Journal Scan: Nutrition matters: Pondering raw meat-based diets
A review of the reasons these diets are so popular and a discussion of areas where additional research is needed.
Why they did it
Despite recommendations from leading veterinary organizations that discourage the feeding of raw meat-based diets, the practice continues to increase in popularity and generate controversy. There is a lack of sound scientific evidence regarding the risks and benefits of these diets. The authors of this article review the current literature on the subject, review the reasons why these diets are so popular, and highlight areas where additional research is needed.
Commercial raw meat-based diets come in a variety of formulations including fresh, fresh frozen, and freeze dried. Some commercial diets are developed to meet the specifications established by the Association of American Feed Control Ofﬁcials (AAFCO), but there can be a great deal of variability in quality control measures. Other diets are intended for supplemental or intermittent feeding only and are, therefore, not nutritionally balanced. The authors note that proponents of raw meat-based diets claim that these diets provide superior health benefits, but “[m]any claims of beneﬁts are largely unproven and not based on scientiﬁc evidence.” Despite this, pet owners perceive that they are feeding their pet a “natural” diet and may also choose to feed a home-prepared raw meat-based diet. The authors also point out that distrust of large pet food manufacturers, especially in light of recent pet food recalls, may also motivate owners to feed raw meat-based diets.
The authors discuss another aspect of the raw meat-based diet controversy that centers on the effects of cooking. Some studies have shown that when compared to cooked diets, raw meat-based diets may have a higher energy and macronutrient digestibility, but the clinical benefits of this are not well-understood. The effect of heat, pressure, and water content may affect proteins and amino acids in the diet, increasing the bioavailability of some nutrients and decreasing the bioavailability of others.
In addition to concerns about nutritional imbalances, the authors discuss possible health risks associated with feeding raw meat-based diets. These include contamination with pathogens such as Salmonella species and Escherichia coli that are not destroyed even in diets that are frozen or freeze-dried. Not only does this contamination endanger the pet, but it poses a risk to family members as well. In addition, raw meat-based diets that contain bones can pose a risk of intestinal obstruction or perforation.
Feeding raw meat-based diets (including pet treats such as pig ears, rawhides, or bully sticks) can pose health risks to pets as well as their caregivers, even for diets formulated according to AAFCO specifications. Veterinarians should educate clients about these risks, particularly when there are immunocompromised, young, elderly, or pregnant caregivers involved. Further studies are needed to provide a better understanding of the long-term consequences of feeding raw meat-based diets, and owner education will be critical in ensuring the health and safety of all concerned.
Freeman LM, Chandler ML, Hamper BA, et al. Current knowledge about the risks and benefits of raw meat-based diets for dogs and cats. J Am Vet Med Assoc 2013;243:1549-1558.
Link to abstract: http://avmajournals.avma.org/doi/abs/10.2460/javma.243.11.1549