Is feeding a raw meat-based diet worth the health risks?

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Commercial and home-prepared raw meat-based diets (RMBDs) have grown in popularity over the past decade. Supporters of RMBDs claim they are a safe, natural way to promote animal wellness and boast about the nutritional superiority to common diets. These claims are made without long-term supportive evidence and largely ignore the potentially life-threatening consequences to pets and their human caregivers when contaminated RMBDs are fed. The American Animal Hospital Association,¹ American Veterinary Medical Association (AVMA),² and Canadian Veterinary Medical Association³ have adopted statements discouraging the inclusion of raw or undercooked animal-source protein in dog and cat diets.

Several studies have revealed important concerns about nutritional imbalances when RMBDs are not formulated properly, health risks to animals, and public health concerns. Manufacturers of raw or cooked commercial pet foods employ a wide variety of quality-control standards.

A 2001 US study⁴ showed the home-prepared and commercial RMBDs tested had multiple nutritional imbalances, including a calcium-to-phosphorus ratio of 0.20, vitamin A and E concentrations below the minimum detectable value, and a vitamin D concentration nearly twice the AAFCO maximum amount. A case report showed⁵ a growing dog being fed an RMBD resulted in vitamin D–dependent rickets type I and nutritional secondary hyperparathyroidism. In a recent study in Europe,⁶ investigators calculated amounts of 12 nutrients (eg, calcium, phosphorus, and vitamin A) for 95 homemade RMBDs being fed to dogs, as reported by the owners. In that study, (60%) diets had major nutritional imbalances.

Raw meats are frequently contaminated with microorganisms such as E coli, Salmonella spp, Clostridium spp, Campylobacter spp, Listeria spp, and parasites such as T gondii. Several studies^7-10 have found that dogs eating RMBDs are at risk for shedding Salmonella spp in their feces. The environmental contamination caused by the shedding of these organisms after pets ingest them raises a risk for infection of humans. A recent study¹¹ revealed a Salmonella prevalence rate of 21% for 166 commercial RMBDs, and 18 Salmonella serotypes isolated from those samples were resistant to 12 of 16 antimicrobials tested.

To ensure the safety of other pets and veterinary staff, authors of an article in the Journal of the AVMA¹² recommend veterinarians establish procedures for pets that eat RMBDs because of the risk of bacterial and parasitic contamination. They also recommend counseling owners who feed a RMBD on the risk to themselves and documenting this conversation in the medical record. These nutritional deficiencies in RMBDs can lead to long-term complications if not detected early.

Additional studies are needed to provide information about the long-term health effects of RMBDs for dogs and cats. In the absence of these reported studies, an animal eating a home-prepared diet should undergo an annual physical examination and comprehensive health screening.¹² This includes a serum biochemical analysis (with thyroxine concentrations), hematologic analysis, and urinalysis.

Caitlee Callahan is a 2023 PharmD candidate at the University of Connecticut

References

1. Raw protein diet. American Animal Hospital Association. October 2011. Accessed May 9, 2023. https://www.aaha.org/about-aaha/aaha-position-statements/raw-protein-diet
2. Raw or undercooked animal-source protein in cat and dog diets. American Veterinary Medical Association. Accessed May 9, 2023. https://www.avma.org/resources-tools/avma-policies/raw-or-undercooked-animal-source-protein-cat-and-dog-diets
3. Raw meat-based diets for pets. Canadian Veterinary Medical Association. July 3, 2018. Accessed May 9, 2023. https://www.canadianveterinarians.net/policy-and-outreach/position-statements/statements/raw-meat-based-diets-for-pets
4. Freeman LM, Michel KE. Evaluation of raw food diets for dogs. J Am Vet Med Assoc. 2001 Mar 1;218(5):705-9. doi: 10.2460/javma.2001.218.705. Erratum in: J Am Vet Med Assoc 2001 May 15;218(10):1582.
5. Taylor MB, Geiger DA, Saker KE, Larson MM. Diffuse osteopenia and myelopathy in a puppy fed a diet composed of an organic premix and raw ground beef. J Am Vet Med Assoc. 2009 Apr 15;234(8):1041-8. doi: 10.2460/javma.234.8.1041.
6. Dillitzer N, Becker N, Kienzle E. Intake of minerals, trace elements and vitamins in bone and raw food rations in adult dogs. Br J Nutr. 2011 Oct;106 Suppl 1:S53-6. doi: 10.1017/S0007114511002765.
7. Joffe DJ, Schlesinger DP. Preliminary assessment of the risk of Salmonella infection in dogs fed raw chicken diets. Can Vet J. 2002 Jun;43(6):441-2.
8. Leonard EK, Pearl DL, Finley RL, et al. Evaluation of pet-related management factors and the risk of Salmonella spp. carriage in pet dogs from volunteer households in Ontario (2005-2006). Zoonoses Public Health. 2011 Mar;58(2):140-9. doi: 10.1111/j.1863-2378.2009.01320.x.
9. Lefebvre SL, Reid-Smith R, Boerlin P, Weese JS. Evaluation of the risks of shedding Salmonellae and other potential pathogens by therapy dogs fed raw diets in Ontario and Alberta. Zoonoses Public Health. 2008 Oct;55(8-10):470-80. doi: 10.1111/j.1863-2378.2008.01145.x.
10. Finley R, Ribble C, Aramini J, et al. The risk of salmonellae shedding by dogs fed Salmonella-contaminated commercial raw food diets. Can Vet J. 2007 Jan;48(1):69-75.
11. Finley R, Reid-Smith R, Ribble C, Popa M, Vandermeer M, Aramini J. The occurrence and antimicrobial susceptibility of salmonellae isolated from commercially available canine raw food diets in three Canadian cities. Zoonoses Public Health. 2008 Oct;55(8-10):462-9. doi: 10.1111/j.1863-2378.2008.01147.x.
12. 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;243(11):1549-1558. doi:10.2460/javma.243.11.1549