Why is RAW food so popular?
Raw meat based diets (RMBD) such as the BARF diet (Biologically Appropriate Raw Food, Bones and Raw Food) began in the late 1960’s as a natural alternative to processed dog foods. Perceived improved dental and skin health, and more ‘compact’ stool, among other health claims have given further momentum to this movement. A desire to move away from processed foods and toward more whole foods makes RMBD attractive to many. However, there is little to no scientific evidence for the benefit of these diets.
What is the science behind RAW food?
There is little evidence for the benefit of RMBD. One study shows fewer ear and skin infections, and better intestinal tract health (i.e. bowel movements) on a small number of RMBD fed dogs⁸ ⁹. However, there is strong evidence for lack of nutritional adequacy ⁷ ⁸ ⁹ ¹⁰ ¹¹ (unbalanced diet) and bacterial and protozoal contamination.¹ ² ⁴ ⁵ ⁶ ⁷
What are the risks associated with feeding RAW food diets?
The risks are mostly due to pathogens, which are mostly bacteria, that are in the raw meat and not killed by cooking. Many healthy dogs eat raw food and there are no problems with people, or the dogs, getting sick. But the risks are real, and there are numerous reports of both animals and people becoming ill with preventable diseases.
- 50% of dogs eating raw food diets shed Salmonella², and there are reports of fatal Salmonella infection in cats⁴.
- Other pathogens that have been found in RAW meat diets include E. coli (including 0157:H7), extended-spectrum (resistant) E. coli, Salmonella spp., Listeria monocytogenes, Clostridium difficile, C. perfringens, C. botulinum, Campylobacter, Yersinia enterocolitica, enterotoxigenic Staphylococcus aureus, Brucella suis, Mycobacterium bovis, Toxoplasmosis, and Neospora.² ³ ⁴ ⁵ ⁶ ⁷ ⁹
Another trend seen with raw food is the type of bacteria shed; there is strong evidence that the species of bacteria shed from raw food has multiple resistance factors for antibiotics; in other words ‘superbugs’ ⁷.
- A study involving healthy dogs in the UK found that those who ate RAW meat were significantly more likely to shed multidrug resistant E. coli ³ ⁷. This type of E. coli can be fatal if an animal, or a person, is infected with it. Additionally, with increased shedding of this bacteria into the environment, the risk of bacteria ‘spreading’ resistance genes amongst themselves is increased.
Further risks include those involving malnutrition. Raw diets may be inadequately formulated and may lack essential vitamins and minerals, or may have toxic levels of vitamins or minerals. Few if any of these diets have been tested for long term use.⁷ ⁸ ⁹ ¹⁰ ¹¹
Is my dog a wolf?
The wolf has been claimed as a model for feeding RMBD food to dogs. Wolves have a decreased ability to digest carbohydrates¹⁴, which make up a large part of commercial pet foods. Dogs, however, have altered gene expression for digestibility of carbohydrates. Additionally, the lifespan of wolves in the wild (6-8 years) is much shorter than we hope for our pets.
But the poo is so small and firm!
Yes, RMDB food leads to smaller bowel movements, which are more compact and easy to dispose of. This is not necessarily correlated with better absorption. When RMBD food leads to better stool it is more likely a particular ingredient in the kibble that is to blame, rather than the kibble itself. When a dog has soft stool on RMBD, it can be due to a food allergy or a bacterial overgrowth. There is some evidence that dogs on RMBD diets have a ‘healthier’ diversity of bacteria in their gut.
How can I decrease risk?
It is NOT recommended to feed your pets RAW meat. However, if you choose to do so you can decrease risk in the following ways:
- Purchase from a reputable supplier
- Ensure the meat would be safe for human consumption
- Any RAW meat not used immediately should be kept frozen
- Meat should be defrosted in the refrigerator in a sealed container and not have contact with any other foodstuffs
- Thawed meat should be used within 48 hours
- Prevent contamination with kitchen surfaces, utensils, dishes
- Wash hands thoroughly, or use an alcohol hand sanitizer after contact with any raw meat or any surfaces, dishes or utensils that come into contact with RAW meat
- See Worms & Germs Blog for more safety information
How is feeding kibble a better thing to do for the environment?
The ingredients that go into kibble are from parts of the animal that humans are either unwilling to eat or are unsafe before processing for humans. They are highly processed (thus decreasing bacterial contamination) and rendered into kibble. Thus, ‘food’ that would otherwise be wasted is turned into kibble to feed our pets. In this way the burden on world food production for our pets is reduced, and nutrients that would otherwise be wasted are recycled.
Why is a RAW food inappropriate for an elimination diet trial?
Elimination diet trials remain our only definitive tool to diagnose food allergies in our pets. In order for an elimination diet trial to work, it is essential that the food the pet is eating does not contain any non-label proteins, or in other words, the food does not have any contamination from other proteins. In a recent study, over 60% of raw food diets had DNA from other, non-listed, proteins in them¹⁵. It is a waste of time and money to use a commercial raw food diet for an elimination diet trial in our pets at this time.
But what if I practice good hand hygiene and put my dog’s dish in the dishwasher?
Practicing good hand hygiene and cleaning your dog’s dishes will reduce contamination of pathogens. More than one study has found live pathogens in the dog dish after the dishwasher, so be aware to keep dog dishes separated regardless of cleaning. See tips for safe feeding of raw meat diets at Worms & Germs Blog or listening to the podcast Ontario Animal Health Network (episode 31-34).
Why is my veterinarian ‘against’ uncooked, unbalanced diets?
The RAW food debate has become an emotional ‘them versus us’ argument that often pits veterinarians against RAW food supporters. People want to feed their pet the best diet they can, and logic dictates that fresh food is healthier for our pets than processed food. In human medicine, science dictates that fresh prepared food is healthier for us, and that highly processed, packaged food is bad for us. So why is this not true for our pets? It may be. But we do not currently know how to easily feed a fresh prepared diet that comes near to the optimal nutrition, safety and cost of high quality kibble. We need to understand HOW to feed our pets a balanced and complete fresh food diet before it can ever replace balanced and complete kibble.
There are no studies showing the nutritional completeness of any RAW food diet. There are, however, several studies showing lack of nutritional completeness.⁸ ⁹ ¹⁰ ¹¹ ¹³ Evidence suggests there are inappropriate levels of calcium and phosphorous, as well as vitamin D, zinc, potassium and magnesium. Short term this may not impact your dog’s health, but long term it can have serious medical consequences. In growing puppies, the appropriate ratio of calcium (and vitamin D) to phosphorous is essential for normal bone growth. There is a current investigation by the FDA into the role unbalanced diets (including home cooked, raw, dehydrated) have in an increased incidence of a heart disease called dilated cardiomyopathy. These examples among many others underscore the importance of long-term balancing.
What are the facts supporting RAW food diets?
There is strong anecdotal evidence that RAW food can improve a dog’s symptoms and overall health. Dogs fed raw food have a lower rate of non-intestinal infections¹² (i.e. ear infections). When RAW food improves a dog’s symptoms (skin infections, ear infections, anal sac infections, diarrhea, vomiting, itch) it is more likely that the change from kibble (which eliminates dust, preservatives, dyes, and histamines), and/or the nature of a single
protein diet, improved the pet’s symptoms, not the fact the meat was uncooked. In fact, there is evidence that RAW proteins are more allergenic than cooked. In one study, cooking reduced the IgE sensitisation (allergic reaction) from 45-19%. There is no evidence that cooking food has a negative impact on the health of the pet fed a complete and balanced diet.
- Clark C et al. Characterization of Salmonella associated with pig ear dog treats in Canada. Journal of Clinical Microbiology. 2001 Nov (39)11: 3962-8.
- Finley et al. The risk of salmonellae shedding by dogs fed Salmonella-containing commercial raw food diets. Canadian Veterinary Journal. 2007 48(1) 69-75.
- Schmidt VM et al. Antimicrobial resistance risk factors and characterization of faecal E.coli isolated from healthy Labrador retrievers in the United Kingdom. Preventative Veterinary Medicine 2015 April 1 119; (1-2); 39-40.
- Stiver SL et al. Septicemic salmonellosis in two cats fed a raw meat diet. Journal of the American Animal Hospital Association, 2003 Nov-Dec; 39 (6): 538-42.
- O’Halloran C. et al. Tuberculosis due to Mycobacterium bovis in pet cats associated with feeding a commercial raw food diet. Journal of Feline Medicine and Surgery, 2019 May 13 epub ahead of print.
- Ketaran, K et al. Canine salmonellosis in a small animal hospital. Journal of the American Veterinary Medical Association, 1981 Nov (15); 179(10):1017-8.
- Davies, RH et al. Raw diets for dogs and cats: a review with particular reference to microbiological hazards. Journal of Small Animal Practice. 2019 60: 329-339.
- Freeman LM and Michel, KE. Evaluation of raw food diets for dogs. Journal of the American Veterinary Medical Association. 2001 218:705-709.
- Freeman et al. Current knowledge of the risks and benefits of raw meat based diets for dogs and cats. Journal of the American Veterinary Medical Association. 2013 243: 1549-1558.
- Schlesinger, DP and Joffe DJ. Raw food diets in companion animals: A critical review. Canadian Veterinary Journal. 2011 52: 50-54.
- Lennox et al. Metabolic bone disease and retinal degeneration in a kitten due to nutritional inadequacy of an all-meat diet. Journal of Feline Medicine and Surgery Open Reports 2015 (1); 1-5.
- Lefebvre et al. Evaluation of the risks of shedding salmonellae and other potential pathogens by therapy dogs fed raw diets in Ontario and Alberta. 2008 Zoonoses and Public Health (55) 470-480.
- Stockman at al. Evaluation of recipes of home prepared maintenance diets for dogs. Journal of the American Veterinary Medical Association. 2013 242: 1500-1505.
- Lyu et al. Changes in feeding habits promoted the differentiation of the composition and function of gut microbiotas between domestic dogs (Canis lupus familiaris) and gray wolves (Canis lupis). AMB Express 2018 8:123.
- Cox et al. Detection of DNA from undeclared animal species in commercial canine and feline raw meat diets using qPCR. Canadian Veterinary Journal. 2020 61 (977-984).