What’s All the Fuss About?
Pet owners are naturally concerned about providing the best care for their pets, and no form of care is more direct and meaningful that what we feed our animal companions. Rare but serious problems with contamination of commercial foods for dogs and cats have stimulated significant anxiety about the safety of these foods and generated increased interest in alternatives. One such alternative is a variety raw diets, often referred to as BARF (Bones and Raw Food) diets. Even some veterinarians have suggested these diets may be beneficial to our canine and feline pets. Unfortunately, there are many myths surrounding these diets, and the facts don’t support their use.
Myth 1: Dogs and cats are carnivores and evolved to eat uncooked whole prey.
Dogs have been domesticated for tens of thousands of years, and they have been eating human leftovers for the vast majority of that time. There are significant physical and genetic differences between dogs and their closest wild relative, the wolf, and the genetic evidence suggests they diverged into separate species close to 100,000 years ago. The teeth and gastrointestinal tract of dogs has adapted to the human food they have eaten for so long. We have also made many changes in our canine companions through breeding. There is little resemblance between the average Chihuahua and a wolf, and little logic to the idea that they should have the same diet.
Cats, on the other hand, have remained hunters despite their associations with humans, and their nutritional needs are closer to those of their wild ancestors. Nevertheless, they too have been much changed by human intervention, and there are still significant differences between domestic and wild cats which make a pure prey diet less than ideal.
It is also important to point out that wolves and other wild carnivores generally live longer in captivity when fed cooked commercial diets, and the nutritional advisory group for American zoos recommends these diets over raw, whole prey for captive carnivores. And while cats often do hunt and eat whole prey, they also suffer from infections, parasites, and other illnesses related to eating birds and rodents. Raw whole prey is clearly not a natural diet for dogs. And it is not at all clear that raw prey is the healthiest or optimal food even for cats or other carnivores for which it is a natural diet.
Myth 2: Uncooked food is more nutritious than cooked commercial diets.
Proponents of BARF diets sometimes claim that vitamins and other nutrients are destroyed by cooking and so raw diets are more nutritious than cooked ones. While it is true that cooking reduces the amounts of some nutrients, it also makes others more available and easier to absorb. And while cooked commercial diets are designed to have adequate levels of vital nutrients in the final product, most raw and homemade diets tested have been found to be nutritionally unbalanced or inadequate. A number of case reports have been published of pets who developed diseases of malnutrition when fed BARF or other homemade, raw diets.
Myth 3: Raw diets are safer than commercial foods.
The recent tragedy involving melamine contamination of commercial pet foods has caused much anxiety about the safety of these products. It is important to remember, however, that such events are very rare, especially considering the tens of thousands of pets eating these diets for decades. Still, if raw diets were truly safer that would be a powerful reason to consider feeding them.
Unfortunately, there are many dangers to raw diets. Raw bones are frequently part of such diets, and these often cause fractured teeth and gastrointestinal upset, and they have been responsible for deaths from tears in the stomach and intestines.
Many raw diets tested have been shown to contain potentially deadly bacteria, including Salmonella, E. coli, and Clostridium. Dogs and cats have been shown to shed these bacteria after eating raw diets, potentially exposing other pets and humans to them, and cases of illness and death from contaminated raw meat have been published. Proper handling and cooking of raw meat can greatly reduce the risk of such bacterial infections. And contrary to the claims of some BARF proponents, there is no evidence that dogs or cats are naturally protected or immune to these infectious agents.
Intestinal parasites are very common in wild carnivores, and uncooked meat is a significant source of these. One study has shown a significant increase in parasitic disease in dogs fed homemade raw diets. The facts about such risks make it clear that overall raw diets are not safer than cooked commercial diets.
Myth 4: Raw diets are healthier than processed commercial diets.
There is no evidence to support claims that dogs or cats are healthier when fed raw diets rather than balanced commercial foods. With dramatic improvements in nutrition and healthcare and the reduction of infectious disease, parasitism, and trauma as causes of death over the last few decades, our pets are living longer than ever before. Some advocates of raw diets have pointed to an increase in deaths from cancer among companion animals as evidence commercial diets are unhealthy. However, it is far more likely that the better quality of nutrition commercial diets provide has increased the lifespan of our pets, and that cancer is more common because it is a disease of aging and there are now more elderly pets than there used to be.
As already pointed out, eating raw diets increases the risk of intestinal parasites and infections. Such diets are often not nutritionally adequate or balanced and this can lead to diseases of malnutrition. Despite the claims of many proponents, there is no reason to believe BARF diets are healthier, or even as healthy, as conventional cooked diets.
Ø While there is no evidence that raw diets benefit our pets, there are clear risks to feeding them. Though there are many myths suggesting these diets are superior to cooked commercial pet foods, the facts do not support this.
Ø In addition to the risks to our pets, there are potential risks to humans from feeding raw pet diets. The Food and Drug Administration (FDA) warns that raw pet foods can increase people’s exposure to disease-causing organisms, such as Salmonell, E. coli, and intestinal parasites. This is an especially significant concern for those most vulnerable, including children, pregnant women, the elderly, and people with depressed immune systems from HIV infection or immunosuppressive drug therapy. While additional studies are being done, at this point the evidence does not support any benefit to raw diets that might outweigh the risks.
References and More Information
Chengapappa, M., et al. Prevalence of Salmonella in raw meat diets used in racing greyhounds. J Vet Diag Invest 1993;5:372-7.
Finley, R. et al. The risk of Salmonella shedding by dogs fed Salmonella-contaminated commercial raw food diets. Can Vet J 2007;8:69-75.
Food and Drug Administration, Center for Veterinary Medicine, Pet Food webpage, http://www.fda.gov/cvm/petfoods.htm
Freeman L., Michel, K., Nutritional analysis of 5 types of “Raw Food Diets.” JAVMA March, 2001;218(5): 705.
Joffe, D., Schlesinger, D. Preliminary assessment of the risk of Salmonella infection in dogs fed raw chicken diets. Can Vet J 2002;43:441-442.
Lauren , S., et al, Computer analysis of nutrient sufficiency of published home-cooked diets for dogs and cats. Proc ACVIM Forum 2005.
Nutritional Advisory Group, American Zoo and Aquarium Association, http://www.nagonline.net/husbandry_chapters.htm#W
Rahman, A., Yathiral, S., Commercial Vs. Traditional Food In Canine Health Poster/Abstract at – Waltham International Nutritional Science Symposium – Innovations in Companion Animal Nutrition Abstracts, Washington DC, USA September 15-18, 2005
Robinson JGA, Gorrel C. The oral status of a pack of foxhounds fed a “natural” diet (abstract). Proceedings. Fifth World Veterinary Dental Congress. Birmingham, England, 1997.
Weese, J. et al. Bacteriological evaluation of commercial canine and feline raw diets. Can Vet J 2005;46:513–516.
Stiver, S. et al. Septicemic salmonellosis in two cats fed a raw meat diet. J AM Anim Hosp Assoc 2003;39:538-42.
Strohmeyer, R.A., et al., Evaluation of bacterial and protozoal contamination of commercially-available raw meat diets for dogs. JAVMA 2006;228:537-542.
© Brennen McKenzie, 2008