A study developed by researchers from the Applied Biomolecular Sciences Unit (UCIBIO) revealed that raw food sold for dogs is “a major source of antibiotic-resistant bacteria with a potential risk to public health”.
In a statement, UCIBIO reveals on 12 July that the study was aimed at understanding whether pet food was "a potential source of spread of antibiotic-resistant bacteria."
In this regard, the researchers analyzed the presence of 'Enterococcus' [bacteria that can cause human infections, often difficult to treat] in samples of dog food sold in supermarkets and pet stores.
Cited in the statement, Ana Freitas, a researcher at UCIBIO and the Faculty of Pharmacy of the University of Porto (FFUP), says that “55 samples of dog food were included in the study (22 wet, eight dry, four semi-moist, seven treats and 14 frozen raw) of 25 brands available nationally and internationally”.
The study concluded that 54 percent of the samples under study contained 'Enterococcus' and of these 31 percent were multi-resistant, that is, "resistant to more than three antibiotics from different families, including antibiotics considered of last resort in the treatment of infections caused by different bacteria".
In addition, all frozen raw feed samples contained multi-resistant Enterococcus, including linezolid, a “last line” antibiotic used in the treatment of severe infections and considered “critically important” by the World Health Organization (WHO).
"Only three of the 41 samples of non-raw feed contained multi-resistant 'Enterococcus'," the statement said.
Genomic sequencing of some 'Enterococcus' from the raw samples for dogs, published in the journal Emerging Infectious Diseases, revealed that “these were similar to those from hospitalized patients in the UK, Germany and the Netherlands”.
“Some of the multi-resistant bacteria found proved to be identical to those found in hospitalized patients in different European countries”, he concludes.
The results of the analysis of bacterial susceptibility to antibiotics were published in the International Journal of Food Microbiology.
The researchers believe, based on the results obtained, that the trend to feed dog’s raw food may be contributing to "the international spread of clinically relevant bacteria".
Also quoted in the statement, Luísa Peixe, head of the UCIBIO laboratory and a professor at FFUP, says that European authorities “should raise awareness about the risks of providing raw diets to pets” as well as “review practices on selection ingredients and hygiene in the manufacture of these products”.
The researchers therefore make a recommendation for dog owners to wash “their hands with soap and water immediately after contact with animal food or animal waste”.