Multi-drug Resistant Bacteria Found in Dog Food

Understandably, the world has been hyperfocused on the global SARS CoV-2 pandemic. It has wreaked – and continues to wreak – havoc on many parts of our world. At the same time, there are other threats to the global health order to which we must pay attention, and one of these threats come from what we feed Fido.

Researchers tested fifty-five samples of industrial dog food (25 brands; 22 wet, 14 raw frozen, 8 dry, 7 treats and 4 semi-wet) for various bacteria. The results were alarming:

Enterococcus (n = 184; 7 species; >85% E. faecium and E. faecalis) were detected in 30 samples (54%) of different types (14 raw, 16 heat treated-7 dry, 6 wet, 3 treats). E. faecium and E. faecalis were more frequent in dry and wet samples, respectively. More than 40% of enterococci recovered were resistant to erythromycin, tetracycline, quinupristin-dalfopristin, streptomycin, gentamicin, chloramphenicol, ampicillin or ciprofloxacin, and to a lesser extent to linezolid (23%; optrA, poxtA) or vancomycin and teicoplanin (2% each; vanA). Multidrug-resistant isolates (31%), including to vancomycin and linezolid, were obtained mostly from raw foods, although also detected in wet samples or treats, and mainly from culture media supplemented with antibiotics. 

Now, of course, these multidrug resistant bacteria are not as contagious as SARS CoV-2 and its multiple variants. They are not as contagious as the measles virus or even influenza. It is highly improbable that there will be a global pandemic from a vancomycin-resistant enterococcus.

At the same time, these multidrug resistant bacteria can cause serious infections, and if someone gets infected by any of them, there are few – if any – antibiotics that can treat these infections. Linezolid and vancomycin are “last resort” medications that we use to treat highly resistant bacteria. If there is an enterococcus that is resistant to these drugs, as an ICU physician, this prospect is frightening.

The findings of this research should further emphasize the importance of not using antibiotics in farm animals unless it is absolutely necessary. As important is what we do when we handle pet food – especially raw pet food – and pet fecal matter. Given this research, it is crucial that we practice good hand hygiene and thoroughly wash our hands with soap and water.

Yes, viral pandemics that kill millions of people around the world are horrific and must be dealt with. At the same time, we cannot lose focus on other threats to global public health, and one of these threats is multidrug resistant bacteria. We need to remain vigilant against these threats as well.