A nice new review of the evidence concerning raw meat-based diets appears in the most recent issue of the Journal of the American Veterinary Medical Association.
Freeman LM, Chandler ML, Hamper BA, Weeth LP. Current knowledge about the risks and benefits of raw meat-based diets for dogs and cats. J Am Vet Med Assoc. 2013 Dec 1;243(11):1549-58.
The article reviews many of the studies looking at basic issues such as the effects of cooking on digestibility and the risks of nutritional inadequacy and infectious organisms in raw diets. I have previously written about a number of these studies. The bottom line, which is consistent with my own understanding, is that there are no proven benefits of feeding raw diets, a few small but well-established risks, and little direct research evidence involving comparisons of pets fed different kinds of diets. Here are some of the conclusions of this review:
Proponents of RMBDs claim that they are a safe and natural way to promote animal wellness; these claims are made without long-term supportive evidence and largely ignore the potential life-threatening consequences to pets and their human caregivers when contaminated RMBDs are fed.
Pets often consume RMBDs without developing any health problems, but sometimes even healthy adult dogs and cats can develop adverse effects, ranging from relatively benign effects (eg, increased colonic fermentation and gas production with higher protein intakes) to more overtly life-threatening concerns (eg, higher fat diet fed to an animal with a history of pancreatitis), as a result of consumption of these diets. Additionally, raw meat has an inherent risk of bacterial and parasitic contamination, and animals that consume RMBDs may pose a risk to other pets and people in the household and surrounding community, including veterinarians and veterinary support staff.
If a commercial RMBD is formulated to meet AAFCO nutrient guidelines…there should be minimal risk of nutritional inadequacy. However, few manufacturers of raw diets conduct AAFCO feeding trials or digestibility…Thus, the assumption that these diets are truly complete and balanced for long-term feeding relies heavily on the expertise of the individual formulating the original recipe…
If these diets are manufactured in accordance with current FDA regulations for handling of foods and requirements for microbial testing during food manufacturing and storage, there should be minimal risk of exposure to foodborne pathogens. However, variation in quality-control testing practices or inadequate testing conducted by a manufacturer of a raw food may allow for introduction of pathogens into pet-owning households.
On the basis of published diet reviews, most home-prepared diets (both raw and cooked) are deficient in 1 or more essential fatty acids, vitamins, or minerals or a combination thereof. Although the perceived benefits of home-prepared diets may be reinforced daily to owners through a pet’s appetite or coat quality, nutrient deficiencies and excesses in adult animals are insidious and can lead to long-term complications if not detected and corrected.