Researchers review existing evidence on raw food diets
NORTH GRAFTON, Mass. (January 2, 2014) – Feeding pets raw meat has become increasingly popular, especially with the availability of more commercial products and home-prepared recipes, but it’s a polarizing issue. Enthusiasts claim it’s a healthier, more natural diet for dogs and cats, yet the American Animal Hospital Association and American Veterinary Medical Association have discouraged the inclusion of raw and undercooked meats in pet food, citing a potential for food-borne illness for both the pet and humans who are in contact with the pet.
The risks for food-borne illness with raw meat are real but other studies suggest additional concerns with these diets. In a recently published article in the Journal of American Veterinary Medicine, a group of researchers compared the perceptions of raw meat-based diets (RMBD) against existing evidence to help separate fact from commonly held beliefs.
“In our culture, providing food is often viewed as a form of love and that is true for our pets,” said Lisa Freeman, D.V.M., Ph.D., the paper’s lead author and a board-certified veterinary nutritionist and faculty member at the Cummings School of Veterinary Medicine at Tufts University. “Pet nutrition decisions are often made from the heart and with the best intentions, but it’s essential to look at what the evidence tells us about the benefits and safety of a certain diet. This is especially important for diets that include raw meat and the bottom line is that the existing research shows that the risks outweigh any minimal benefits.”
A popular notion is that RMBDs provide all the nutrients a dog or cat needs in the correct balance. But at least two publications have shown that RMBDs have a high risk for nutritional deficiencies and excesses. This is especially true for home-prepared RMBDs, as with any home-prepared diet, but is also a risk for commercial RMBDs.
One difference of RMBD that does appear to be true from the results of three studies is a modest increase in digestibility compared to some commercial foods, ranging from about 5-14 percent. It is unclear, however, whether this small increase translates into any health benefits and, at this time, none have been proven.
Another idea is that feeding cats and dogs raw meat is that it mimics what their undomesticated ancestors ate in the wild. However, recent research shows that some of the changes in digestion between wolves and dogs were a crucial step in the early domestication of dogs. Wolves in the wild, which typically only live for a few years, eat foods that are not optimal for pets that we hope will live long and healthy lives, the authors note.
RMBDs and food safety concerns
Raw meat—whether sold for human consumption or as part of home-prepared or commercially sold RMBDs—can be contaminated with a variety of pathogens including Salmonella, E coli, and Clostridium, among others. Although other forms of commercial pet foods are also susceptible to contamination with Salmonella and other bacteria, studies have shown that this occurs at much lower rate than for the commercial and home-prepared raw meat diets.
For example, one study found that up to 48 percent of commercial RMBDs tested were contaminated with Salmonella, and while the rate of contamination of home-prepared RBMD is unknown, another study found that eight of 10 home-prepared raw chicken-based diets were contaminated with the bacteria. A recently released study, which was not reviewed for the JAVMA article, found that 16 percent of RMBD samples were contaminated with Listeria.
While RMBD proponents claim that the animals will not get sick from contaminated diets, there are several scientific papers documenting illness or even death of animals from these pathogens. If bones are included in the recipe (whether raw or cooked), it can cause other health risks such as fractured teeth and obstructions or perforations of the gastrointestinal tract.
“We advise pet owners to talk with their veterinarian or a veterinary nutritionist boarded by the American College of Veterinary Nutrition about nutrition for their pets, and anyone considering including raw meat in a pet’s diet to review the scientific evidence,” said Dr. Freeman.
Freeman, L.M., Chandler, M.L., Hamper, B.A., Weeth, L.P.. Current knowledge about the risks and benefits of raw meat-based diets for dogs and cats. Journal of the American Veterinary Medical Association. doi: 10.2460/javma.243.11.1549
About the Cummings School of Veterinary Medicine at Tufts University
Founded in 1978 in North Grafton, Mass., Cummings School of Veterinary Medicine at Tufts University is internationally esteemed for academic programs that impact society and the practice of veterinary medicine; three hospitals and four clinics that combined log more than 80,000 animal cases each year; and groundbreaking research that benefits animal, public, and environmental health.