Raw diets are becoming increasingly popular within the pet community. There are both homemade and commercially manufactured options available for consumers. These diets typically include some combination of muscle meat, organ meat, eggs, seafood, bones, and vegetables. Some of the benefits that raw food diets claim to provide include: longevity and overall good health, improved oral health, and resolution of gastrointestinal and dermatological diseases. Another reason people choose raw food diets for their pet(s) is to fall more in line with an ancestral diet.
There are some studies that have shown that raw diets are more digestible than standard commercial options. However, there is no scientific evidence for any of the other proposed benefits of raw diets, including long term health benefits.
On the other hand, there are multiple documented risks of feeding raw diets to our pets. The primary concern is in regards to nutritional adequacy. Many raw diets are found to have either excessive or deficient amounts of essential nutrients. There are very few commercially available raw diets that have undergone feeding tests for nutritional adequacy. Many raw diets have been found to be incomplete or unbalanced, mainly in regards to calcium/phosphorus ratios as well as vitamins and minerals such as copper, zinc and Vitamin A. Many of the raw diets studied were found to be too high in fat, leading to an increased risk in obesity and are contraindicated for some individual pets. In cats, if raw food is not supplemented with taurine, there is a high risk for heart disease.
Another major concern with raw diets is the risk for pathogenic contamination (bacteria and parasites). In diets that include bones, there is risk of fractured teeth and gastrointestinal perforation. There have been many recalls of raw foods due to contamination, despite the use of high-pressure pasteurization. The main pathogens of concern found within these diets are Salmonella, E. coli and Campylobacter. While pets can often be more resistant to becoming sick from these pathogens, there are many documented cases where pets are affected negatively by these bacteria. Additionally, a high risk of infection is introduced to the humans who are preparing the raw food who are also further exposed by living with the pets that will shed the pathogens in their feces for weeks after.
Many raw diets are marketed as “Ancestral diets,” – or feeding what wolves and big cats would eat in the wild. While dogs and cats rely heavily on animal-derived nutrients, their non-domesticated relatives have a very different life compared to our house pets. A recent study1 investigating differences in the genome of dogs and wolves found several dissimilarities related to genes involved in starch digestion and fat metabolism. This study found that domesticated dogs have metabolically evolved to a more omnivorous/carnivorous combination diet compared to their carnivorous wild relatives. Diets that may be suitable to support our pets’ wild relatives who have relatively shorter life spans and more intensive reproductive activity may not be optimal for supporting longevity and health in domesticated animals and pets.
Most, but not all, healthy adult animals will tolerate a raw food diet. However, since these diets are not always nutritionally sufficient and can cause infections in pets (and more so in humans), these diets are not recommended by the veterinary community in most situations.
1. Axelsson E, Ratnakumar A, Arendt M-L, et al. The genomic signature of dog domestication reveals adaptation to a starch-rich diet. Nature. 2013;495(7441):360–364.