Detections of Salmonella in raw meat-based pet food in the United Kingdom have hit their highest ever level, according to a report. This poses a risk to people who handle it.

Data on Salmonella reports from livestock species and in feed and pet food in England, Wales and Scotland was collected by the Animal and Plant Health Agency (APHA) for 2021.

In 2021, 5,625 isolations of Salmonella from humans were reported to the UK Health Security Agency (UKHSA), Public Health Wales and Public Health Scotland. This is up from 5,362 in 2020 but down from 9,572 cases in 2019. Salmonella Typhimurium caused the most infections, followed by Salmonella Enteritidis and Salmonella Infantis. A marked impact on national surveillance for gastrointestinal pathogens was seen in 2020 and 2021, coinciding with the COVID-19 pandemic.

This past year, the number of Salmonella isolation reports from cattle, sheep, pigs and poultry dropped by 14 percent to 2,809 versus 3,279 in 2020. Compared to 2020, there was an increase in isolations from cattle, sheep and pigs but this was offset by decreases from chickens, turkeys and ducks.

Reports of Salmonella Montevideo were much higher than in 2020, Salmonella Dublin increased and Salmonella Infantis rose to 42 isolations from one in 2020. Salmonella Typhimurium was also higher than in 2020. Findings of Salmonella Enteritidis, Salmonella 13,23:i:- and Salmonella Indiana fell.

Feed and pet food
There were 835 isolations of Salmonella from animal feedstuffs in 2021, mostly from feed ingredients or products associated with testing under Animal By-Products regulations. This is an increase compared with 757 isolations in 2020. There were 124 isolations of regulated Salmonella serovars from animal feed and related products.

There were 295 isolations of Salmonella from pet food intended to be fed raw and 71 cases of regulated serovars were found. Salmonella Typhimurium and Salmonella Infantis were amongst the top four types isolated. Raw meat pet food is known to harbor pathogens including Salmonella. Positives from these products have increased in recent years, with 295 being the most so far.

“Contaminated raw meat pet food, which does not undergo any heat treatment to deactivate pathogens, may therefore represent a potential source of infection to both the dogs consuming it and people who handle it, especially if insufficient hygiene measures are adopted,” said the report.

Several multidrug resistant strains, some resistant to critically important antimicrobials, were detected in dogs, cats and raw pet food. This partly reflects Salmonella from dogs being made reportable in Great Britain in early 2021, so more isolates were tested compared to previous years. However, findings show the potential for transmission from pets to people.

Results in other animals
Isolations of Salmonella from cattle went up to 521. Salmonella Dublin was the most common type followed by Salmonella Mbandaka and Salmonella Typhimurium.

Isolations of Salmonella from sheep almost doubled to 144 and also went up for pigs to 223. Salmonella Typhimurium and its monophasic variants were responsible for almost three-quarters of cases in pigs in 2021.

Including National Control Program and non-statutory surveillance data, there were 1,671 isolations of Salmonella from chickens, which is down from 2,221 in 2020. The main types were Salmonella Montevideo and Salmonella Mbandaka.

There were 140 isolations of Salmonella from turkeys compared to 196 in 2020. Salmonella Anatum was the most common followed by Salmonella Derby. Cases of Salmonella in ducks almost halved to 110 in 2021.