To be honest I hadn't thought all that much about the relative merits of feeding dogs diets based on raw animal products and bones in comparison to good-quality commercial kibble. However, I recently received a note which got me thinking about it. The note came from a woman named Susan who lives in California and it read in part:
After my two kids went away to college I began to miss having children around to mother, so I arranged to be a foster parent for two young boys. Then one of them, Edmund, got sick. He had a high fever, severe stomach pains, and dreadful diarrhea, so I rushed him to the hospital emergency ward. The doctor's diagnosis indicated that he had salmonella. Since he is a foster child, the hospital contacted Child Welfare, and since salmonella is a food related illness they contacted the Health Department who came to examine my house. They checked out the cleanliness of the kitchen and asked questions about how I prepared food. Then they looked into my freezer and noticed the frozen packages of dog food. I feed my Labrador Retriever, Napoleon, one of those BARF kind of diets [an acronym for Bones and Raw Food] which I buy commercially. It's supposed to be healthier than feeding him kibble. They took a couple of packets of his food and had them lab tested and both of them showed evidence of salmonella. Edmund always liked to feed Napoleon and the Health Department people told me that he could have contracted the salmonella from touching the raw food and then later touching his mouth. Edmund also likes to play with Napoleon, touching his face and mouth and that sort of thing and sometimes even kissing him on the face, and that could have transferred the salmonella to him. In any event Child Welfare told me that for the safety of the kids I had to stop feeding my dog a diet based on raw animal products or they would not allow me to keep my foster children.
Inspired by this communication I decided to look into what was known about the safety of dog diets based on raw animal products. I first consulted a few websites which advocate this kind of diet. Most of these diets consist of raw muscle meat, bones, fat, organ meat and some vegetable matter. The rationale for this kind of feeding schedule is that "A biologically appropriate diet for a dog is one that consists of raw whole foods similar to those eaten by the dog's wild ancestors." This kind of statement is accompanied by suggestions that such a diet will provide maximum health for a dog while kibble based diets "cause innumerable health problems". Some of the claims are quite lyrical such as "Eating bones for a dog is a joyous experience. It is so enjoyed by dogs that it actually of itself boosts their immune system." Unfortunately, there are no references to scientific studies to support any of these claims.
I next checked to see what the major veterinary organizations had to say about the raw diet. What I found suggested a universal consensus among veterinarians that raw animal products were unsafe and that cooking was the best way to rid the foods of pathogens. Typical of this is a report by the American Veterinary Medical Association (AVMA) [click here to see that report].
Perhaps the most damning evidence comes from the US Food and Drug Administration (FDA). The FDA Center for Veterinary Medicine tested over 1000 samples of pet food for bacteria that can cause foodborne illnesses. They were specifically interested in the bacteria which causes salmonella and for L. monocytogenes which cause listeria. Their results were quite clear. Salmonella appeared in 7.6% of the samples of raw food (that's one out of every 13 samples tested) and the bacteria for listeria was more than twice as likely to be present, totaling 16% of the samples tested (which is approximately one out of every seven samples). These bacteria did not appear in any of the samples of other dog food tested whether it was dry dog food, semi-moist dog food, or jerky type treats — that is 0% of the other samples. (You can read more about this if you click here).
Given what appears to be scientific condemnation of a raw animal product-based diet for dogs what is the rationale that dog owners use for feeding their dog this kind of diet? A recent research report from a team headed by Stuart Morgan at the Virginia-Maryland College of Veterinary Medicine at Virginia Polytechnic Institute and State University in Blacksburg Virginia sheds some light on this issue. In a survey which measured owners responses for 3339 dogs they found that those who were feeding their dogs on a raw animal product diet claimed that they were doing so out of concern about the safety, quality, or nutritional value of commercial foods (67.3%), because of the belief that feeding a raw animal product diet is healthier (77.4%), because it is more natural (71.2%), to improve their dog's immune system (65.7%) or to improve their skin or coat (67.5%).
In light of their expressed health concerns for the health of their pets, one might expect that the dog owners who feed their dogs on raw animal product diets would be taking their dogs to the veterinarian more often and relying more strongly on veterinary advice. However here is where there is a major contradiction. The data shows that those who feed their dogs on these raw animal product diets tend to take their dogs to the veterinarian somewhat less frequently and when asked whether they trusted veterinarian's as a source of information about pet nutrition were less likely to do so (only 12.7% of owners who feed raw diet trust veterinarians "very much" as opposed to 54.5% of those owners who do not use the raw diet). In what seems like a further confirmation of their distrust of veterinary science, those who feed their dogs a raw animal product diet seem to have less confidence in the beneficial effects of vaccination, parasite prevention or screening for things such as heart worm.
As a psychologist and as a scientist I find these data to be puzzling and disturbing. With a strong body of scientific data suggesting that simple act of cooking a dog's food will make it safer for both the dog and the humans living in the household, a substantial number of people still insist upon feeding their dogs a raw animal product diet. Despite the fact that veterinarians recommend against such a diet the dog owners who base their dogs feeding on raw animal products still claim in an overwhelming majority that they are doing so for the health of their dogs. Perhaps these dog owners should reconsider their choice, if not merely for the health of the dog in their family, then perhaps for the health of the children who live with those dogs lest they find themselves in the same situation that Susan and Edmund did.
Stanley Coren is the author of many books including: Gods, Ghosts and Black Dogs; The Wisdom of Dogs; Do Dogs Dream? Born to Bark; The Modern Dog; Why Do Dogs Have Wet Noses? The Pawprints of History; How Dogs Think; How To Speak Dog; Why We Love the Dogs We Do; What Do Dogs Know? The Intelligence of Dogs; Why Does My Dog Act That Way? Understanding Dogs for Dummies; Sleep Thieves; The Left-hander Syndrome
Copyright SC Psychological Enterprises Ltd. May not be reprinted or reposted without permission
AVMA. (2012). Raw or undercooked animal-source protein in cat and dog diets. Available at https:// www.avma.org/KB/Policies/ Pages/Raw-or-Undercooked-Animal-Source-Protein-in-Cat-and-Dog-Diets.aspx
FDA. (2016). Get the facts! Raw pet food diets can be dangerous to you and your pet. Available at http://www.fda.gov/AnimalVeterinary/ResourcesforYou/AnimalHealthLiteracy/ucm373757.htm
Stewart K. Morgan, Susan Willis and Megan L. Shepherd (2017). Survey of owner motivations and veterinary input of owners feeding diets containing raw animal products. PeerJ, DOI 10.7717/peerj.3031