People can get pretty fired up when I talk about raw diets for pets. I’ll start off with my personal bias: I’d rather not see pets fed raw meat and raw animal-based products (e.g. pig ears and various bits-o-cow you can find in pet stores). There are clear risks to pets and owners from raw diets, including infectious and non-infectious issues. I’ll stay in my lane and focus on the infectious disease topics here.

We, and others, have shown that pets fed raw diets have high rates of shedding of certain bacteria that can cause disease.  I’ve been involved in various investigations of disease in dogs and cats (and some in owners) linked to raw diets for pets. At the same time, I’m a realist and recognize that the risk isn’t overwhelming for most people and pets, and not everyone is going to change their pet’s diet as a result of said risk.

So, I approach raw diets from the standpoint of “I’d rather not see them used, and there are almost always acceptable, lower risk commercial cooked diets available” but at the same time “The risk is probably low for most dogs and owners, but some situations are clearly higher risk.” I’d rather spend my energy focusing on situations where I think it’s a really bad idea, and try to give some guidance to people that insist on doing it. That way I can still engage people, rather than push them away with a more dogmatic approach.  That’s why we created a factsheet for pet owners about raw diets (to be honest it needs an update, but it’s still useful as many of the risks themselves haven’t changed… but more on that below).

We have to keep our eye on this issue and be alert for new information that changes the story in any direction.  Initial work on raw diets focused on Salmonella, and that’s still an issue.  However, in the past few years, my bigger concern has been antibiotic-resistant bacteria like E. coli. Dogs fed raw diets have much higher rates of shedding of multidrug-resistant Gram negative bacteria like E. coli in feces. Eating a raw diet seems to be as much of a risk factor as the dog being treated with antibiotics (probably because antibiotic treatments are short term while feeding is much longer term exposure). What this means for human or animal health isn’t clear, but raw pet food-associated infections have been identified in people and a dog carrying a resistant bacterium in its gut is likely at increased risk of developing an infection with that bacterium. For E. coli and related bugs, urinary tract infections would be among the most common issues, but a wide range of disease can potentially occur.

That’s a long introduction to the paper that prompted this post. The study in question (Mounsey et al, One Health 2022) doesn’t change the story at all, but adds more pieces of evidence.

In this study, they collected history and fecal samples from puppies at 16 weeks of age. Those samples were tested for antimicrobial-resistant E coli.

  • They ended up recruiting 223 puppies, 43 of which were being fed a raw diet.
  • 32 (74%!) of the raw-fed puppies were shedding E. coli resistant to at least one antibiotic, compared to 76/180 (42%) of the other puppies.
  • They looked at a number of other potentially contributing factors, such as where the dogs were walked, and didn’t find anything else that was associated with resistant E. coli shedding.
  • When they looked at resistance to individual antibiotics, raw diet feeding was associated with resistance to many drugs, with the strongest effect for fluoroquinolones, a drug class classified in the highest priority critically important antimicrobial group for humans.
  • When they looked more at the fluoroquinolone-resistant isolates, they found that many were strains that were found in urinary tract infections in people in the same area.

So, I’ll stick with my “I’d rather not have people feed their pets raw diets” line, with the added “I  REALLY don’t want to see those diets fed to very young pets, old pets or pets with immunodeficiencies, OR in households where someone is very young, elderly, pregnant or immunocompromised.”

If someone’s intent on feeding a raw diet, risk reduction is the key (risk elimination being impossible).

Diet selection is part of that. Some diets are treated to reduce (not eliminate) microbial contaminants, usually using high pressure pasteurization, which applies pressure to kill bacteria and parasites in the product. It’s not perfect by any means, but it’s useful in decreasing the microbial load. Sticking with companies that provide information about their quality control and risk reduction plan is good too. Some raw diet companies do a good job. Others… well, not so much.

Beyond that, it’s a lot of good ol’ common sense, hygiene and hand washing. Our raw diet factsheet has some information, and any good food safety infosheet will have a lot of tips that apply equally to handling raw diets for pets as they do to handling raw products during food preparation for people.