by Chelsea Kent
Conversations around raw pet diets often circle back to the risk of Salmonella or E. coli. Critics argue that raw food inevitably leads to pathogen shedding, while supporters point to the benefits of minimally processed diets. But what does the data actually say when we look across multiple published studies?
The Data at a Glance
Five major studies from North America, Europe, and Africa collectively tested 3,435 dogs. Here’s what they found:
- Overall prevalence: Only 60 dogs (1.7%) were found shedding any serovar of Salmonella or E. coli in their stool, regardless of diet.
- Raw-fed prevalence: Just 10 dogs (0.29%) were raw-fed and also tested positive. That’s 16.6% of all positives.
- Confirmed diet↔feces matches: Across all five studies, only 5 dogs (0.15% of the total sample, 8.3% of all positives) were confirmed to shed the exact same serovar found in their food.
- Non-raw-fed positives: The vast majority of shedding (50 dogs, 1.5% overall) was in non-raw-fed dogs. However, because those diets weren’t serotyped, it’s impossible to know whether the pathogen came from food or other sources, just as diet cannot be a confirmed source in raw fed dogs who shed pathogens in their feces but serotyping was not done.
|
Category |
Value |
% of All Dogs (n=3,435) |
Notes |
|
Total dogs tested across 5 studies |
3,435 |
100% |
Ontario, USA multilab, Spain, Ethiopia, UK |
|
Dogs fed raw (explicit or estimated) |
179 (explicit) / 193–220 (incl. est.) |
5.2% (explicit) / 5.6–6.4% (incl. est.) |
Only one study gave a reliable count (179). Others partial/est. |
|
Dogs shedding pathogens (any diet, any serovar) |
60 |
1.7% |
Includes Salmonella and E. coli |
|
Raw-fed dogs shedding pathogens |
10 |
0.29% (16.6% of positives) |
Most studies noted raw as a risk, but absolute numbers are small |
|
Confirmed raw-fed dogs with diet↔feces serovar match |
5 |
0.15% (8.3% of positives) |
Only from Finley et al., 2007; no CFU load reported |
|
Non-raw-fed dogs with confirmed diet↔feces match |
0 |
0% |
Because diet serovars not tested, cannot be determined |
|
Non-raw-fed dogs shedding pathogens (unconfirmed link) |
50 |
1.5% (83.3% of positives) |
Majority of shedding cases were in non-raw-fed dogs |
What This Means
- Pathogen shedding is uncommon. Less than 2% of dogs in these large cohorts were shedding Salmonella or E. coli at all, regardless of dietary composition or contamination.
- Raw-fed shedding is even rarer. Only 0.29% of all dogs tested were raw-fed and positive — a number that looks very different from the alarmist rhetoric often repeated.
- Direct causal proof is vanishingly rare. Out of more than 3,400 dogs, just five had a confirmed match between a pathogen in their food and in their stool. All five came from a single small Canadian experiment (Finley et al., 2007), which did not measure pathogen load.
- Non-raw-fed dogs shed too. 83% of positive shedders were eating conventional diets, but without diet serotyping we can’t link their shedding to food. Other exposures — environment, treats, water, or existing carriage — may explain these cases.
Regulatory Context: Recalls Tell Another Story
According to FDA recall data (analyzed by Truth About Pet Food), when we look at recalls by poundage over the last five years, the vast majority are tied to kibble and conventional diets, not raw. This matters, because poundage reflects scale of exposure. A handful of raw recalls attract outsized media attention, but the data show conventional products pose a more widespread risk when measured by sheer volume.
The numbers are clear:
- Out of thousands of dogs tested worldwide, pathogen shedding is rare.
- Confirmed dog-level diet↔feces matches are exceedingly rare — just 5 dogs in the published, searchable record.
- Most shedding occurs in dogs not fed raw, though source attribution is missing.
Rather than blanket condemnation, the evidence calls for nuance:
- Contamination events — whether in raw or kibble — matter, not “rawness” itself.
- Proper sourcing, processing, and handling can minimize risk in any diet type.
- Regulators should weigh actual prevalence and exposure volume before issuing sweeping claims.
Note that all pet foods, whether cooked, freeze dried, dehydrated, or raw, have risks. Statistics indicate that pathogen recalls are most commonly associated with kibble products.
References:
– U.S. multilab survey (2012–2014) — 2,965 fecal samples from dogs & cats submitted to 11 diagnostic labs; dogs: 2.5% positive (60/2,422). J Clin Microbiol.
– Ontario household dogs (2005–2006) — 138 pet dogs sampled repeatedly; 23.2% of dogs had at least one positive fecal sample over the study period. (Serial sampling inflates % “ever positive”.)
– Ethiopia (household dogs) — 415 rectal swabs; 6.3% positive overall (15.2% in diarrheic, 5.5% in apparently healthy). BMC Vet Res.
– Spain (apparently healthy dogs) — 325 rectal swabs; 1.8% positive. BMC Vet Res.
– Other regional studies commonly report ~1–10% in healthy pets (method, population, and feeding practice matter).