Raw Feeding: What the Pathogen Studies Found

In a UK study of 190 dogs, Salmonella was found in the faeces of 8 of 114 raw-fed dogs and none of the 76 dogs on cooked food (Groat et al., Journal of Small Animal Practice 2022). Raw-fed dogs were also far more likely to carry gut bacteria resistant to antibiotics.

While many raw-feeding owners in the study said their dog’s stools and breath improved, those were owner impressions. The bacteria were measured in a lab.

→ What Goes in the Bowl: Commercial Food and Supplements, Without the Marketing

---

1. The UK dog study

The dogs. 190 dogs from 140 UK households, recruited through social media in 2015. A dog counted as raw-fed if any part of its regular diet, at least once a week, was uncooked.

The test. Owners sent one faecal sample per dog. The lab looked for Salmonella and for E. coli resistant to antibiotics.

Funding. A veterinary charity’s student grant and the authors’ university funded the work. The authors declare no conflicts of interest.

---

2. What it found

Finding	Raw-fed (114 dogs)	Cooked diet (76 dogs)
Salmonella	7%	0%
E. coli resistant to at least one antibiotic	54%	17%
E. coli resistant to three or more antibiotic classes	25%	4%
E. coli resistant to a class of antibiotics important in human medicine	31%	4%

After adjusting. Raw feeding stayed a strong risk factor after the authors accounted for other factors and for dogs sharing a home.

Why owners chose raw. The most common reasons were adverts (28%) and friends (26%).

Our note: The paper studied healthy dogs and didn’t follow them up, so it can’t say whether carrying these bacteria harms the dog.

---

3. What a US food-testing study found

The test. US government labs tested about 1,056 pet food samples over two years (Nemser et al., Foodborne Pathogens and Disease 2014) ⚠️ abstract read.

Dry food. Only 2 of 480 dry and semi-moist samples tested positive.

Raw food and jerky treats. Of 576 samples of raw food, jerky-type treats and exotic animal feed, 66 had Listeria and 15 had Salmonella. The positives came from the raw foods and jerky treats.

Our note: We read only the abstract, which doesn’t split results between raw food and jerky treats.

---

4. What the studies can’t tell you

Who took part. The authors say volunteers may not represent all UK dogs. There’s no standard raw diet, so risk may vary.

Owner answers. Questions about recent antibiotics relied on owners’ memory.

Whether dogs got sick. Neither study followed dogs to see whether they became ill.

Small slips. The UK paper’s abstract says Salmonella was found in “eight (4%) raw fed dogs”. Eight is 7% of the raw-fed dogs, and 4% of all dogs tested. One odds ratio’s confidence interval also shares its upper limit with the row below, which may be a copying error.

Our note: Both studies point to risks for people handling raw food. We leave human health out, so check public health advice on safe handling.

Our note: The UK data are from 2015 and the US data are older. We didn’t find newer UK testing.

---

5. What we could not verify

Commonly said	What we found
“Raw food is natural, so it’s clean”	No. Salmonella appeared only in raw-fed dogs.
“Raw feeding improves stools and breath”	Owner reports only. The study didn’t measure these.
“Dry food is sterile”	Not quite. 2 of 480 dry and semi-moist samples tested positive.

---

Sources

• Groat EF, Williams NJ, Pinchbeck G, Warner B, Simpson A, Schmidt VM. UK dogs eating raw meat diets have higher risk of Salmonella and antimicrobial-resistant Escherichia coli faecal carriage. J Small Anim Pract 2022: 190 dogs, 140 UK households, 2015. Funded by a veterinary charity’s student grant and the University of Liverpool
• Nemser SM, Doran T, Grabenstein M, et al. Investigation of Listeria, Salmonella, and toxigenic Escherichia coli in various pet foods. Foodborne Pathog Dis 2014: US government labs, about 1,056 samples. ⚠️ abstract read

Always confirm with your vet before acting on anything on this page.