The provision of food to our pets is an expression of affection and a symbol of the duty of care we owe to them. One thing I’ve learned from interactions on forums and Facebook groups is that you cannot ever underestimate the relationship between pets and their people. Kids, sure. But pets? Just don’t go down that path. People often react fiercely (and illogically) when it comes to discussing food for their pets. At one time, the majority of dogs and cats were fed commercially prepared foods without question. However, some pet owners have moved away from feeding commercial pet food products exclusively and more are asking questions and looking for alternatives. The 2007 pet food recall due to melamine contamination brought the issue of pet food safety to the forefront. As in any market-driven economy, there are many more alternative diets and food products available, but the dietary appropriateness, adequacy, and safety may be in question with alternative diets, especially those consisting primarily of raw meat.
BARF stands for Bones and Raw Food or Biologically Appropriate Raw Food diet. It’s also occasionally referred to as RMBD (raw meat based diet). These diets usually include uncooked ingredients derived from domesticated or wild-caught food animal species and that are fed to dogs or cats. These ingredients can include skeletal muscles, internal organs, and bones from mammals, fish, or poultry as well as uncooked eggs. The vast majority of pet foods are by-products of the human food industry.
Dogs Are Not Wolves
Adherents of BARF tell us that raw meat is an appropriate diet to feed our dogs because dogs are essentially wolves. Raw meat and bones are the major part of a wolf’s diet, along with offal such as organs, eggs, decaying material, birds with feathers – whatever they eat is obviously going to be raw. They may eat vegetables or foods left behind by humans if they are particularly hungry, but for the most part, the vegetables they consume come from the guts of the prey animals they eat. Taxonomically and phylogenetically, dogs, like wolves, are carnivores and they all belong to the order Carnivora, aptly named since most members are primarily meat consumers. Functionally however, dogs are scavenging carnivores, not obligate carnivores, and they can usually adapt quite easily to an omnivorous diet regardless of their taxonomic classification. Therefore, we could say that the concept of “evolutionary nutrition” ignores the simple fact that taxonomy and phylogeny are not necessarily destiny, nor do they predict the precise details of a species’ nutritional needs. A good example of this exception is with the giant panda, who, while possessing the same digestive system of a carnivore, is almost completely herbivorous.
The domestic dog is the most phenotypically diverse mammal on earth. Domestic dogs branched off from their wolf ancestor approximately 100,000 years ago, and artificial selection has shaped modern breeds and has been an important source of the extreme phenotypic variation present in modern-day dogs. Since then numerous anatomic and behavioural changes that have occurred as a result of dogs living with humans and sharing our food. In contrast, the modern wolf has not been exposed to 100,000 years of eating alongside humans, and therefore its nutritional needs were not altered in the same manner as dogs. To expect these different species to have the same nutritional needs is simply not substantiated via biology.
Domestic dogs exhibit many features of neoteny, which has occurred as a result of humans selecting dogs for “cute” characteristics such as large eyes, soft hair, rounder heads, smaller teeth, and floppy rather than upright ears. So their refined anatomical structures are significantly different from wolves. Of course, even if BARF advocates could demonstrate that dogs were the modern day equivalent to wolves in terms of diet, the evolutionary nutrition argument would still fail because at its heart it is nothing but a form of the naturalistic fallacy. It’s a fallacy that just because wolves get their nutrition from carcasses that raw meat is the appropriate source of food for domesticated dogs – “natural” cannot necessarily be equated with “optimal.”
BARF advocates claim that dogs have better health and less disease on these diets. Claims are even made that bones boost the immune system. Proponents of raw meat diets also claim that other benefits consist of improvement in coat and skin; elimination of breath and fecal odour; improvement in energy, behaviour, and a reduction in medical conditions including allergies, arthritis, pancreatitis, dental disease, and oddly enough, parasitism. Once again, anecdotes are not evidence, and these claimed health benefits have not undergone scientific evaluation. Dr. Mark Crislip, an infectious disease specialist with a very listenable podcast on iTunes, repeatedly reminds his listeners that the phrase “in my experience” is a dangerous expression!
Sometimes the commercial pet food industry is demonized in the same way that the Complementary Alternative Medicine industry (CAM) attacks Big Pharma. CAM veterinarians frequently attack traditional veterinary medicine with often irrational and unfounded criticisms. In addition to suggesting that conventional medicine is misguided and ineffective, CAM practitioners frequently assert that it is actively harmful, particularly vaccines and medicines. The same arguments and logical fallacies are often used to promote alternative feeding methods. For instance, homeopathic veterinarian Dr. Richard Pitcairn, who claims medicine is “unscientific,” and is obsessed with “toxins,” describes a mystical “life energy” that dogs cannot, in his opinion, get from processed food. Why is it that so many followers of homeopathy claim to be able to detect “life energy” that other people cannot? And I wonder if Pitcairn eats all his food raw as well? Dr. Pitcairn also claims that euthanized cats and dogs are routinely disposed of by veterinary hospitals to be recycled into pet food. This simply isn’t true. Veterinarian Dr. Dan Scott claims that commercial pet foods are responsible for the majority of pet diseases. So where is the proof? Where is the evidence of widespread disease that can be attributed to commercial pet food? Scott doesn’t seem to provide any but his followers are expected to take him at his word. There is no evidence that manufactured pet foods cause disease (obviously this precludes foods made in China, which have caused the death of thousands of pets). Dr. Tom Lonsdale (who was kicked out of the Australian Veterinary Association) claims that fake animal rights activists conspire with veterinarians and the commercial food industry to keep pet owners in the dark about “junk food” for pets.
Benefits Vs. Risks
There is some evidence that raw diets afforded higher levels of protein for certain species of exotic and domesticated animals, but that this is offset by other specific risks. Furthermore, nutrients that are lost during the cooking process for manufactured pet foods are supplemented to account for this.
The FDA has warned against feeding bones to dogs, as they can cause fractured teeth, intestinal perforations leading to peritonitis, and obstipation/impactions in the GI tract. Dogs can die without veterinary intervention if they cannot pass an obstruction without help. And if a dog fractures a tooth, it is likely to be a “chewing tooth” such as a large molar and not a small pre-molar. Softer bones are also great for lodging themselves in the narrow spaces between teeth and becoming food for anaerobic bacteria, thus generating periodontal disease. Cats can also choke on bones, particularly chicken bones.
There is mounting evidence of other potential harm as a result of BARF feeding. Renal failure is a common cause of death in older dogs and cats – protein is poorly metabolized by dogs with kidney failure. Most veterinary hospitals are unable to detect kidney failure until it is quite advanced, and in any case it is irreversible. Proponents of raw diets seem to ignore this common cause of death in older pets. Commercial pet foods are available for animals with renal failure or allergies to certain proteins.
We cook meat for a reason and most of us know that we have to take precautions when handling it. While dogs and cats can usually handle a larger burden of microbes in their food than humans, BARF feeders have no way of knowing whether their pets are acquiring parasites or infectious disease. The digestive systems of dogs and cats are short, acidic, and handle bacteria well. This is why they are not susceptible to Salmonella, parasites, or E.coli from tainted meat as humans are. Humans have very long digestive tracks which allow food to linger for 24 hours or more, thus allowing more time for parasites to get into their bloodstreams. The majority of dogs and cats with E.coli or Salmonella organisms may not even exhibit symptoms.
Dogs and cats will periodically shed parasites and this is a risk to children and owners who have compromised immune systems. In one study, approximately half the dogs fed a single meal of contaminated raw food shed Salmonella in their feces for up to 7 days Other bacteria that have been found in raw meat diets include E. coli and Clostridium. Dogs also shed Salmonella in their saliva, so if your dog eats raw foods with Salmonella bacteria and then licks your hands or face, the dog may be transferring bacteria to you.
In a large study conducted on 200 hundred healthy therapy dogs from Ontario and Alberta, some of whom were fed raw meat during the year, it was observed that the incidence rate of Salmonella shedding in the raw meat-fed dogs was 0.61 cases/dog-year, compared with 0.08 cases/dog-year in dogs that were not fed raw meat. Raw meat consumption was also significantly associated with shedding E. coli. One of the conclusions of the study was that dogs fed raw meat may be a risk to humans whose immune systems are not fully functioning, and should be excluded from AAI (animal assisted intervention) programmes, particularly when the programmes involve interaction with humans at high risk of infection.
An article from Phys.org entitled “Raw Meat May Not Be Enough for Cats or Tigers” found that:
“… raw meat diets met many nutrient requirements for (captive wild) cats, but there were some gaps. None of the diets contained the recommended levels of linoleic acid, the horsemeat did not provide the levels of arachidonic acid recommended for kittens, gestating females and lactating females.”
These same researchers were:
“…a bit wary” of pet owners feeding homemade raw diets. … pet owners risk exposing (domestic) cats to increased pathogens and nutrient imbalances. Pet owners often feed trimmed cuts of meat. These cuts lack fat, which is crucial in feline diets. According to the researchers, if pet owners feed raw meat diets, they will likely have to supplement it with other nutrients, including appropriate sources of fat and essential fatty acids. A high-protein diet can also change the types of microbes in the gut. The researchers write that increased protein fermentation in the bowel may lead to more “odiferous” feces, depending on the digestibility of the protein.”
Another study found that dogs fed raw chicken may be a source of contamination.
There don’t appear to be any measurable demonstrated benefits from a BARF diet, only theoretical benefits that are often based on erroneous assumptions or anecdotal observations, while there are documented risks, potential nutritional inadequacy and possible injury from raw bones. On the other hand, cooking food comes with advantages. Basically, cooking is just a method of doing some of the digesting beforehand. Ruminants ferment their food in their stomachs, and we cook ours. Do people eat raw eggs and raw meat? Yes, we do, but just because we occasionally eat raw meat doesn’t mean that it’s a particularly good idea.
The most common forms of commercial BARF diets consist of are fresh, frozen, and freeze-dried meats intended to be nutritionally complete and balanced. These diets are often formulated to meet values listed in the AAFCO Dog or Cat Food Nutrient Profiles. However, some of these foods may be labelled as intended for intermittent or supplemental feeding only, which means that they are not nutritionally complete and balanced. Traditional pet food manufacturers are regulated in that they must use ingredients that are “Generally Recognized As Safe” or GRAS. At the very minimum, canned food must contain minimum percentages of crude fat and crude protein. Commercial feeds often provide ingredients that BARF diets cannot possibly provide, such as foods for dogs or cats with renal failure and allergies. If you feed dry food it is very easily measured for consistent feeding and dogs and cats usually have solid poops that are easy to pick up. Dry food cleans teeth better than either soft or BARF food too. I wouldn’t give a dog rawhide either, because I have never been able to verify the country of origin for these products – for all I know they may originate in China as well.
The key factor is risk reduction and BARF is not exactly a low risk diet given the potential for contamination for both pets and humans. Given that dogs and cats do get foodborne illnesses there is all the more reason to cook their food beforehand. When I do give my dog and cat meat instead of commercial food, it is always pre-cooked.