, the outbreak is considered ongoing as illnesses continue to be reported. While there have been no human deaths, some infected dogs and cattle have died. Children under five represent 43 per cent of all cases.

Jennifer Ronholm, an associate professor of animal science, food science and agricultural chemistry at McGill University, says extensively drug-resistant salmonella was first detected in Canada in cattle in 2019.

“In terms of antibiotic-resistance in salmonella, it’s unfortunately getting more common every year,” Ronholm told CTV News. “In 2010, about 10 per cent of the salmonella we were seeing in Canada was multi-drug resistant, and by 2019 we’re seeing over 60 per cent being multi-drug resistant.”

Ronholm believes the outbreak is likely affecting many more animals than health officials currently know about.

“This is a little bit rare that something goes on this long, but it’s not unheard of,” Ronholm explained. “What it indicates is we haven’t found the source yet, so you probably have a source at a processing facility, or a source at a distributor, or a source on a farm somewhere where people are sourcing their ingredients that has an ongoing outbreak but doesn’t know it yet. So until we can find the exact source of the contamination, there’s not much we can do about it.”