Pet Foods: Raw vs. Cooked Food Diets and Bacteria Concerns

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Pet Foods Raw vs. Cooked Food Diets and Bacteria Concerns


The debate over which type of diet is best for dogs and other pets – raw meat-based or cooked meat-based – often stirs strong emotions and polarizes people into taking “sides”, often with no room for acceptance of the other viewpoint.

Proponents of raw food diets cite numerous benefits, including:

  • More closely mirrors the evolutionary diet of wolves and wild dogs.
  • Dogs are carnivores designed to consume raw meat, bones and viscera.
  • Dog guardian controls the ingredient selection and sourcing (with home-prepared raw diets).
  • Higher in enzymes, vitamins and minerals than cooked foods.
  • Greater nutrient availability than cooked foods.
  • Improved skin and coat.
  • Reduced or eliminated ear infections.
  • Improved breath.
  • Fewer, less bulky, less foul-smelling stools.
  • Increased energy levels.
  • Reduced incidences of chronic disease.
  • Enhanced immune function and overall optimum health.

Opponents of raw food diets cite negatives, including:

  • May expose humans to higher levels of bacterial contamination.
  • Lack of studies showing that raw-fed dogs live healthier, longer lives.
  • Exposes vulnerable dogs to dangerous bacteria.
  • Home-prepared raw meat-based diets are often unbalanced, with deficiencies and/or excesses of certain nutrients.
  • Unbalanced raw diets are of particular concern with regard to growing puppies.
  • Bones, even raw, pose risk of obstruction and perforation.

Proponents of fresh, home-cooked diets cite numerous benefits, including:

  • Dog guardian controls the ingredient selection and sourcing.
  • Fresh, whole foods provide higher levels of nutrients than processed commercial foods.
  • Nutrients contained in fresh foods are more bioavailable than those contained in processed commercial foods.
  • Fresh meat, fruits and vegetables are more species-appropriate than commercial foods, especially kibble.
  • Improved skin and coat.
  • Reduced or eliminated ear infections.
  • Improved breath.
  • Fewer, less bulky, less foul-smelling stools than with commercial foods.
  • Increased energy levels.
  • Reduced incidences of chronic disease.
  • Enhanced immune function and overall optimum health. 

Opponents of fresh, home-cooked diets cite numerous negatives, including:

  • The main negative cited by opponents of home-cooked diets is that they are nutritionally unbalanced and can contribute to long-term vitamin/mineral deficiencies.
  • Opponents are commonly those invested in the mass-market commercial pet food industry.
  • Many mainstream veterinarians are also opposed to home-prepared diets.
  • We believe the vast majority mean well and are basing their beliefs on information provided by commercial pet food industry.

The main objection veterinarians typically raise regarding raw meat-based diets has more to do with human food safety issues than the validity of the diet for the animal. It goes without saying that proper food handling and safety techniques should be used when feeding a raw meat-based diet, just as they should when handling raw meat prior to cooking. In addition, vulnerable individuals, such as young children, the elderly, sick or immune-impaired people, young puppies or ill dogs should not be exposed to raw meat due to potential health risks. Common-sense precautions can greatly minimize the potential of bacterial contamination from raw food.

In our view, neither a raw nor cooked diet is inherently “better” than the other. We work with many dogs that thrive on raw food diets, and others that do not do well on raw foods but thrive on freshly prepared cooked foods. As we keep coming back to, every dog is an individual, and we believe that individual needs should outweigh a devotion to any one way of feeding.

Food Recalls

Many of us prefer to believe that the foods we and our pets eat are healthy and safe, even if we and they overeat fatty foods or those with a high glycemic index (high sugars and starches). However, both the human and pet food industries have more recently been inundated with food recalls for contamination with microbes including bacteria, viruses and parasites. Every food type has been implicated, even candies.

Salmonella, Listeria, Campylobacter, and E. coli

Food recalls in human and pet foods have primarily concerned contamination with Salmonella (many sources from animals, fish and plants), Listeria (mostly from bovine species), and Campylobacter bacteria, Hepatitis A virus in undercooked shellfish, and parasites.

The most recent pet food recall was for a cat food that was contaminated with both Salmonella and Listeria spp., and caused acute illness in 2 kittens and one died. It should be noted that the U.S. Food and Drug Administration (FDA) quoted a study from 2004 and stated, “Although L. monocytogenes can infect many animal species, dogs and cats rarely get listeriosis and they usually don’t show signs of disease. One reference mentions only six reported cases in dogs from 1947 to 2000, and the dogs showed a wide range of signs.”

Campylobacter spp. are now considered to be major triggering agents of acute polyradiculoneuritis (APN), an immune-mediated peripheral nerve disorder in dogs that shares many similarities with Guillain-Barre syndrome in humans. 

However, there is little information about the relationship between APN and Campylobacter spp. in dogs. Potential risk factors were investigated, particularly consumption of raw chicken in 27 client-owned dogs suffering from suspected APN and 47 healthy dogs, client or staff member owned. Where fecal samples were collected within 7 days from onset of clinical signs, APN cases were 9.4 times more likely to be positive for Campylobacter spp. compared to control dogs.

Further, a significant association was detected between dogs affected by APN and the consumption of raw chicken (96% of APN cases; 26% of control dogs). The most common Campylobacter spp. identified was Campylobacter upsaliensis. Thus, raw chicken consumption is clearly a risk factor in dogs for the development of APN, which potentially is mediated by infection with Campylobacter spp. Dr. Frieda Jorgensen, Public Health England, states 90% of Campylobacter cells are killed slowly by freezing, making it much less likely that the bacteria will be passed to humans. The temperature range for growth is 30- 45°C, with an optimum of 42°C. Survival at room temperature is poor, but
Campylobacter can survive for a short time at refrigeration temperatures – up to 15 times longer at 2°C than at 20°C.

Escherichia coli is a common fecal contaminant that can be found in many consumed human and animal foods.

W. Jean Dodds, DVM
Hemopet / NutriScan
11561 Salinaz Avenue
Garden Grove, CA 92843


Axelsson, E, Ratnakumar, A, Arendt, MJ, et al. “The genomic signature of dog domestication reveals adaptation to a starch-rich diet.” Nature. 2013; 495:360–364.

Baião DSS, da Silva DVT, del Aguila EM, et al. “Nutritional, bioactive and physicochemical characteristics of different beetroot formulations.” In: Food Additives, Chapter 2; Karunaratne DN, Pamunuwa G (Eds). 2017.  ISBN
978-953-51-3490-9, Print ISBN 978-953-51-3489-3, Published: September 6, 2017. doi: 10.5772/intechopen.69301.

Bailey J.S, Lyon B.G, Lyon CE, et al. “The microbiological profile of chilled and frozen chicken.” J Food Protection 2000; 63: 1228–1230.

“Blue Ridge Beef recalls pet food; kitten deaths reported.” Food Safety News. March 3,2018.

Carneiro MFMorais CSmall DM, et al. “Thimerosal induces apoptotic and fibrotic changes to kidney epithelial cells in vitro.” Environ Toxicol. 2015 Dec;30(12):1423-33. doi: 10.1002/tox.22012. Epub 2014 Jun 18.

Case LP, Daristotle L, Hayek MG, et al. Canine and Feline Nutrition (3rd Ed.) 2011, Mosby Elsevier, Maryland Heights, MS.

Dodds WJ. “Adjuvants and additives in human and animal vaccines.“ Med Res Archives 2016; 2(5):1-8.

Dodds WJ. “Diagnosis of canine food sensitivity and intolerance using saliva: report of outcomes.” J Am Hol Vet Med Assoc 2017.2018; 49:32-43.

Dodds, WJ, Laverdure, DR. Canine Nutrigenomics: The New Science of Feeding Your Dog for Optimum Health. 2015. DogWise Publishing, Wenatchee, WA, pp.323.

Dodds WJ, Laverdure-Dunetz, DR. The Complete Canine Nutrition Dog Health Program, Lessons 12 and 13, 2017-2018.

Dominguez SA, Schaffner DW. “Survival of Salmonella in processed chicken products during frozen storage.” J Food Protection 2009; 72: 2088–2092.

Duyff RL. “Cope with food allergies and other food sensitivities.” Academy of Nutrition and Dietetics Complete Food & Nutrition Guide. 5th ed. New York, N.Y.2017. Houghton Mifflin Harcourt.

“FDA says 44 deaths linked to kratom products; recall initiated.” Food Safety News. February 22, 2018.

Freeman LM, Michel KE. “Evaluation of raw food diets for dogs.” J Am Vet Med Assoc. 2001; 218: 705 – 709.

“Get the Facts about Listeria!” U S Food and Drug Administration, Center for Veterinary Medicine,

Harrison MA, Huang YW, Chao CH, et al. “Fate of Listeria monocytogenes on packaged, refrigerated and frozen seafood.” J Food Protection 1991;54: 524-527.

“Heavy metals found in 40 percent of protein powders tested.” Food Safety News, February 28, 2018.

Kerr K. R., Vester-Boler BM, Morris CL, et al. “Apparent total tract energy and macronutrient digestibility and fecal fermentative end-product concentrations of domestic
cats fed extruded, raw beef-based, and cooked beef-based diets.” J Anim Science 2012; 90: 515-522.

Läikkö T, Båverud V, Danielsson-Tham ML, et al. “Canine tonsillitis associated with Listeria monocytogenes.” Vet Rec 2004; 154:732.

Martinez-Anton L, Marenda M, S.M. “Firestone SM et al. Investigation of the role of campylobacter infection in suspected acute polyradiculoneuritis in dogs..” J Vet Intern
2018; 32:352–360.

Newberry C, McKnight L., Sarav M, et al. “Going gluten free: The history and nutritional implications of today’s most popular diet.” Current Gastroenterol Rep 2017; 19:54.

Parr JM, Remillard RL. “Common cofounders of dietary elimination trials contain the antigens soy, pork, and beef.” J Am An Hosp Assoc. 2014;50(5):298-304.

Pradhan AK, Li M, L Y, Kelso LC, et al. “A modified Weibull model for growth and survival of Listeria innocua and Salmonella typhimurium in chicken breasts during refrigerated and frozen storage.” Poultry Science 2012; 91(6):1482-1488.

“Popular dog food brands recalled after repeatedly testing positive for enthanasia drug.” February 18, 2018.

Ricci R, Granato A, Vascellari M, et al. “Identification of undeclared sources of animal origin in canine dry foods used in dietary elimination trials.” J Anim Physiol Anim Nutr. 2013; 97:32-38.

Simpson-Beauchamp C, Byelashov OA, Geornaras I, et al. “Fate of Listeria monocytogenes during freezing, thawing and home storage of frankfurters.” Food Microbiol 2010;.27: 144–149.

Spitze AR, Wong DL, Rogers QR, et al. “Taurine concentrations in animal feed ingredients; cooking influences taurine content.” J Anim Physiol Anim Nutr 2003: 87:

Tôrres CL, Backus RC, Fascetti AJ, et al. “Taurine status in normal dogs fed a commercial diet associated with taurine deficiency and dilated cardiomyopathy.” J Anim Physiol Anim Nutr. 2003;87: 359–372.

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