Dog food sold by some international brands can spread antibiotic-resistant superbugs all over the world.
When researchers in Europe conducted tests on wet, raw and cooked dog food from 25 different brands, they detected Enterococci bacteria in just over half of the samples.
As the team waited to find some opportunistic germs driving these meals, the rate and variety of bacteria found was “suddenly high,” the scientists explained in a research paper to the CDC.
Enterococcal bacteria can cause surgical wound infection and urinary tract infections in humans, and in recent years, they have become resistant to many and sometimes all antibiotics in our arsenal.
Dog food, especially the raw type, can put pet owners at risk of contracting those superbugs.
While some of the microbes found in dog food samples responded to medication, more than 40 percent showed resistance to a wide range of antibiotics, including erythromycin and ampicillin. Of that number, 23 percent were resistant to recent treatments, such as linezolid, as well.
The study was conducted only using dog food purchased in Portugal, but the fact that most of these brands ship worldwide is not a good sign. If this type of bacteria infects a person, it can be extremely difficult to treat.
While raw, meat-based diets are growing in popularity among many dog owners, the potential risks to human health are rarely addressed.
“Close human contact with dogs and the commercialization of brands studied in different countries pose an international public health risk,” says molecular geneticist Ana Freitas of the University of Porto.
“European authorities need to review awareness of potential health risks when feeding pets raw foods and producing dog food, including ingredient selection and hygiene practices.”
Poo dogs and dog food have long been known to carry a reservoir of resistant bacteria that can endanger the health of their owners. Still, the researchers explain that this is the first study to describe the resistance of enterococci to last-line antibiotics in dog food.
In the end, the authors found every single sample of raw dog food they tested Enterococcus. Only a few wet and dry foods contained similar microbes.
The fact that superfoods are more common in raw meat is not a big surprise – after all, heat is a pretty great way to kill pathogens – but the incidence rate found in this study is much higher than what has been discovered in the past
A two-year study in the United States, for example, also found that raw animal feed was more likely to be contaminated with disease-causing bacteria, but only about a quarter of the time.
While many public health experts, such as the Centers for Disease Control and Prevention, warn against feeding pets with raw diets, for fear of Salmonella AND Listeria, there are currently no such warnings about cooked dog food.
This may be an oversight, as current research has actually revealed some antibiotic-resistant bacteria in dry food, wet food and dog treatments.
As a result, researchers argue that the way raw meat source and handling by dog food companies should be reviewed “urgently”. Clearly, many pathogens are slipping through the cracks.
Further samples from more brands are needed to see how ubiquitous this issue is, especially among cooked foods. Risk assessments should also be performed to see how microbes in pet food can ultimately affect human health.
In the meantime, staying away from raw dog food and practicing safe hygiene at home is the best bet of a pet owner if they do not want to catch a bad bug.
“Dog owners should always wash their hands with soap and water immediately after treating pet food and after taking feces,” says Freitas.
The study was published in International Journal of Food Microbiology.