Feeding dogs raw (uncooked) meat increases their risk of excreting E. coli that cannot be killed by a widely used antibiotic—ciprofloxacin, UK researchers have found from a study of 600 healthy pet dogs.
E. coli, which can cause food poisoning, is also the UK’s most common cause of urinary tract and bloodstream infections, which can be life-threatening.
Ciprofloxacin belongs to a group of antibiotics called fluoroquinolones, which are used to treat a range of bacterial infections in humans and animals.
The World Health Organization classes these antibiotics among the highest-priority critically important antibiotics.
The study by a team at the University of Bristol and published in One Health, looked for ciprofloxacin-resistant E. coli carried in the intestines of 600 healthy pet dogs.
The research team asked the dog owners to complete a survey that provided details about their dog, the dog’s diet, environments the dog walked in and if the dog had been treated with antibiotics.
The microbiology data along with the survey data enabled statistical analysis, which showed that feeding uncooked meat to dogs was the only significant risk factor associated with excretion of these resistant bacteria in the dog’s faeces.
This work supports other published studies demonstrating associations between dogs being fed raw meat and excreting resistant E. coli.
In the UK, reduced ciprofloxacin use by GPs has led to a decrease in ciprofloxacin resistance in E. coli from human infections.
There has also been an almost total cessation of the use of fluoroquinolones to treat farmed animals in the UK. However, fluoroquinolone use, and resistance remains at very high levels around the world.
“Our aim was not to focus on raw dog food, but to investigate what might make a dog more likely to excrete resistant E. coli in its faeces,” Dr Jordan Sealey said.
“Our study found a very strong association between excreting ciprofloxacin-resistant E. coli and feeding dogs a raw food diet.”
When dogs excrete resistant bacteria into the environment and home, there is the potential for these bacteria to be passed on to their owners and other people. Once a person swallows some E. coli, these bacteria can sit in their intestines for years before causing an infection.
When E. coli is resistant to important antibiotics like ciprofloxacin, infections are more difficult to treat, meaning patients are more likely to be hospitalised and die.