80% of Commercial Raw Diets Tested Positive for Antibiotic-Resistant E. Coli
van Bree et al. (2018) tested 35 commercially available raw meat-based diets and found antibiotic-resistant E. coli in 80% of them, Listeria in 43%, and Salmonella in 20%. Those numbers are not from fringe products — they represent the commercial raw diet market in a developed country with food safety regulations.
At the same time, some dogs appear to thrive on well-formulated raw diets, and owners report improvements in coat quality, stool consistency, and energy levels. The evidence supports legitimate concerns about pathogen risk and nutritional adequacy while also acknowledging that not every raw-fed dog gets sick. What the evidence does not support is the degree of certainty with which either side — advocates or critics — makes its claims.
Pathogen Contamination: The Core Safety Concern
van Bree et al. (2018) tested 35 commercially available raw meat-based diets (frozen products, not home-prepared) and found:
- 23% contained E. coli O157:H7 or other Shiga toxin-producing E. coli (STEC).
- 80% contained antibiotic-resistant E. coli.
- 43% contained Listeria monocytogenes.
- 20% contained Salmonella species.
- 23% contained Sarcocystis (a parasitic organism).
Freeman et al. (2013) reviewed multiple studies confirming that raw meat products intended for pet consumption are frequently contaminated with pathogenic bacteria at rates significantly higher than human food-grade meat — in part because pet food production is subject to less stringent processing requirements.
The contamination risk has two dimensions:
Risk to the dog. Healthy adult dogs have greater resistance to Salmonella and many enteric pathogens than humans, and clinical salmonellosis from raw food is uncommon in immunocompetent adult dogs. However, puppies, senior dogs, and dogs with inflammatory bowel disease, immune-mediated conditions, or concurrent illness have reduced gut barrier function and greater susceptibility.
Risk to humans. Dogs fed raw diets shed Salmonella and other pathogens in their feces and saliva. This creates a zoonotic risk for household members, particularly children, elderly individuals, and immunocompromised people. The AVMA’s policy against raw feeding is primarily driven by this public health concern.
Nutritional Adequacy
Schlesinger and Joffe (2011) reviewed published analyses of home-prepared raw diets and found that the majority tested were nutritionally unbalanced:
- Calcium:phosphorus ratios were frequently abnormal (either deficient or excessive calcium depending on bone content).
- Vitamin D, zinc, iodine, and vitamin E deficiencies were common.
- Protein and fat content varied widely and was often excessive.
- Home-prepared raw diets formulated without professional guidance were the most consistently imbalanced.
Commercially formulated raw diets (frozen or freeze-dried products designed to meet AAFCO nutrient profiles) had better nutritional profiles than home-prepared diets, but quality varied significantly between brands. Not all commercial raw products are formulated by veterinary nutritionists, and AAFCO compliance is based on either calculated nutrient profiles or feeding trials — the latter being substantially more meaningful.
Claimed Benefits: What Evidence Exists
Proponents of raw diets claim improvements in coat quality, dental health, stool quality, energy levels, and reduced allergy symptoms. The evidence for these claims:
Microbiome composition. Sandri et al. (2017) found that dogs fed raw meat-based diets had different fecal microbiome profiles compared to kibble-fed dogs, with higher microbial diversity in some measures. Whether this translates to health benefits is unclear — different is not necessarily better. See microbiome and canine longevity for broader context.
Dental health. Raw meaty bones may provide mechanical cleaning of teeth. However, bone consumption also carries risk of tooth fractures, esophageal obstruction, and gastrointestinal perforation. The dental benefit must be weighed against these risks. See dental disease.
Coat and skin quality. Some owners report improvements. Higher fat content in raw diets (compared to many kibbles) may explain this. The same effect can often be achieved with omega-3 supplementation added to any diet.
Stool quality. Raw-fed dogs typically produce smaller, firmer stools. This reflects higher digestibility of raw animal protein and lower fiber content rather than inherently superior gut health.
Allergy improvement. Dogs with food allergies to specific proteins may improve on raw diets simply because the protein source changes. The improvement is not unique to raw feeding — cooked novel-protein diets produce the same benefit. See elimination diet protocol.
The AVMA and Veterinary Professional Positions
The AVMA adopted a policy in 2012 discouraging the feeding of raw or undercooked animal-source protein to dogs and cats, citing the risk of illness to pets and humans from pathogens present in raw protein. The American Animal Hospital Association (AAHA), Canadian Veterinary Medical Association (CVMA), and most European veterinary organizations hold similar positions.
These positions are based on the pathogen contamination data and the zoonotic risk to household members. They do not claim that raw diets cannot provide adequate nutrition — they argue that the infection risk is unnecessary given that cooked diets can provide equivalent or superior nutrition without pathogen exposure.
If You Choose to Feed Raw
Despite professional organization recommendations, many owners choose raw feeding. If a raw diet is used, the following risk-reduction strategies are evidence-supported:
- Use commercially formulated products that meet AAFCO nutrient profiles, preferably those that have passed feeding trials. Avoid home-prepared diets unless formulated by a board-certified veterinary nutritionist.
- Handle raw food with the same hygiene practices used for raw meat in human food preparation. Wash hands, bowls, and surfaces after every feeding. Disinfect food preparation areas.
- Store raw food at proper temperatures. Freeze until use; thaw in the refrigerator, not at room temperature.
- Do not feed raw diets to immunocompromised dogs, puppies, or seniors with significant organ disease.
- Monitor stool quality and body condition. Regular veterinary check-ups with bloodwork can identify nutritional deficiencies before they produce clinical signs.
- Consider high-pressure pasteurized (HPP) products. Some commercial raw diets use HPP to reduce pathogen load while preserving the raw format. This addresses some but not all contamination concerns.
- Inform your veterinarian. Accurate dietary history is important for clinical decision-making.
The Middle Ground: Gently Cooked Diets
For owners seeking the perceived benefits of fresh, whole-food diets without the pathogen risk of raw feeding, gently cooked diets represent a middle ground. Cooking to internal temperatures sufficient to kill Salmonella (74 degrees Celsius) eliminates the primary food safety concern while preserving nutrient profiles closer to raw than to heavily processed kibble.
Several commercial fresh food companies (The Farmer’s Dog, JustFoodForDogs, Nom Nom) offer cooked whole-food diets formulated to AAFCO standards. See diet review guides for coverage of specific options.
Limitations
The raw diet evidence base is limited by small study sizes, high owner selection bias (raw feeders tend to be more engaged with their dogs’ health overall, confounding outcomes), and difficulty controlling for diet composition across studies. Long-term controlled feeding trials comparing raw vs. cooked diets of identical nutrient composition in dogs do not exist. The pathogen risk data, while robust, describes contamination rates — not clinical illness rates — and the gap between exposure and disease is not well characterized in healthy adult dogs.
Frequently Asked Questions
Are raw diets nutritionally complete for dogs?
Studies of homemade raw diets consistently find nutritional imbalances — multiple analyses show that 60-95% of homemade raw recipes are deficient in one or more essential nutrients (commonly calcium, zinc, vitamin D, and iodine). Commercial raw diets formulated to AAFCO standards are more likely to be complete, though quality varies between manufacturers.
Do dogs on raw diets have shinier coats and better health?
Owners frequently report improved coat quality, smaller stools, and higher energy on raw diets. However, these observations come from unblinded owner assessment, making placebo effect and confirmation bias likely contributors. The few controlled studies comparing raw to high-quality cooked diets show minimal differences in objective health metrics.
What do veterinary organizations say about raw diets for dogs?
The AVMA, AAHA, WSAVA, and FDA all recommend against feeding raw meat-based diets to dogs due to documented pathogen contamination risks to both animals and humans. These positions are based on microbiological evidence rather than nutritional adequacy concerns. No major veterinary organization endorses raw feeding.
Is gently cooked food a safer alternative to raw?
Yes. Gently cooked diets (home-prepared or commercial) eliminate the majority of pathogenic bacterial contamination while preserving more nutrients than heavily processed kibble. When properly formulated with a veterinary nutritionist’s guidance, gently cooked diets address the food safety concerns of raw feeding while potentially providing the whole-food ingredient benefits that raw diet proponents value.
Bottom Line
Raw meat-based diets carry documented pathogen contamination risk that is higher than cooked diets, creating both animal and human health concerns. Nutritional adequacy varies significantly — home-prepared raw diets are frequently imbalanced, while well-formulated commercial raw products can meet nutrient requirements. Claimed health benefits (coat quality, dental health, stool quality) are plausible but not uniquely attributable to raw feeding. Owners choosing raw diets should use commercially formulated products, practice strict food hygiene, and maintain regular veterinary monitoring. Gently cooked whole-food diets offer a compromise that eliminates pathogen risk while providing many of the perceived benefits of fresh feeding.