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Raw Meat and Bone Diets for Dogs: It’s Enough to Make You BARF

Some of the most rewarding interactions we have with our pets involve food. Most dogs respond with gratifying enthusiasm to being fed, and this activity is an important part of the human-animal bond. Providing food is also part of the parent/child dynamic that in many ways characterizes our relationships with our pets. Giving food is an expression of affection and a symbol of our duty of care to our pets.

Because of these emotional resonances, pet owners are often very concerned about giving their pets the “right” food to maintain health and, if possible, to prevent or treat disease. This has allowed the development of a large, and profitable commercial pet food industry that aggressively markets diets with health-related claims. This industry resembles in some ways the pharmaceutical industry. It is regulated by the FDA, and also by individual states, according to a somewhat Byzantine set of standards established by the FFDCA (the guiding document governing the FDA) and by the Association of American Feed Control Officials (AAFCO), a private organization made up primarily of state and federal feed control officials. Thanks to this regulatory structure, imperfect though it is, there is a good deal of solid science and research behind the products and claims the industry produces.

Like all for-profit concerns, the pet food industry also has its share of flaws. Some of these are relatively subtle, such as the probably unavoidable tendency for industry-funded research to come up with findings favorable to the funder’s products. Others are more serious, including rare but devastating instances of malfeasance. One example of the latter is the incident in 2007 in which melamine was substituted for wheat gluten as a protein source in pet food manufacturing, leading to the deaths of hundreds, possibly thousands of pets who ate contaminated commercial foods.

And like “Big Pharma,” the pet food industry is often demonized by those who wish to promote unscientific or alternative veterinary medical treatments or theories. Anyone who has ever accepted a dime in research funding or a bagel at a conference (with or without cream cheese) from a pet food company is automatically an industry lackey whose opinion is worthless regardless of their credentials or expertise. This demonization of the pet food manufacturers is often used as a marketing tool for alternative nutritional theories and products.

One of the most popular unscientific notions sold to pet owners these days is that of feeding diets based on raw meat, typified by the BARF diet. According to the a leading proponent of this idea, Dr. Ian Billinghurst, BARF stands for Bones and Raw Foods or Biologically Appropriate Foods (though I confess other interpretations have occurred to me). Raw diets are frequently recommended by veterinarians and other who practice homeopathy, “holistic” veterinary medicine, and other forms of CAM. This is not surprising since, as you will see, the arguments and types of reasoning used to promote the BARF concept are also commonly used to defend other forms of alternative veterinary medicine. Let’s take a look at the arguments some BARF proponents make for this diet.

Dogs are Wolves

Dr. Billingurst refers to the principle behind the BARF diet as “evolutionary nutrition.”

“It is now generally agreed that the ancestor of the modern dog is the wolf…[the] process of domestication where our ancestors removed the ‘wildness’ from the wolf, involved thousands of years of selective breeding…In this process, our ancestors produced hundreds of ‘different looking wolves’…our ancestors made only two basic changes to the wolf. They changed the wolf’s appearance and they changed its mind. What they did not change, was the basic internal workings or physiology of the wolf…As a result, the basic workings or physiology of modern dogs is no different or very little different to their ancestor the wolf…The basic environment which the modern dog requires in terms of food and exercise is exactly the same as it was (and still is) for the wolf.”

Having established that, despite appearances, dogs are essentially wolves, Dr. Billinghurst goes on to describe the wolf diet.

Raw bones with meat are a major part of their diet… They eat offal such as liver and heart. They eat raw eggs. They eat decaying material…They eat a wide variety of foodstuffs. Insects, bark, soil, birds – complete with their tiny bones and feathers – whatever. Every meal they eat is totally raw. Not one skerrick of it is cooked. Ever. They eat vegetables including herbs, from the gut of their prey. This vegetable material is raw, totally crushed and partly digested. They eat feces. A wolf’s diet contain almost no grains… For a wolf – not one single meal consists of dry dog food. They don’t eat canned dog food either.

Finally, he makes the connection between this version of canine natural history and the feeding of pet dogs.

How do you feed a dog properly? You feed it the diet that it evolved to eat. It’s [sic] evolutionary diet. A Biologically Appropriate Raw Food diet. A BARF diet…A biologically appropriate diet for a dog is one that consists of raw whole foods similar to those eaten by the dogs’ wild ancestors. The food fed must contain the same balance and type of ingredients as consumed by those wild ancestors…Please note that modern dogs of any breed are not only capable of eating the food of their wild ancestors, but actually require it for maximum health. This is because their basic physiology has changed very little with domestication despite obvious and dramatic changes in their current physical appearance and mindset…

Certainly a clear, simple, and pretty persuasive argument on the face of it. Taxonomically and phylogenetically, dogs are carnivores and their ancestors ate live prey and carrion, so they must be designed for a diet as close as reasonably possible to that for which they were designed by evolution.

Some raw diet advocates extend this basic argument by claiming that the domestic dog’s gastrointestinal tract is anatomically identical to that of the wolf and so the same dietary needs can be assumed. Others contribute additional arguments in favor of raw foods, such as the well-known homeopathic and holistic veterinarian Dr. Richard Pitcairn:

“All processed pet foods…are missing something that seems to me to be the most important “nutrient” of all. This key ingredient is practically ignored by nutritional scientists, but we can sense it when it’s there. It is a quality found only in freshly grown, uncooked whole foods: Life energy!1

But while there are variations on the theme, and there are frequent and often bitter arguments over precisely which ingredients are best, and in what form or proportion, the basic “evolutionary nutrition” argument is advanced by all proponents of raw diets.

Processed Commercial Diets are Unhealthy

The other major component to the argument for raw diets is that the commercial diets most of us feed our dogs are inadequate, and possibly outright unhealthy. According to Dr. Billinghurst’s web site,

“as a practicing veterinary surgeon, I constantly see the enormous difference in health between pets raised on commercial pet food compared to those raised on a biologically appropriate raw food diet. I see the enormous change for good in the health of pets switched from cooked to a raw whole food diet…Most degenerative disease processes in pet animals are the direct result of a lifetime being fed cooked and/or processed foods…”

He goes on to claim that the nutritional deficiency diseases seen in the early 20th century, when most pets were fed table scraps, were simple and easily treated, but thanks to processed foods these have been replaced by “vast array of complex and insidious degenerative diseases which now afflict our pets and fill our textbooks and waiting rooms.” He further claims that,

“Processed pet foods contain barely adequate levels of the known vitamins…Many contain biologically inappropriate antioxidants, enormous levels of refined sugars and masses of salt together with other chemicals used as colorings and flavorings. This chemical cocktail is a lethal brew which is a major factor in producing the epidemic of degenerative disease leading to the early death and suffering we see in pet animals fed such rubbish, including cancer, arthritis and a range of allergies and auto immune diseases…Cooking renders these products biologically inappropriate in a fundamental way…The vast majority of these products are based on cooked grains. This makes them biologically inappropriate. At no time in their evolutionary history (except in the last 50 to 150 years) have cats and dogs been subjected to cooked grain in any amount, and certainly not as the basis of their diet.”

Commercial foods are also denigrated for a variety of supposedly dangerous ingredients, including (according to Dr. Pitcairn):

Toxic products from spoiled foodstuffs
Drug residues
Hormone levels comparable to amounts that have produced cancer in laboratory animals
Artificial colors, flavors, and preservatives, all of which he claims are responsible for an epidemic of cancer and degenerative diseases
And even euthanized dogs and cats, which he claims “are routinely rendered by veterinary hospitals or shelters and recycled into pet food.”1

Cancer, arthritis, allergies, autoimmune disease, and many other conditions are frequently claimed to be the result of eating commercial pet foods. But, of course, proponents of raw diets don’t always limit their critique of commercial foods to claims about nutrition and health which could be empirically examined. Some also paint commercial pet food manufacturers as villains killing pets for profit and veterinarians as their willing, or at least duped, accomplices. A blog entry on Dr. Billinghursts’s website asks,

What is the primary motive of kibble manufactures? Is it profit or nutritional value? … The inferior quality and poor utilization of ingredients is masked by the addition of heat, flavor enhancers, and harmful fat sprays. The kibble manufactures are aware of the potential dangers and potential harm to our dogs but it all boils down to producing an inexpensive product that can sustain and maintain the life of our dogs…for the kibble manufactures it all boils down to profit with a capital P.

Another proponent of raw diets, Dr. Tom Lonsdale, claims he is

selling plenty of his book Raw Meaty Bones in the US but the Australian media seems to have blacked [sic] him out because the multinational pet food companies don’t want their dodgy doggy tucker exposed [web article 1]…Natural pet food is cheaper, pets live healthier longer lives, vet bills reduce [sic] and the environment gets a better deal. Except for the artificial pet food companies and their veterinary allies it’s a win, win, win situation…junk food is responsible for the majority of pet diseases there are both upstream and downstream implications worth $billions. Upstream those that run the systems – pet-food makers, veterinary profession, veterinary schools, animal welfare bodies, governments, retailers, and consumers — conspire to maintain the racket… The full extent of the junk pet-food fraud may never be fully known. [web article 2]

Some Inconvenient Truths

Now let’s have a look at the problems with this raw dog food marketing propaganda. To begin with, the concept of “evolutionary nutrition” ignores the simple fact that taxonomy and phylogeny are not destiny, nor do they reliably predict the specific details of a species’ biology, including its nutritional needs. Sure, dogs are in the order Carnivora, but so are giant pandas, which are almost exclusively herbivorous. Functionally, dogs are omnivores or facultative carnivores, not obligate carnivores, and they are well-suited to an omnivorous diet regardless of their taxonomic classification or ancestry.

Domestic dogs did branch off from a wolf ancestor, and current DNA evidence suggests this occurred some 100,000-135,000 years ago.2,3 Though the data are unclear as to what morphologic or ecological changes might have occurred following this initial divergence, and while it is likely that there was much ongoing genetic exchange between dogs and wolves even after they diverged, it is still the case that dogs have not been wolves for a very long time. However, a distinct phenotypic divergence of dogs and wolves followed the development of more sedentary agricultural habits by many human groups some 10-15,000 years ago, which placed new selection pressures on our canines companions.31 Since then numerous anatomic and behavioral changes that have occurred first as a result of living with humans and sharing our food. And even more dramatic changes have been wrought on dogs in the last about 3000 years as a consequence of intensive selective breeding. Domestic dogs exhibit many features of neoteny, the retention of juvenile characteristics into adulthood. They have smaller and less robust skulls and dentition, and numerous features of their skeleton, GI tract, and other anatomic structures are significantly different from wolves. 4-6

Of course, anatomy does not always correlate with function anyway. All humans have essentially the same GI tract from an anatomical perspective, but when someone who is lactose intolerant chugs a glass of milk, he or she may be treated to a visceral demonstration of the fact that anatomy doesn’t necessarily predict function. But in the case of dogs and wolves, the claim that they are anatomically identical with respect to what is an appropriate diet is simply not true. If you try to picture a pack of Chihuahuas bringing down and savaging an elk, the impact of thousands of years of artificial selection is obvious. Other breeds may be more like wolves in appearance, but they are none of them truly wolves. Dogs have lived with humans, eaten our table scraps, and been intensively bred for features we desire, none of which is likely to make them ideally designed for the diet of a wolf.

Of course, even if BARF advocates could demonstrate that dogs were functionally 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.

The average life expectancy of wolves in the wild is considerably lower than that of captive wolves, and disease, parasitism, and malnutrition are important factors in the mortality of wild populations.7-9 Captive wolves live longest and are healthiest when fed — guess what? — commercial dog food! This is the recommendation of the leading specialists in captive wolf husbandry and medicine, and it is largely the result of evidence that the previous practice of feeding raw meat based diets to captive wolves led to poorer quality nutrition and health than the current practices. Certainly, raw meat and bones are often used as enrichment items or bait for husbandry purposes, but always with an awareness of the risks they pose, and never as the primary diet. 10-12

BARF proponents persistently confound ingredients with nutrients. They imagine that because wild canids get their nutrients from raw whole carcasses that this must be the only appropriate source of nutrition for all canids, including domestic dogs despite the fact they have been eating our cooked leftovers for tens of thousands of years. This is contradicted, however, by extensive research in canine nutrition and by the generations of dogs who have lived long, healthy lives eating commercial pet foods.

Which leads to the second pillar of the BARF argument, the safety and nutritional adequacy of commercial pet foods. Like all knowledge based on science, our understanding of the nutritional needs of dogs is incomplete and always evolving. However, admitting that we do not know everything is not tantamount to admitting we know nothing. The basic nutrient requirements of our pets are well-established by decades of research, and despite the claims of BARF proponents there is no evidence that nutritional disease are widespread among pets fed balanced commercial diets.
Commercial dog foods are formulated according to AAFCO standards based on extensive nutritional research. These foods are testing through laboratory methods for nutrient content before and after processing, and many are subjected to feeding trials to determine their digestibility and the adequacy of their nutritional content as fed to healthy dogs. These reference standards and limited feeding trials are, like the basic pharmacology and preclinical testing of pharmaceuticals, not perfect, and it is certainly likely that advances in our understanding of dogs’ nutritional needs as well as epidemiologic studies of dogs fed commercial diets will uncover changes that need to be made in the formulations of commercial diets. But the data we do have strongly supports the nutritional appropriateness of these foods. 13,14
By contrast, homemade and commercial raw diets are seldom tested for nutritional adequacy, and when they have been tested they have usually failed to meet known nutrient requirements. 15-18. The knowledge of established nutritional science concerning the adequacy of commercial pet diets, imperfect though it may be, is certainly superior to the near total ignorance of the nutritional adequacy of most homemade of commercial raw diets.
There are many specific criticisms of commercial dog foods made in support of the BARF concept, but there is little evidence to support most of them, and some are clearly false. There are far more than I can deal with in a reasonable space, but I will address a few of the more common of these claims.

  1. Commercial Dog Food Makes Dogs Sick: There is no evidence to support the claim that degenerative and immune-mediated diseases or cancers are caused by commercial pet foods. These conditions are the usual targets of alternative medicine proponents because the gaps in our knowledge about the etiology of these diseases leave room for them to insert their favorite bogeymen, in this case commercial pet food. The likelihood is that the prevalence of these categories of disease reflects, at least to some extent, the aging of the pet population, which is the result of the reduction in historic causes of mortality such as infectious diseases, trauma, and of course malnutrition.
  2. Commercial Dog Foods are Toxic: The insinuation that commercial pet foods are full of “toxins” is also unsupported. Common preservatives, such as ethoxyquin, butylated hydroxytoluene, and others with scary-sounding chemical names, have been in use in human and animal foods for decades and studied extensively, and there is no published evidence to support the many claims and anecdotes that indicate these are responsible for disease.19,20 Synthetic preservatives are more effective than “natural” anti-oxidants, and they are an important tool for reducing food-borne illness.
    Anti-vaccine activists have mercury, aluminum, and anti-freeze, and BARF advocates have preservatives and artificial flavoring and coloring agents. What neither have is solid evidence to support their fear-mongering regarding these substances
  3. Dogs Can’t Digest Grain: It is frequently claimed, based primarily on the fallacious logic of “evolutionary nutrition,” that dogs are incapable of digesting grains or that these make poor nutrient sources in dog foods. Extensive evidence from laboratory research and feeding trials illustrates this is false and that cooked grains are excellent energy sources and can also provide protein and other important nutrients to dogs.21,23 Grains are also often blamed for food allergies, but while some dogs may develop allergies to plant proteins, the evidence suggests that the vast majority of food sensitivities in dogs are to animal proteins.24
  4. Cooking Destroys Nutrients: BARFers like to claim that cooking destroys nutrients, so processed foods must be nutrient deficient. It is true that some nutrients are destroyed by cooking, but the relationship between temperature and cooking time and the final level of these nutrients in the food is well established, and commercial foods are supplemented to account for this and extensively tested in vitro and in vivo to ensure adequate nutrient levels. Other nutrients, particularly carbohydrates, are made more available by cooking.22,23 And cooking destroys many parasites and bacterial organisms responsible for serious foodborne illness.
    Our ancestors ate raw food for millennia prior to the discovery of fire, and our nearest living relatives, chimpanzees, don’t cook their food. Yet for some reason even most advocates of BARF diets for dogs don’t eat primarily raw plants, insects, and the occasional bit of scavenged or deliberately killed raw meat that “evolutionary nutrition” would suggest they should be eating.
  5. Commercial Dog Food is Made from Dead Pets: One of the most repulsive accusations made concerning commercial diets is that manufacturers routinely include the rendered carcasses of euthanized pets in their products. Such a practice would be illegal and has been specifically disavowed by dog food manufacturers and the plants that slaughterhouses and rendering plants that provide them with their ingredients. The FDA has investigated this story and has not found evidence to support it.

It is true that miniscule levels of pentobarbital, an anesthetic used to euthanize animals, have been found in some foods. The source of this has not been identified, though no trace of dog or cat DNA was found in the contaminated food. The most likely source of the contaminant is horses who were euthanized with pentobarbital and improperly rendered along with approved sources of meat for pet foods, though this has not been clearly proven. And it is also true that a few rare cases of dog remains being processed by rendering plants that also supplied pet food manufacturers with ingredients have been documented. However, for this to be a common practice, rather than a rare exception, would require a truly enormous and perfect conspiracy of manufacturers, rendering plants, and government, and as of yet no whistle-blower, journalist, or undercover animal rights activist has yet come forward to reveal evidence of any such conspiracy.

The Bottom Line

The argument that dogs are designed by their evolutionary history to eat raw meat based diets is riddled with errors and fallacies and ignores the impact of tens of thousands of years of domestication and cohabitation with humans on the physiology of our canine friends. The accusations that commercial dog foods are nutritionally inadequate or unsafe are not supported by any objective or scientific evidence, only anecdotes, intuition, and conspiracy theories. There is, in contrast, significant evidence that commercial dog foods are nutritious and healthy and that they have contributed to greater longevity and reduced nutritional and infectious disease morbidity of dogs fed these diets.
The benefits promised by advocates of BARF diets for dogs are numerous. Greater health, less disease, better quality of life, and much more. Dr. Billinghurst’s web site even claims, “Eating bones for a dog is a joyous experience. It is so enjoyed by dogs that it actually of itself boosts their immune system.” However, there is absolutely no scientific evidence to support these claims. BARF proponents have no shortage of opinions and anecdotes to demonstrate the benefits of their diets, but they have a severe shortage of data.

The risks of raw meat based diets, however, are well-documented. Homemade diets and commercial BARF diets are often demonstrable unbalanced and have severe nutritional deficiencies or excesses.16-18 Dogs have been shown to acquire and shed parasitic organisms and potentially lethal infectious diseases associated with raw meat, including pathogenic strains of E. coli and Salmonella.25-27 Many other pathogens have been identified in raw diets or raw meat ingredients, and these represent a risk not only to the dogs fed these diets but to their owners, particularly children and people with compromised immune systems.29-30 The bones often included in such diets can cause fractured teeth and gastrointestinal diseases, including obstructed or perforated intestines, and the FDA recently warned pet owners against feeding bones to their canine companions.

So with a dodgy theory behind it, no sound evidence of benefits, and clear risks, there is no justification for recommending raw meat based diets for dogs. As always, I remain open to the possibility that new evidence may emerge to document benefits from such diets that might justify the risks they present, but for now this feeding approach appears to be simply another form of CAM mythology supported only by anecdote and unsound logic.

References

  1. Pitcairn RH, Pitcairn SH. Dr. Pitcairn’s complete guide to natural health for dogs and cats. 3rd ed. Rodale; 2005.
  2. Vila C, Maldonado JE, Wayne RK. Phylogenetic relationships, evolution, and genetic diversity of the domestic dog. Journal of Heredity 1999;90(1):71-77.
  3. Wayne RK. Molecular evolution of the family dog. Trends in Genetics 1993;9(6);218-224.
  4. Serpell J (editor). The domestic dog: Its evolution, behavior and interactions with people. New York, NY, US: Cambridge University Press; 1995.
  5. Ziesenis A, Wissdorf H. [The ligaments and menisci of the femorotibial joint of the wolf (Canis lupus L., 1758) — anatomic and functional analysis in comparison with the domestic dog (Canis lupus f. familiaris)]. Gegenbaurs Morphol Jahrb 1990;136(6):759-73.
  6. Lauer BH, Kuyt E, Baker BE. Wolf milk. I. Arctic wolf (Canis lupus arctos) and husky milk: gross composition and fatty acid constitution. Canadian Journal of Zoology 1969;47(1):99-102.
  7. Maia OB, Gouveia AM. Birth and mortality of maned wolves Chrysocyon brachyurus in captivity. Brazilian Journal of Biology 2002; 62(1):25-32.
  8. Smith DW, Stahler DR, Albers E, Metz M, Williamson L, et al. Yellowstone Wolf Project: Annual Report, 2008. 2009. National Park Service, Yellowstone Center for Resources, Yellowstone National Park, Wyoming, YCR-2009-03.
  9. Max Planck Institute for Demographic Research. Longevity records; Lifespans of mammals, birds, reptiles, amphibians and fish. Accessed 05/07/2010 at http://www.demogr.mpg.de/longevityrecords/0203.htm
  10. Waddell W. Nutrition. In: Red Wolf Husbandry Manual Guidelines for Captive Management. Red Wolf SSP Management Group American Association of Zoos and Aquariums. 1998.
  11. Newton K. Nutrition. In: Mexican Wolf Husbandry Manual. Mexican Wolf SSP Management Group. American Association of Zoos and Aquariums. 1995.
  12. Allen ME. Maned wolf nutritional management. In: Husbandry Manual for the Maned Wolf Chrysocyon brachyurus. N.B. Fletchall, M. Rodden and S. Taylor, Eds. American Association of Zoos and Aquariums. 1995.
  13. Crane SW, Griffin RW, Messent PR. Introduction to commercial pet foods. In: Hand MS, Thatcher CD, Remillard RL, Roudebush P, editors. Small animal clinical nutrition. 4th ed. Topeka, KS, US: Mark Morris Institute; 2000. p. 111-126.
  14. Cowell CS, Stout NP, Brinkman MF, Moser EA, Crane SW. Making Commercial Pet Foods. In: Hand MS, Thatcher CD, Remillard RL, Roudebush P, editors. Small animal clinical nutrition. 4th ed. Topeka, KS, US: Mark Morris Institute; 2000. p. 127-146.
  15. Freeman L, Michel K. Nutritional analysis of 5 types of “Raw Food Diets.” Journal of the American Veterinary Medical Association. 2001;218(5):705.
  16. Lauten SD, Smith TM, Kirk CA, Bartges JW, Adams A, Wynn SG. Computer Analysis of Nutrient Sufficiency of Published Home-Cooked Diets for Dogs and Cats. Proceedings of the American College of Veterinary Internal Medicine Forum 2005.
  17. Roudebush P, Cowell CS. Results of a hypoallergenic diet survey of veterinarians in North America with a nutritional evaluation of homemade diet prescriptions. Veterinary Dermatology 1992;3:23-28.
  18. 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. Journal of the American Veterinary Medical Association 2009;234(8):1041-8.
  19. Wortinger A. Nutritional myths. Journal of the American Animal Hospital Association 2005;41:276.
  20. Dzanis DA. Safety of ethoxyquin in dog foods. Journal of Nutrition 1991;121:S163-S164.
  21. Walker JA, Harmon DL, Gross KL, Collings GF. Evaluation of nutrient utilization in the canine using ileal cannulation technique. Journal of Nutrition 1994;124(12 Suppl):2672S-2676S.
  22. Trân ðình Quang. Extrusion processing effects on dry canine diets. 2008 Ph.D. Thesis, Wageningen University and Research Centre, Wageningen, the Netherlands.
  23. Gross KL, Wedekind KJ, Cowell CS, Schoenherr WD, Jewell DE, et al. Nutrients. In: Hand MS, Thatcher CD, Remillard RL, Roudebush P, editors. Small animal clinical nutrition. 4th ed. Topeka, KS, US: Mark Morris Institute; 2000. p. 21-107.
  24. Roudebush P, Guilfor WG, Shanley K. Adverse reactions to food. In: Hand MS, Thatcher CD, Remillard RL, Roudebush P, editors. Small animal clinical nutrition. 4th ed. Topeka, KS, US: Mark Morris Institute; 2000. p. 431-453..
  25. Chengapappa, M., et al. Prevalence of Salmonella in raw meat diets used in racing greyhounds. Journal of Veterinary Diagnostic Investigations 1993;5:372-7.
  26. Finley, R. et al. The risk of Salmonella shedding by dogs fed Salmonella-contaminated commercial raw food diets. Canadian Veterinary Journal 2007;8:69-75.
  27. Joffe, D., Schlesinger, D. Preliminary assessment of the risk of Salmonella infection in dogs fed raw chicken diets. Canadian Veterinary Journal 2002;43:441-442.
  28. Weese, J. et al. Bacteriological evaluation of commercial canine and feline raw diets. Canadian Veterinary Journal 2005;46:513–516.
  29. Strohmeyer, R.A., et al., Evaluation of bacterial and protozoal contamination of commercially-available raw meat diets for dogs. Journal of the American Veterinary Medical Association 2006;228:537-542.
  30. LeJeune JT, Hancock DD. Public health concerns associated with feeding raw meat diets to dogs. Journal of the American veterinary Medical Association 2001;219(9);1222-25.
  31. Vila C, Savolainen P, Maldonado JE, Amorim IR, Rice JE, et al. Multiple and ancient origins of the domestic dog. Science 1997;276:1687-9.

ABOUT THE AUTHOR:

Brennen McKenzie, MA, VMD is a 2001 graduate of the University of Pennsylvania School of Veterinary Medicine, and he works as a small animal veterinarian in private practice in California. He has a special interest in promoting science-based veterinary medicine and is currently chair of the Practitioner Committee for the Evidence-Based Veterinary Medical Association. He has published articles on evidence-based medicine in veterinary science journals, and he also writes about both science-based and “alternative” veterinary medicine as the SkeptVet.

Prior to becoming a veterinarian, Dr. McKenzie completed a Master’s Degree in animal behavior, studying captive chimpanzees and working as a specialist in environmental enrichment for captive primates. He reads too much, with a predilection for science fiction, philosophy, linguistics, and of course skepticism. He travels too much and has climbed Mt. Kilimanjaro and run with the bulls in Pamplona. He also plays the Irish pennywhistle and the mandolin and has been known to wear the kilt on occassion, though he does not claim to do any of these well.

Posted in: Nutrition, Veterinary medicine

Leave a Comment (96) ↓

96 thoughts on “Raw Meat and Bone Diets for Dogs: It’s Enough to Make You BARF

  1. wickerman says:

    Thank you, Dr. McKenzie, for such a detailed and thorough break down of all that alt-vet crap that those guys defend. I haven’t met anyone who believes in this kind of woo – maybe it’s more common in Northern America than in Europe.

    I’m a proud owner of 3 dogs now, but never had a dog until 2 years ago. When i was about to have my first dog (a mutt/beagle combo that was going to be abandoned from the warehouse where he lived) i looked up on the internet to try to understand what would be the best food (within reason, i’m not rich) to give to him. I came upon this site:

    http://www.dogfoodanalysis.com/

    (I have no relation with that or any other dog-related website)

    In it, they state that “Grains contain protein too – but it’s far less bioavailable protein for a carnivore that lacks the digestive enzymes needed to digest plants. Protein derived from meat represents a far higher quality and species-appropriate diet for a carnivore than plant proteins ever can be” (at http://www.dogfoodanalysis.com/how-do-you-rate-the-foods.html ) and “Corn is a difficult to digest grain of little nutritional value for canines, and that is commonly associated with allergies and yeast infections” (at, for example, http://www.dogfoodanalysis.com/dog_food_reviews/showproduct.php?product=1158&cat=6 ).

    I don’t pretend to know anything about this – i’m just a guy that wants to give his dogs good food. With that in mind, i looked into the highest rated foods that they scored and tried to find out which ones were available here in Europe (I’m in Portugal). I found a couple of brands that fitted the bill and i’ve even found out that on large (13,5 kg or more) dry food bags, they are actually cheaper than your typical Pedigree Pal or Eukanuba!

    That said, my questions I guess would be:
    a) what ingredients would you say should *not* be present in a dog’s diet, and
    b) If corn (and, to an extent, wheat) are OK for dogs, why would dog-loving people defend the idea that they are not?

    Thank you in advance!
    Pedro

  2. Jann Bellamy says:

    Very interesting post!
    My basset hound is obviously no wolf — he can’t even catch a squirrel and I’m not sure he’d know what to do with it if he did.

  3. Draal says:

    I see a lot of parallels with the debate between infant formula and breast milk and raw diet versus commercial dog food.

    By the way, BARF was featured on an episode of Dirty Jobs. Enjoy!:
    http://dsc.discovery.com/videos/dirty-jobs-vellum.html

  4. tracy_allison_altman says:

    I’m delighted to see this thoughtful review of raw doggie diets. You’ve done an excellent job of providing evidence about a topic I’ve often wondered about. As an enthusiastic dog owner, it’s been difficult to get unbiased evidence.

    I write a blog called Evidence Soup where I like to say I’m opening up a big ol’ can of evidence and then trying to explain it. This weekend I’ll mention your post and provide a link – I know my readers will appreciate the effort you put into recapping the evidence.

  5. jimpurdy says:

    Great article, but you did something that always turns me off when done by self-proclaimed experts, usually MDs in long white coats:

    You repeatedly put down “anecdotal” reports. Why do doctors trust studies paid for by drug companies, but they dismiss adverse effects reported by their own patients as “anecdotal?”

    I have often changed doctors who don’t listen to my medication-related side effects. Do intelligent young medical students somehow become both gullible (believing Big Pharma) and authoritarian (ignoring patients) by the time they finish med school?

    Jim Purdy
    The 50 Best Health Blogs

  6. Scott says:

    You repeatedly put down “anecdotal” reports. Why do doctors trust studies paid for by drug companies, but they dismiss adverse effects reported by their own patients as “anecdotal?”

    There are quite a few reasons:

    – a single report cannot distinguish between coincidence and a real effect
    – anecdotes are inherently biased because the unremarkable cases don’t get mentioned
    – they’re inherently uncontrolled and imprecisely measured
    – many others

    A good scientist does not completely disregard anecdote, but they are useful ONLY for hypothesis generation. They cannot provide good evidence to support or falsify a hypothesis. And in particular, when anecdotes contradict the findings of much higher-quality evidence, the higher-quality evidence wins.

    That said, a patient report of symptoms is not an anecdote in the context of the treatment of that patient, and certainly should not be ignored. However, a patient’s self-diagnosis (which is what you really seem to mean) may be properly disregarded if it is insufficiently supported and contradictory to the known evidence.

  7. Thanks you for an excellent article Dr. McKenzie.

    A few years ago I was looking into different diet options for my German Shepard. She was having allergy issues and problems with diarrhea which could be related. I looked into the BARF diet at that point but decided that it would be more expensive (not less like proponents claim) and be too time consuming.

    Instead I just settled with the dog food that she seemed to do best with, but I always had a little pang of guilt in the back of my mind that I wasn’t doing all I could be for her. This article along with a recent bit on the Dr Dean Edell show has removed my guilt and made me realize that a reliable commercial food is the best option for her.

    To jimpurdy:

    You obviously are new to SBM or you would be familiar with the phrase “the plural of anecdote is not data” or some derivation.

    Anecdotes are important yes, as a starting point for investigation, but they cannot be used as evidence. For instance a doctor notices a certain trend in his patients and uses the experience to design a study.

    Do some research into the fallibility of the human memory, selection and confirmation bias, and the placebo effect to understand why. Even the best doctors and scientists aren’t exempt.

  8. aeauooo says:

    How am I supposed to feed my dog (if I actually owned one)?

    Just outside of the walled city of Harar, Ethiopia lives a congenial gentleman known as the “Hyena Man,” who spends at least part of his day collecting bones, hide, and offal from the butchers in that city. After sunset, he feeds the hyenas that gather outside of his home (One of the most impressive sounds I have ever heard was that made by a hyena crushing the skull of a goat in its jaws).

    The Hyena Man serves a social function by keeping the hyenas outside of the walls of Harar, but he also appears to make a tidy profit from the tourists who come to watch him feed the hyenas.

    As admirable of a profession as the Hyena Man has, I would rather not spend time collecting buckets of BARF.

  9. DVMKurmes says:

    @jimpurdy;
    I think your concern is a bit of a straw man. We don’t put much value in anecdotes as evidence that a treatment, or a feeding method, is superior, because there are too many ways we can fool ourselves (how many people are convinced homeopathy works?). Placing a low value on anecdotal evidence in general is not the same thing as listening to an individual patient’s concerns. Side effects do happen, just as certain animals may have food allergies or other problems that might make one diet inappropriate for an individual. I don’t think Dr. Mackenzie or anyone else here on this blog would scoff at an individual’s concern about something. Even if the concern is unfounded, it is real to that individual, and should be dealt with compassionately.

  10. vannin says:

    Very helpful and thorough. Thank-you.

  11. All dog foods meet a minimum nutritional standard. So what’s the difference between the cheapest grocery store dog foods that leave dogs with a dry coats, and the more expensive foods that sleek and glossy dogs eat?

  12. Kultakutri says:

    @Alison
    Cheap vs. expensive pet food – well, my experience of a former crazy cat lady says this: feed a bunch of cats by that colourful cheap kibble and although they may not fail to thrive, your place will stink to high heaven because the cats will be bloated and fart. Also, I suspect that the cats need a certain amount of animal protein because they simply ate more of that cheap stuff. This is also what other cat people tell me so there may be a point.
    I had calculated that if I feed a decent food with high animal protein content, the cats eat less, there’s less litterbox cleaning and very importantly, my place is not a gas chamber, for approximately the same price for daily dose.

    Nowadays, my only cat is fed a hellishly expensive veterinary diet because she has pancreas insufficiency. If that processed kibble is ebil and what else, then… well, within two weeks, a sick apathetic animal changed into that good old evil feline. Anecdotal but fair enough for me.

  13. Thanks for this Dr. McKenzie. I have a little 12 year old IG that is troublesome to feed. She just doesn’t have much appetite. Our vet has check her out and she is fine, but I was having a hard time finding food that she would eat.

    A young salespeople at our local pet supply store was trying to sell me on a raw food diet, but I explained to him that I have small children and did not want raw meat out where they could handle or possible eat it (I don’t think they would, but sometimes who knows with kids). I worked in a few restaurants, so I had been taught that one should use certain precautions with raw meat.

    It was a bit disconcerting that the young man assured me that any microbes in the food could be handled by a dog’s digestive track, but he seemed completely unaware of that children do not have similar protection.

    Buyer beware, I guess. We did find a food that our IG will eat, fresh cooked dog food, and also found that more exercise keeps her appetite up.

  14. Sorry, for the non-sighthound enthusiastic. IG = Italian Greyhound or knee high greyhound.

  15. Grumpy Grampy says:

    I’ll give my anecdotal account following your long winded anecdotal recitation. About 10 years ago my two daschunds were getting fat regardless of what commercial dog food I fed them. I investigated the BARF feeding and found it plausible. In a month or two my dogs and I figured out how they wanted to be fed. They also got a vitamin supplement. They lost weight, their coats became shiny, and their stools were no longer sloppy. They were healthy dogs with very few visits to the vet. My boy died last year after a long bout with cushing’s disease, I’m sure you could find a way to attribute that to his diet. My girl is 14 ½ years old which recently surprised my vet. All anecdotal, but if we were hit by an asteroid and I starved to death Scooter would gladly feast on my corpse and muse, “Thanks for DinDin Dad…” and your Fido would do the same.

  16. jwmiller says:

    I too am familiar with the web site http://www.dogfoodanalysis.com/ and would like to know the answers to the question Pedro asked

    “That said, my questions I guess would be:
    a) what ingredients would you say should *not* be present in a dog’s diet, and
    b) If corn (and, to an extent, wheat) are OK for dogs, why would dog-loving people defend the idea that they are not?
    Thank you in advance!
    Pedro”

  17. Josie says:

    I read the post with great interest as I am lucky enough to be the caretaker of an *obligate* carnivore, my Bengal cat.

    When I picked her up from the breeder last year I signed a contract stipulating that her primary diet would be raw ground chicken duck or rabbit meat that includes bones.

    For those who are unfamiliar with the breed, Bengals are a cross between a domestic cat and an Asian Wildcat, http://en.wikipedia.org/wiki/Leopard_Cat, my particular kitty is 7 generations removed from her wild ancestor.

    From what the breeder told me and from my own research at Google U I am confident in providing my cat with ground chicken thighs trimmed of fat and ground with a 1200 watt meat grinder to a smoothness somewhere between burger and pate. I also provide her with a high protein dry kibble (that my 16yo muttcat also scarfs up) and a powdered vitamin supplement (also stipulated in the contract).

    Do you have an opinion on cat diets as well as dog diets? I realize the case for Bengals might be different as they are only half descended from kitties that have been human companions for thousands of years.

    @Alison Cummins –In a different context I am pretty sure Taco Bell meets a minimum nutritional standard…but I never feel as good after eating there as I do after a meal at my favorite, more expensive, Italian restaurant.

  18. Scott says:

    Interestingly, our Meezers are entirely uninterested in raw meat. COOKED meat, on the other hand… Well, let’s just say that cooking can be an adventure.

  19. >a) what ingredients would you say should *not* be present in >a dog’s diet, and

    Most of the things that shouldn’t be in dog foods aren’t. Obviously, tissue from dogs represents a potential disease risk, but there is little evidence this is a common ingredient. There are already rules against the use of very low nutrient ingredients such as hair, hoofs, and so on, and no good evidence these are commonly included.

    Again, ingredients are a poor guide to nutrient content and subject to all kinds of irrational subjective responses by humans that may not be relevant.

    Also, I think there are legitimate concerns about ingredients from China and other countries with weaker government monitoring of ingredients, as I think the melamine incident illustrates. I would like to see more transparency about ingredient sources and companies using suppliers from countries with standards equivalent to or better than those in the U.S.

    >b) If corn (and, to an extent, wheat) are OK for dogs, why >would dog-loving people defend the idea that they are not?

    There is currently quite a fad against grains as food ingredients for dogs, especially corn. I’m not sure exactly where it comes from. Some spillover from recent controversies in human nutrition, in particular Michael Pollan’s books, may be involved. While I agree with a lot of what he says, Mr. Pollan does strike a bit of an anti-science note in his most recent book, and he does draw a lot of attention in Omnivore’s Dillemma to the more nepharious behavior of agribusiness and the ubiquitousness of corn-related ingredients in processed foods. This may have bleed over into a more general “corn is bad” notion.

  20. Robin says:

    Captive wolves live longest and are healthiest when fed — guess what? — commercial dog food!

    You made my day! That is a gem I will keep with me for the next time a doggy raw foodie lectures me at the dog park.

    One of my first introductions to SBM was watching a veterinarian chew out a well-meaning but ill informed woman try to treat her cat’s renal failure with herbs and supplements.

    I would love to read more veterinary articles!

    (Pround owner of a 14 year old 85 pound mixed breed. He has no chronic illnesses except arthritis, and he eats kibbles, canned food, and sometimes my leftovers.)

  21. Galadriel says:

    There are already rules against the use of very low nutrient ingredients such as hair, hoofs, and so on, and no good evidence these are commonly included.

    What are “animal by-products” or “meat by-products”? I had guessed it was things like that, or maybe just things like chicken heads. Web searches on something like this don’t exactly turn up answers I’d consider reliable.

    I’d also be very interested in a similar commentary on cat food, since I keep reading that cats are more obligate carnivore than dogs are.

  22. >Do you have an opinion on cat diets as well as dog diets?

    Cats certainly are obligate carnivores, and their nutritional needs reflect this. They require higher protein levels, and they have different and stricter amino acid requirements than dogs. There is some evidence that low-carbohydrate diets have benefits for cats (in the treatment of diabetes mellitus, for example), but there is also research that suggests total calorie intake and body condition are more important than the carbohydrate content of the diet, so the jury is still out on high-protein, high-fat diets.

    And again, we must be careful not to assume ingredients=nutrients. There are diets for cats out there which aggresively market themselves as “grain free” but which are still high carbohydrate diets, they just use potato starches instead of grain starches.

    In any case, it is still not true that grain ingredients are necessarily harmful or useless in cat foods. Grains when processed as they are for pet foods are still highly digestible in cats and can be an appropriate component to cat diets. A balanced, nutritionally appropriate diet can be made with or without grain ingredients, so the specific ingredient source is only a small part of the overall picture.

    Raw diets have most of the same problems in cats as in dogs despite the appeal of the naturalistic fallacy, that ince whole prey arguably is the natural diet for cats (unlike dogs) it must be the optimal diet.

    Cats can shed Salmonella and other pathogens and parasites acquired from raw meat, which is a risk to people and animals in the household. And there are reports of cats dying from infections acquired from raw meat.(Stiver, S. et al. Septicemic salmonellosis in two cats fed a raw meat diet. J AM Anim Hosp Assoc 2003;39:538-42.) And many raw diets for cats turn out, when evaluated carefully, to be nutritionally inappropriate, with either deficiencies or excesses of particular nutrients.

    Cats may do fine with all or partially raw diets, but again there is zero evidence they do better with these than commercial diets, and there is some small evidence of risk from the diets, so at this point there is no strong reason to prefer them. I don’t encourage clients already using such diets to stop doing so, but I do inform them of the risks, emphasize the importance of careful handling of raw ingredients to minimize their own health risks, and I encourage anyone making any kind of homemade diet to consult a veterinary nutritionist to make sure it is nutritionally appropriate.

  23. AAFCO, which produces the standards the federal government and most states adhere to in regulating pet foods, has definitions for “meat,” “meat meal,” and “meat by-products.” These include parts of the animals we generally don’t regard as “food” in the U.S., but remember that this is 1) a cultural opinion, as some such parrts are regularly eaten in other places and 2) not really reliable as a guide to what is healthy for our pets.

    Meat-“Clean flesh derived from slaughtered mammals and is limited to the part of the striate muscle which is skeletal or that which is found in the tongue, in the diaphragm, in the heart, or in the esophagus; with or without the accompanying and overlying fat and the portions of the skin, sinew, nerve and blood vessels which normally accompany the flesh.”
    “The ingredients “meat” or “meat by-products” shall be
    qualified to designate the animal from which the meat or meat
    by-products are derived unless the meat or meat by-products
    are derived from cattle, swine, sheep, goats, or any
    combination thereof. For example, ingredients derived from
    horses shall be listed as “horsemeat” or “horse meat byproducts”.

    Meat Meal-“The rendered product from mammal tissues, exclusive of any added blood, hair, hoof, horn, hide trimmings, manure, stomach and rumen contents except in amounts as many occur unavoidably in good processing practices. It shall not contain added extraneous materials not provided by this definition.”

    Meat By-Product-“The non-rendered, clean parts, other than meat derived from slaughtered mammals. It includes, but is not limited to, lungs, spleen, kidneys, brain, liver, blood, bone, partially defatted low temperature fatty tissue and stomachs and intestines freed from their contents. It does not include hair, horns, teeth and hoofs.”

  24. Still, you haven’t answered the question: if all commercial kibble meets nutritional requirements, why do animals eating some kibbles appear less healthy than others?

    I am totally with the Taco Bell vs Italian parterre comparison. Taco Bell might give you enough calories, protein and liquid water, and if you take a vitamin pill you won’t die of vitamin deficiency diseases, but most of us (including dieticians) think that food can be better than that. Dietary recommendations are to eat lots of fresh fruits and vegetables, for instance, but I can meet my vitamin A and C requirements without them.

    Is it odd that people who know that eating lots of fresh fruit and vegetables is better for them than eating TVP, meat by-products and vitamin pills extrapolate that fresh food is also better for their dogs than TVP, meat by-products and vitamin pills?

    What’s wrong with this extrapolation, and how do you address it?

  25. Angora Rabbit says:

    Dr. McKenzie, thank you for an excellent post and one of the best disclaimers of the “natural” pet food diet that I’ve read in some years. As a nutrition professional who also does animal rescue, this is a topic that adopters regularly barrage me with. Thanks for an excellent link that will inform.

    One of the biggest problems I see in adopters is mistaken belief in the equation Food = Love. As you say, there are a great many obesity-related chronic diseases in pets that could be resolved or reduced with restricted feeding and more exercise.

    I also see the adopters who are gung-ho for a “natural” or “whole food” diet for their pet, and yet can’t manage to feed themselves properly. Alas critters can’t open the refrigerator or vitamin/mineral jar or prepare their own meals. They must rely on us to feed them properly. Complicating this is that geographic regions vary in dietary mineral content; for example, veggies grown in my area are selenium poor. So even eating locally poses concerns. Commercial foods from reputable vendors are an excellent way to assure adequate nutrition, even if used as a “supplement” to other foods.

    Again, very nice post!

  26. Happy Camper says:

    FIY

    Here is a link to one of the most disturbing posts I have ever read about pet nutrition.

    http://www.huffingtonpost.com/2009/03/25/vegan-pet-food-is-it-ok-t_n_178880.html?page=7&show_comment_id=22419808#comment_22419808

  27. Just as an extremely tangential aside- Taco Bell’s* “Fresco” Menu is really quite tasty (cilantro-y), items are lower in calories and fat with more veggies, less cheese. I’ve actually found it to be a pretty good choice compared to other fast food. I love Italian food, but I’m pretty sure that the typical Italian restaurant entree in the U.S. far exceeds the recommended calories for any meal. Not that there’s anything wrong with that, occasionally.

    *I don’t work for, own or have stocks in Taco Bell, but I do like the fresco items and hope if other people do too they’ll keep it on the menu. :)

  28. Galadriel says:

    Thanks for the by-products breakdown. Next question!

    As I (think I) understand it, commercial pet/livestock food is nutritionally complete when fed at the levels suggested on the bag. I’ve never had a pet who needed as much as the bag suggests, and they’d be deathly obese if I gave them that much. Do I need to worry that they’re not getting enough of any particular nutrients if they eat, say, half what the bag suggests for their body weight?

    I can see thinking that designing your own pet meals is more effective, when the pets get everything you put into it, as compared to less than what they “ought” to be getting from commercial food. Me, I just wonder if I ought to be giving them a multivitamin or something.

  29. micheleinmichgan on restaurant choices:
    “Taco Bell’s* “Fresco” Menu is really quite tasty (cilantro-y), items are lower in calories and fat with more veggies, less cheese. I’ve actually found it to be a pretty good choice compared to other fast food. I love Italian food, but I’m pretty sure that the typical Italian restaurant entree in the U.S. far exceeds the recommended calories for any meal.”

    … which is why I said Italian parterre! Um, by which I meant of course, terroir. Oops.

  30. I want to be clear that “nutritionally complete” doesn’t mean “nutritionally perfect for every individual.” It simply means that the food is unlikely to induce gross nutritional deficiency or excess-related disease.

    There is no research to support claims of differences between the health of dogs eating one brand of food or another, and no evidence as of now that homemade diets are as healthy or healthier than commercial diets. This doesn’t mean that these claims aren’t true, only that they are based only on opinion and anecdote, which are notoriously unreliable guides to reality.

    There are very likely differences between foods which are clinically relevant. There are many prescription veterinary diets, for example, with specific nutrient profiles designed to be useful to patients with particular medical issues, and for some of these there is good research evidence the differences are meaningful. It is quite likely that some foods will be better for some individual dogs than others.

    The problem is that without a solid evidentiary basis to guide us, we must rely on lesser quality evidence to make feeding decisions, and this will inevitably lead to erroneous beliefs and conclusions. The best we can do is to head the evidence we do have, bear basic and well-established nutrional science in mind, and not get too vehemently attached to our personal beliefs.

  31. Galadriel,

    The nutrient content of most diets are designed to be relative to calorie content. In other words, if a dog is eating an amount that maintains an optimal body condition, the diet should be appropriate in terms of vitamins, minerals, and other nutrients. The problem, of course, is that most of our pets are obese and grossly overfed, so these may experience some excesses. Foods marketed for weight loss are intended to be suplemmented with micronutrients so that they can be fed at below maintenance calorie levels without inducing deficiencies, as might happen if a maintenance diet was fed at below maintenance levels.

    As for vitamin supplements, there is virtually no research on the subject of general supplementation of healthy pets. Given the state of the evidence concerning such supplementation for humans, which does not suggest a major benefit and does indicate there are some risks, I am not personally convinced it’s a useful thing to do, but I can’t offer a truly science-based opinion.

  32. norrisL says:

    Brennen

    I wish to thank you for an excellent and very thorough article.

    As a veterinarian myself, I am quite aware of the rubbish put forward by people like Lonsdale and Billinghurst. I have also previously heard of the story of euthanased dogs and cats going into pet food and, like yourself, find the suggestion that veterinarians would be associated with such a practice repulsive and so blatantly ridiculous as to show the authors and perpetuators of this lie to be ridiculous.

    I frequently have to re-educate my clients when they come in having been feeding their pets all sorts of bones such as brisket bones, chicken necks (which for some reason seem to be the flavour of the month here in Australia), lamb shanks and many more. Only recently we had a dog die as a result of being fed a diet consisting primarily of raw lamb necks. While the lamb meat itself is often a cause of GI disturbances such as gastroenteritis, pancreatitis or cholangiohepatitis due to the effect of the such a rich, fatty food on the dog’s gut, in this case it was the small intestinal perforation leading to an insidious onset of peritonitis that led to the dog’s demise.

    In our practice we frequently perform dental surgery. It s not unusual that the reason for this is due to the dog being given bones such as a lamb shank, which, with its triangular cross section at the proximal end is a great shape of bone to fracture a tooth. And, if a dog is to fracture a tooth while chewing a bone, which tooth will it be? The first pre-molar? (A tiny, almost insignificant tooth) No, it will be the maxillary fourth premolar or mandibular first molar. Why? Because these are the major chewing teeth and therefore they are the teeth that will fracture when the dog chews inappropriate items such as rocks that some dogs seem to feel are good to chew on, some of the very dangerous toys found in pet shops, and various bones that are often given to dogs.

    Let’s not forget the brisket bones that people seem to feel are great for their dogs’ teeth. These soft bones are great for getting into the narrow spaces between teeth and becoming food for anaerobic bacteria and generating and perpetuating periodontal disease. Periodontal disease is not only an oral issue. The bacteria involved enter the dog’s blood stream and are a contributor to disease throughout the body. Note that it is not at all unusual for me to remove multiple teeth from dogs with severe periodontal disease. The owner’s first concern is “How will he eat?” The answer being, “Better” The bacteria, pus and pain are gone now. But often these same people will return a week or two later and tell me how much the dog’s overall health has improved.

    But the biggest danger of brisket bones is constipation. Actually, obstipation. Constipation so severe, that the affected dog will never pass the rock hard faeces unaided. These dogs WILL die without veterinary treatment. I have spent many a joyful hour removing this concrete like faeces from the colon of anaesthetised dogs.

    Not all commercial dry foods are created equal. There are plenty of commercial dry foods on the market here in Australia that are garbage, are labelled as “balanced diet for dogs” but are nothing like a balance diet.

    My own dogs have been fed exclusively on a well known, premium quality brand of dry dog food for many years. They are given a strictly measured amount of food once a day. They obviously have fresh water available at all times. They are given freeze dried lamb liver as a treat for good behaviour, a training aid. Yes, I know I mentioned the perils of feeding lamb, but a tiny piece of freeze dried lamb liver is a very different thing from a piece of lamb roast.

    By following this regime, my dogs have always been in excellent health. My patients who follow the same regime of feeding are far less likely to spend time in my consultation room than dogs feed inferior quality commercial foods or home made foods.

    In addition to producing excellent foods for use as a maintenance diet for “normal, healthy dogs, the various premium quality food producers also produce a wide range of excellent and life saving prescription foods targeted at a range of diseases in both dogs and cats.

    I note that Dick Pitcairn is, like most followers of homeopathy etc, able to detect forces that people like genuine nutritional scientists of the sbm type cannot, such as that vital ingredient in whole, uncooked diets, “life energy” Good one, Dick! I wonder if Dick also eats a whole, uncooked diet.

    When discussing infectious diseases associated with raw meat, the obvious bacterial food poisonings come to mind. But let’s not forget the delightful Toxoplasma and Neospora which affect cats (Toxo) and dogs (Neospora). These wonderful little bugs infect muscle and nerve tissue and, having seen the effects of both, are an awful and preventable way to die. Don’t feed raw meat.

    The point re average lifespan of wild wolves versus captive wolves holds true for a vast array of mammals. The captives live longer for a whole range of reasons, including, as can easily be demonstrated, diet.

    For example, domestic cats can reasonably expect to have a good chance of living 14 or so years. We often see them living 16, 18 or 20 years. Very occasionally well into their 20′s. In the wild it can be demonstrated through bone density scanning of a large number of “recently deceased” feral cats that the oldest cats were 5-6 years of age. Obviously there are numerous reasons for this life span differential, but diet is certainly one of those reasons.

  33. rmgw says:

    Very many thanks for such an excellent exposition: the BARF diets are widely touted on many “animal-lovers” (as opposed to vegan!) forums and people react fiercely – and illogically – to being told these diets are unecessary.

    To the correspondent with the Huffington Post query: the vegan point of view is that carnivorous “pets” should not be prioritised over “food” species: dogs can be vegan and cats are a problem.

  34. Alison – parterre? you lost me. Wikipedia says parterre is a form of garden construction, Italian Garden Construction? And I prefer my taco and ravioli sans terrier, please. :)

    Although, Monty the hound loves pasta, when she can steal it.

  35. Oh wait, terroir, not terrier. Wikipedia says this is the idea that tea, wine or coffee gets it’s flavor from local characteristics such as geography, soil, climate, etc.

    I guess you mean something like food with local ingredients? I think in the states they call this slow food. Or I could be way off, since I started with the terrier reference.

    Just goes to show, you don’t have to be smart to enjoy science. :)

  36. Brennen McKenzie on food and nutrients:
    “I want to be clear that “nutritionally complete” doesn’t mean “nutritionally perfect for every individual.” It simply means that the food is unlikely to induce gross nutritional deficiency or excess-related disease.”

    Exactly. Just like I could live on TVP, powdered meat by-product and a vitamin pill. It would be unlikely to induce gross nutritional deficiency. And there are in fact various people with medical conditions who live exclusively on parenteral feeding withoug gross nutritional deficiency. That is, they don’t die of scurvy, beriberi or kwashiorkor, just as I wouldn’t on my proposed diet and just as my dog doesn’t when she eats kibble (which is basically that proposed diet). (Of course she wouldn’t die of scurvy anyway, no matter what was in her food.)

    However, humans are still urged to eat fresh food. Because eating fresh food is better all-round. Even though we get salmonellosis when we cook our own chicken and cook with eggs; even though we get hamburger disease from ground meat; even though we get e-coli poisoning from fresh spinach — our various national dietetics associations still want us eating fresh or home-prepared food.

    And then we turn around and feed our dogs kibble, which is the opposite of what is supposed to be best for us. I don’t think it’s insane to wonder whether, if dieticians prefer us to eat “real food” instead of kibble, whether our dogs would be better off eating “real food” instead of kibble too.

    Look, I feed my dogs kibble. It’s convienient and easy to measure. They have nice dry poops that are easy to pick up. I buy special, expensive, teeth-cleaning formulations alternated with a specially-ordered expensive liver disease formulations for my old dog and a lamb formulation for my young dog. (Lamb because I fancifully imagine sheep to live somewhat less miserable lives than many other livestock.)

    I don’t feed them my leftovers because they might have onion in them and because a dog who knows it’s getting your leftovers is a total pain in the butt at mealtime.

    The internets explain that you can make the tradeoff between the risk of intestinal perforation from eating bones and the risk of peridontal disease from not eating bones by feeding your dog whole animals. That way the fur and feathers insulate the bones in the gut. I’ve never investigated this theory further because I don’t have whole animals to feed my dogs so I don’t have to think about it. (Though I know someone who raises rabbits to feed her dogs, which could make sense for me when I lose my job and money isn’t good any more because rabbits can be raised on various cheap things findable in a city. I’m not there yet and I’m not sure I ever will be.)

    But still, every time I feed my dogs kibble I think that I am not supposed to eat kibble, I am supposed to eat “real food.” And I wonder if I could be doing better by my dogs.

    I also wonder if I could decouple from industry just that little bit more. It’s nice to be self-reliant. If I don’t need Kraft to formulate a complete meal for me, why should I need Ralston-Purina to formulate a complete meal for my dog? Why not take back some do-it-my-selfness?

    There are pragmatic reasons I feed my dogs kibble, but thinking there should be better options is not insane.

  37. Galadriel says:

    Hmm, Dr. McKenzie, I think you only tangentially addressed my question. You say that obese dogs may be getting excesses; you say that weight loss formulations can be fed at lower-than-maintenance amounts. But how does that apply? I’m talking about dogs that are AT a good weight and should stay there; these are dogs who need an adult maintenance amount, and the amount they need to stay at a good weight is significantly less than the bag recommends.

    Sure, a commercial diet is *supposed* to be calorie appropriate for the dog at the amount they suggest, and then they get their full nutritional amount.

    But I have not *ever* had a dog in my care who needed the suggested maintenance amount on any dog food bag, and I’ve had a *lot* of dogs go through my hands for a single person (I used to foster for dog rescue). Weight gain, sure; sometimes they arrived skiiiinny. But not maintenance. I currently have three seniors, and our vets are really happy with how their weight has been for years, and to stay at this weight they each eat not-quite-half what the (senior kibble) dog food bag recommends for their weights. If I fed them what the bag suggests for maintenance, they *would* be obese.

    I tell you what, from my limited perspective, I think I may have a good guess as to part of the reason why there are so many obese dogs.

    So it seems to me that the dog food companies are scaling the suggested caloric intake badly–since I’ve never had a dog who needed anything like the “maintenance” amount suggestions–and so I am concerned that my dogs (and others) are not really getting everything they need. I don’t know what they do need, of course, not being a canine nutritionist. I don’t know if it might indeed be adequate nutrition at this level. They seem okay, and their yearly bloodwork comes back mostly fine (all things considered); maybe it’s not a problem. How would I judge? Maybe they need more of some nutrient in particular, or of all of them, or…? What does one do to even try to make up whatever may be lacking?

  38. BillyJoe says:

    Scott,

    “A good scientist does not completely disregard anecdote, but they are useful ONLY for hypothesis generation. They cannot provide good evidence to support or falsify a hypothesis.”

    That is not entirely correct.
    A very powerful anecdote can overcome that reticence.

    After seeing some patients with RIF pain die, I guess the first surgeon who operated on such a patient, found an inflammed appendix, and removed it, would not do a controlled clinical trial before he trusted his anecdote to try this on all his subsequent patients with RIF pain.

    (Of course, failing to find an inflammed appendix in some of these patients, probably led to stricter selection criteria over time)

  39. Alison – I’m no expert but a few ruminations. If you believe the nature shows, primates seem to rely on fresh fruits and vegetables more than canines. If you think that a chimp or great ape is unlikely to pass up palatable fruits or vegetables in the wild, while a wild dog or wolf may rely on hunting (not grassing the typical berries, clovers, etc that another omnivore might eat) and the the main vegetables that they do get may be partly digested by the prey, then I would not find it surprising that canine may need far less fresh fruits and vegetables than primates (us).

    As to processed vs unprocessed foods – My understanding is that the primary concern with processed foods for humans is the things added to either preserve the food or make it more palatable/marketable, preservatives, salt, sugar, coloring. I think we could make a human ration that would be nutritionally appropriate, aside from the need that humans have for some occasional fresh vegtables or fruits. (which may not be needed by canines.) It’s just not very marketable.

    As to self-sufficiency. Having been raised by parents that were children’ during the depression, I would say a dog that needs their human to raise bunnies for them, is not well adapted to a self-sufficient situation. In a self-sufficient situation, dogs help hunt, herd, or kill vermin and they live as long as they live, the optimal health of a dog is a lower priority when most of your day is spent making sure you or your family has food or shelter.

  40. rosemary says:

    http://www.nytimes.com/2010/06/01/health/01brod.html
    If you scroll down, you will see, “’All pet foods are made from the byproducts of human food production,’ Dr. Nestle explained. ‘No matter what the package says, your dog is not getting whole chicken breasts, but what remains after the breasts have been removed for human food.’”

    Jimpurdy, why do doctors “dismiss adverse effects reported by their own patients as ‘anecdotal’?” They don’t if they are plausible. If they are plausible, rather than the kind about a patient taking a drug and seeing white silvers come out of his skin – one reported to me – they investigate. If they find what appears to be a side effect, they may even report it to the FDA and write it up as a case report for a medical journal. When many similar reports are received, the FDA investigates. So do scientists reading the case reports.

    Grumpy Grampy, my anecdotal account would lead to a different conclusion than yours if in fact anecdotes alone demonstrated cause and effect. My 2 Borzoi, Russian Wolfhounds, are free fed Beneful, a Purina commercial kibble sold in the supermarket. I refill the bowls when they empty them. I also give them a little bit of meat most days as a treat. The meat is purchased from the supermarket deli counter since I myself do not eat meat. And I give them marrow bones a couple of times a week which I know is not recommended, but they like them and I’ve had dogs all my life and have always done that. However, they often leave marrow in them. My dogs are quite healthy and thin and they do not beg. The bitch is almost 10. The dog almost 3. The dog is exceedingly tall even for a Borzoi – at least 36 inches to his shoulder. His back is above my waist. His chin is above the kitchen counter, but he only weighs 86 pounds.

    My six cats are all very healthy which is amazing because they seem quite old. I don’t know their ages because I got them all when they were old, too old for the humane society to take. I’ve always been an animal lover. I have a friend who owns a large boarding kennel. I help him out and he cares for my animals if I go away. Most of my cats came from his cattery. People left them. That doesn’t happen often with dogs. We can usually place dogs in good homes, but not cats. My cats get a commercial brand of kibble. One who doesn’t like litter boxes goes out to the bathroom like a dog and supplements her diet with fresh kill. Two of my cats are obese, but since I have so many I can’t control that. However, that doesn’t seem to have effected their longevity.

  41. TsuDhoNimh says:

    #Josie – At F7 (7 generations removed from the original cross with the wild ancestor) you no longer have a ‘wild’ cat. You have a pretty spotted moggy, and the genetic contribution of the Felis bengalensis is mostly the spotted pattern.

    My neighbor’s two Bengals (F4) are thriving on commercial kibble.

    I am the “owner” of two cats with strong strains of wild cat. One Savannah (African Serval descent of unknown generation status, estimated to be F4). The other, a mutt cat, is F4 F. bengalensis and F3 F. Chaus and therefore not eligible for either breed registry. They are happy crunching commercial kibble. They are sleek, active and radiating healthy qi from every meridian.

    My mutt cross voluntarily abandoned her ground raw chicken diet (mixed by her breeder) and in a couple of days she was walking past it to get to the kibble.

    ground chicken thighs trimmed of fat and ground to a smoothness somewhere between burger and pate … high protein dry kibble … and a powdered vitamin supplement (also stipulated in the contract).

    Commercial kibble has the supplements, mixed at the right quantities for the species.

    ***************
    @Brennan … includes, but is not limited to, lungs, spleen, kidneys, brain, liver, (snip) and stomachs and intestines freed from their contents
    That’s what wild cats, and my outdoor cats, devour first … the heads and the guts … followed by breast and legs. So avoiding things with meat byproducts you are going against the “natural” feeding pattern.

    ‘Splain me that, BARF proponents: why are you feeding steak and bones and not the liver and lights.

    ****************
    @Alison “if all commercial kibble meets nutritional requirements, why do animals eating some kibbles appear less healthy than others?
    In my experience, the cats or dogs eating nothing BUT commercial foods look healthier than those that snack on kibble between cadging snacks of human food from their owners. Before you blame the kibble, check the rest of the diet.

    I have fed cats on generic kibble for years (supermarket brand) and they looked sleek and sassy.

    House-mate’s dogs had 99.44% commercial dry food – fed ad-lib – and a very few snacks of meat trimmings … they lived to be 12 and 14 years respectively, which for large-breed dogs is a long life.

    *************
    Michele I think we could make a human ration that would be nutritionally appropriate MREs?

  42. wickerman says:

    @Rosemary, regarding the NYT article – that’s not what the makers of the food i buy for my dogs imply:

    http://www.orijen.ca

    I found their food trustworthy and my dogs love it. I have no conflict of interest here – i’m just a costumer (and not even a Canadian one!).

  43. rosemary says:

    wickerman, have you investigated to determine who is correct? If you don’t have the time and have to decide between them, will you choose the manufacturer over the scientists regarding both what goes into the specific product and the benefits offered?

    Without investigating, I would suspect that there may be an exception the scientists quoted missed – a company that really is using whole foods to start. But it would take an awful lot of solid, consistently reproducible scientific evidence to convince me that the scientists are wrong about benefits and the manufacturers are correct.

    Dogs love cat excrement. That doesn’t mean that it is either good or bad for them. All it means is that they love it. And because your dogs do well on one brand doesn’t mean that they wouldn’t do just as well on another, a much cheaper one.

    Regarding raw cat food, I read in a trade publication that it hasn’t taken off very well because cats “are finicky eaters” and refuse to eat it. I’ve also read promotional material from the organic, natural, holistic, alt, supplement pushing animal quacks telling customers to refrain from giving cats anything else to eat other than their products in order to force them to eat the “raw, organic, natural” outrageously expensive stuff that they sell. I think that is cruel.

  44. rosemary says:

    Wickerman, have I missed something? Your second comment seems to contradict your first.

    First, “Thank you, Dr. McKenzie, for such a detailed and thorough break down of all that alt-vet crap that those guys defend. I haven’t met anyone who believes in this kind of woo – maybe it’s more common in Northern America than in Europe…i looked into the highest rated foods that they scored and tried to find out which ones were available here in Europe (I’m in Portugal). I found a couple of brands that fitted the bill and i’ve even found out that on large (13,5 kg or more) dry food bags, they are actually cheaper than your typical Pedigree Pal or Eukanuba!”

    Second, “@Rosemary, regarding the NYT article – that’s not what the makers of the food i buy for my dogs imply:
    http://www.orijen.ca
    I found their food trustworthy and my dogs love it. ”

    When I looked at your “trustworthy” food manufacturer’s site, it sounded like “alt-vet crap” to me. I didn’t look for prices but would suspect it would be very expensive “alt-vet crap” at that. And then they are in Alberta, Canada and you are in Portugal. You can’t get nutritious dog food closer to home?

  45. Galadriel,

    Sorry, I must not have been very clear. What I was trying to say is that the amount of food fed which maintains an appropriate body weight should be nutritionally complete because that’s how the foods are designed. The amount the manufacturer recommends you feed has nothing to do with that and is, I agree, usually grossly more than needs to be fed to a healthy, normal weight dog.

  46. keleton says:

    I haven’t found a truly science based vet in my area yet since our old one left to become a teacher. They seem to do an adequate job of treating illnesses and injuries but always trying to sell the holistic crap on the side.

    My dog is a 13 year old mutt, has always been free fed, self regulates her weight, but is very picky about the brand of kibble she will eat. We do give her some scraps a few times a day. If her kibble is changed she protests, loses weight, has skin problems, etc. So we just leave well enough alone.

    While working with dogs at a daycare/kennel several years ago I first learned about homemade dog food (several clients), CAM for dogs (also very popular), etc and there were a few clients who fed raw diets. None of their dogs seemed to benefit by it.

  47. wickerman says:

    @Rosemary – I buy orijen or acana (another brand from the same manufacture, but cheaper) from a Spanish website. They deliver at home, p&p free if it’s over 50 euros. I buy a big bag every time.

    It is cheaper than famous brands (Pedigree Pal, Purina, Science Plan, etc.) that are available in physical stores around.

    On their website they claim to follow a lot of regulations – check http://www.orijen.ca/orijen/about/ourQuality.aspx

    One would think it should be true, otherwise other brands would be on their throats.

    They cook the food they make; they don’t seem to be in any way proponents of raw food or other woo, except perhaps the notion that *some* grains (namely corn and wheat) are not good for dogs.
    Please point out the alt-vet crap you found, if other than the no-corn, no-wheat idea.

    Both Orijen and Acana have a detailed FAQ here – http://www.championpetfoods.com/faq/

    I find the ingredients list very satisfactory, and i have never seen a negative review of the food (neither science-based – the ones that matter – nor otherwise). If there’s something wrong with it i would love to hear it. To my mind, human-grade fish and meat is better than “meat sub-products”, whatever that may be.

    Again, let me stress out that i have no conflict of interest, here: i’m an anti-woo, science-based, rational and skeptical person that is not connected *at all* with these brands, but found them, after research, to be satisfactory to me and my dogs.
    Please correct me if i’m wrong.

    Pedro

  48. Galadriel says:

    the amount of food fed which maintains an appropriate body weight should be nutritionally complete because that’s how the foods are designed.

    Ahaaaa. Great. Now that my guys are rather elderly and seem to have more needs, this has been bothering me more. Thank you very much.

  49. harris.skeptic says:

    Any nutrient from a grain is presumed by some to have lesser benefit than the same nutrient derived from a meat source. Multiple scientific studies have proven this to be a complete fallacy. There is no “traffic cop” in the stomach that refuses entry for some nutrient derived from grain and permits the passage of the same nutrient derived from a meat source.
    For example a molecule of tryptophan, an important amino acid, whether derived from soy, corn or beef has equal value to the animal.

    The most commonly used grain in pet foods is corn. About 99% or the starch fraction of the grain is digested in dogs. This holds true of nearly all grains. The starch fraction of any grain contributes carbohydrates which are a source of rapidly
    available energy that does not require the kidneys to process it
    before it can be utilized. The protein fraction of corn, which is
    the most digestible of all grains commonly used in pet foods,
    contributes valuable amino acid building blocks. Grains like corn
    also contribute high levels of naturally occurring Omega Fatty acids and the antioxidant lutein, critical for long term health. 100,000 years of genetic mutation and natural selection made it possible for domestic dogs to derive a significant amount of value out of grains.

    [Murray SM, Fahey GC Jr, Merchen NR, Sunvold GD, Reinhart GA
    Evaluation of selected high-starch flours as ingredients in canine
    diets. J Anim Sci 1999 Aug;77(8):2180-6 Department of Animal
    Sciences, University of Illinois, Urbana 61801, USA ]
    http://www.ncbi.nlm.nih.gov/sites/pubmed

    Ron Harris

  50. alison says:

    It’s the same with horses – very few people feed their animals at the rates specified on the bag … and the manufacturers have all these adverts that say “since most people do not give their horses the recommended amount of our feed, they might just be short of an essential vitamin or mineral or two – which we can, conveniently, sell you.” And although horse feed in bags is more expensive than grass or hay, the vitamin supplements are way more expensive. Loads of horse owners don’t think as hard as they should, about this.

  51. wickerman says:

    @harris.skeptic – thanks!

  52. dwinches says:

    Thanks for the review of the arguments and data. My wife and I have been using a raw-food diet (with supplements for nutrients it lacks) not based on homeopathic or other rhetoric but based on the recommendation of a friend. We have not had any difficulty, nor seen any adverse effects in our clinical trial with n=2. Our anecdote is that they are happy and energetic and our vet has not noted any untoward effects. A bonus is that the litter box smell is far less malodorous than when eating kibble.

    I noted the references (ie: read the titles, could not find the original articles full text) about the inherent risks, which seem to be based on basic science nutritional analyses and case reports of infections. This all brings me to just a couple of questions.

    –Has anyone done a randomized trial of kibble vs. raw?

    –If we have settled into a raw diet that is working for us, and the cats are tolerating it without ill effect, is the evidence you cited about risk of infections the strongest data to suggest that we should switch back?

    Thanks for the great article!

  53. tariqata says:

    I’ve been following this with interest. When I first started hearing about raw food diets (my roommate worked in a pet supply store), I started to wonder if my family was harming our dog by feeding him a cheap commercial kibble from the grocery store. But since he lived to be over 16 – which is pretty good for a mostly Labrador, as I understand it – I decided we were probably not abusing him.

    I do admit to being rather disturbed by the vegan cat food I see advertised at events like the Toronto Vegetarian Fair, though. Even knowing that there’s plenty of grain in commercial cat food (even in the not-so-cheap kibble I feed my cat), it just doesn’t seem like it could be nutritionally adequate. I’d be curious if anyone knows whether it is.

  54. @dwinches,

    As I mentioned in the article and in earlier comments, the way I see raw diets is that 1) they have no demonstrated benefits, only theoretical benefits based on implausible or erroneous arguments and 2) they have documented risks, including infectious and parasitic disease in pets and humans, nutritional inadequacy, and concerns about trauma from raw bones. I suspect these risks are low, but without any controlled research no one really knows. There is not any feeding trial evidence to compare homemade or commercial raw diets and conventional commercial foods (and note, these included canned foods, not just kibble, and there is a separate set of issues concerning the pros and cons of each of these).

    On this basis, I don’t recommend raw diets, but I understand that in the absence of any apparent problems many people already feeding them will not see the risk/benefit ratio alone as sufficient reason to change. In that case, what I recommend is that you follow FDA guidelines for handling raw meat, that you have your cats examined annually and screened or treated for parasitic or infectious diseases if they show any signs of food-borne illness (e.g. vomiting, diarrhea), and that you consult with a veterinary nutritionist to ensure the diet is nutritionally appropriate (there are a number you can consult online, or you can get a referral from your veterinarian).

  55. @tariqata
    Vegan diets for cats have been formulated to meet published nutrient requirements for cats, but it is doubtful that they are both truly free of animal products and nutritionally adequate. Some companies add arachidonic acid to their vegan diets, and there is no known non-animal source of this. Most of the nutrients cats require that are missing from plant sources are added as synthetic chemicals, which creates an interesting conundrum for those who want to feed “natural” and vegan. And the few that have been analyzed simmply did not meet the nutritional requirements of cats as claimed:

    Nutritional adequacy of two vegan diets for cats
    J Am Vet Med Assoc. December 2004;225(11):1670-5.
    Christina M Gray1, Rance K Sellon, Lisa M Freeman
    1 Department of Veterinary Clinical Sciences, College of Veterinary Medicine, Washington State University, Pullman, WA 99164-7010, USA.

    Abstract
    People have a long history of consuming vegetarian diets, and the population of humans who are vegetarians appears to be growing. In a 2002 poll, 4% of Americans considered themselves to be vegetarians. However, vegetarianism comprises a wide range of dietary beliefs and practices. Some of the more common types include ovovegetarians, who eat vegetables and eggs, and lactovegetarians, who eat vegetables and dairy products. The strictest form of vegetarianism is veganism. A vegan excludes meat, seafood, eggs, dairy products, and all other animal products from the diet. Reasons for adopting any of the many vegetarian diets include health as well as religious and ethical concerns. Ethical beliefs are a common reason for people to adopt a vegan lifestyle and to eliminate all animal products from their diet. Some so wish to distance themselves from any sort of animal consumption that they elect to feed their dogs and cats a diet free of animal products. To our knowledge, the health and safety of vegan diets has not been determined for dogs or cats, and this issue is of particular concern for cats. The 2 vegan diets (diets Ab and Bc) analyzed and described here did not meet the minimum nutrient amounts cited in the Association of American Feed Control Officials (AAFCO) Cat Food Nutrient Profiles and thus cannot be recommended as a sole source of nutrition for cats. The premise of the food manufacturers that their vegan diets can meet 100 % of a cat’s nutritional needs was not supported by an independent dietary analysis. Despite obvious differences, all parties interested in this issue are united by a common concern for the welfare of cats. Thus, veterinarians have an important role to play in helping cat owners to understand the unique nutritional requirements of cats so that a diet can be chosen on the basis of the most complete information possible. b Vegecat Kibblemix, Harbingers of a New Age, Troy, Mont. c Evolution diet vegan gourmet vegetable strew entree, Evolution Diet, Saint Paul, Minn

  56. dwinches says:

    Thanks a lot, again, very helpful.

  57. rosemary says:

    Pedro

    From the site you posted:
    http://www.orijen.ca/orijen/products/
    “The Biologically Appropriate concept is simple: in correct ratio and quantity, include the fresh, whole foods that nature evolved dogs and cats to eat while excluding ingredients like cereal grains that are not part of the natural diet.”

    The implication is that fresh and whole are best because they are “natural” and that the products the company sells contain “fresh, whole” ingredients when their products are processed. The implication is that the freshness and wholeness of the things they start with will survive the manufacturing procedures and be superior to other products that start with raw materials that aren’t all that fresh or whole when actually, aside from contaminants, it doesn’t matter what goes in. It matters what comes out. What comes out has to contain all the essential nutrients the animal needs in the amounts that he needs them in.

    http://www.orijen.ca/orijen/freshRegionalIngredients/
    “Reflecting the natural diet, ORIJEN foods contain a diversity of fresh meat ingredients – sustainably fished or farmed by people we know and trust, and delivered to our door fresh (never-frozen) each day…Certified free of antibiotics and artificial growth hormones, our meat ingredients are produced exclusively from animals passed as ‘fit for human consumption’ by the Government of Canada.”

    They trust the ingredients in their products because they get them from locals that they know. Fair enough. But then they expect you to trust them, a company that you don’t know because it is thousands of miles away. They value sustainability and by implication the environment. But how much energy does it take to ship their products half way around the world to customers? Does doing that help the environment or encourage sustainable agriculture where their customers live?

    “Fit for human consumption,” does that mean they don’t realize that the nutritional needs of each species vary and that dogs are not cats and that neither is human? Their products should be fit for consumption by the species they are intended for.

    Why is it important that the ingredients are “never frozen”? I know some humans prefer fish and produce that has never been frozen because they believe it tastes better. Do animals notice that? If so, does it matter? I believe that some people claim that freezing is a very good way to maintain the nutritional value of food.

    You say that the products are reasonably priced. Unless other pet food manufacturers make outrageously huge profits, I simply cannot understand how a company could sell a pet food for a competitive price when they buy high quality, human grade raw material from local producers, manufacture it themselves in a small factory and ship it halfway round the world. And furthermore, if in fact they do that and if the product becomes very popular wouldn’t that put an added burden on the world’s human food supply, as implied in the NYTs article I linked to?

    While my guess is that the company is simply doing slick marketing for a very upscale market, all their buzz words are those used by alt vets – natural diet, whole, human grade, plus the scare tactics – “antibiotic free”, “no artificial growth hormones”. Is there evidence that either are bad for dogs or cats at the levels found in most pet food? And how about “natural growth hormones”? Do they check those levels or are only the artificial kind bad in excess?

    You said that you thought that if the company wasn’t doing what it claims that competitors would expose them. I don’t think they would do that unless they got to a point where they were actually getting a big piece of the pet food market pie. Till then they won’t be on the radar.

  58. wickerman says:

    @Rosemary:

    You said: “The implication is that fresh and whole are best because they are “natural” and that the products the company sells contain “fresh, whole” ingredients when their products are processed.”

    I have no idea what the implication is, for them. To my mind, it means food that they can confirm its in good condition.

    Then you said: “it doesn’t matter what goes in. It matters what comes out. What comes out has to contain all the essential nutrients the animal needs in the amounts that he needs them in.”

    I agree 100%.

    Then: “then they expect you to trust them, a company that you don’t know because it is thousands of miles away.”

    And that happens with all companies that i engage with, by buying stuff or services. Trust, in those conditions, arises from a number of factors.

    Then:
    “They value sustainability and by implication the environment. But how much energy does it take to ship their products half way around the world to customers? Does doing that help the environment or encourage sustainable agriculture where their customers live?”

    I don’t really care about those issues – the fact that they have those values doesn’t mean i share them.

    Then:
    ” “Fit for human consumption,” does that mean they don’t realize that the nutritional needs of each species vary and that dogs are not cats and that neither is human? Their products should be fit for consumption by the species they are intended for.”

    Maybe you’re missing the point, or maybe you see it differently. Fit for human consumption means, as far as i can tell, fitting-a-safety-and-quality-bill-that-will-make-Fido’s-owner-not-worry-that-Fido-is-eating-god-knows-what. It has nothing to do with species and their needs.

    The never-frozen argument seems silly to me too, i agree with you on that.

    Then:
    “You say that the products are reasonably priced.”

    Yes, they are. Please compare these 4 basic products; food for adult dogs, the “regular” variety for each brand. First, Orijen and Acana, then top name brands, no supermarket junk, Eukanuba and Hill’s (Science Plan)

    Orijen Adult – 62.97 Euros for 13,5 Kg – 4,664 euros per kilogram –
    http://www.mascotaplanet.com/catalog/orijen-adult-alimento-para-perros-adultos-p-3298.html

    Acana Adult Dog – 46,75 Euros for 13,5 kg – 3,462 euros per kilogram –
    http://www.mascotaplanet.com/catalog/acana-adult-mantenimiento-premium-p-3149.html

    Eukanuba Adult – 65,93 Euros for 15k – that’s 4,395 Euros per kilogram. –
    http://www.mascotaplanet.com/catalog/eukanuba-adult-medium-mantenimiento-p-278.html

    Hill’s Canine Adult – 65.98 euros for 15 kg – that’s 4,398 Euros per kilogram –
    http://www.mascotaplanet.com/catalog/hills-canine-adult-ternera-p-327.html

    As you can see, the Orijen bag is more expensive than the others, but then again it comes from Canada, not somewhere in Spain. The Acana one, on the other hand, and although coming from Canada as well, is cheaper than the other ones!
    Let’s compare ingredients and nutritional value on the Acana, the Eukanuba and the Hill’s one, shall we?

    Acana’s – http://www.dogfoodanalysis.com/dog_food_reviews/showproduct.php/product/2250/cat/4

    Eukanuba’s – http://www.dogfoodanalysis.com/dog_food_reviews/showproduct.php?product=107&cat=all

    Hill’s – http://www.dogfoodanalysis.com/dog_food_reviews/showproduct.php?product=131&cat=all

    Now, if i can give my dogs Chicken meal, steamed oats, chicken, peas, brown rice, chicken fat, deboned salmon, chicken
    liver, whole eggs, sun-cured alfalfa, salmon oil, pumpkin, chicken cartilage, apples, carrots, turnip greens,
    cranberries, Saskatoon berries, etc,

    instead of Corn meal, chicken by-product meal (?!?), animal fat (can one be more generic?), dried beet pulp, vegetable oil (how many times re-fried?), dried egg product, etc.

    or Chicken, Chicken By-Product Meal (by-product? uhm…), Corn Meal, Ground Whole Grain Sorghum, Ground Whole Grain Barley, Fish Meal, etc,

    for LESS money (i’m buying Acana, not Orijen, because i’m not too wealthy right now), despite some wacko claims those guys may have, i’m doing it. It’s good food at a nice price.

    Regarding the human food supply, i have two ideas: responsibly genetic engineered crops and more humans focusing on vegetable rather than animal food sources (i’m a vegetarian myself).
    Besides, no one in Canada – or anywhere else – is hungry because the ingredients that should be on her plate are on a dog’s. I think that’s an ideological, not rational argument.

    Finally, you said:
    “(…)that competitors would expose them. I don’t think they would do that unless they got to a point where they were actually getting a big piece of the pet food market pie. Till then they won’t be on the radar.”
    Well, they did won the Pet food of the year award, 2010-2011
    given by the Glycemic Research Institute of Washington DC. Plus, they have a huge score (6 stars for Orijen and 4 stars for Acana) on http://www.dogfoodanalysis.com – i’m pretty sure they are big enough to be an enemy to other companies.

    All in all, what i think (as of now) is this: this is good food at a cheaper (Acana, again, not Orijen) price than brand-name food (i’m not even going to mention supermarket generic brands). They do have some wacky ideas that are not supported by science but it does not change the fact that the food is of great quality and balanced. As a plus, at least the only organic (a fad I dislike) ingredients they have are seaweeds – if you stick your hand out at sea and grab some kelp, bam!, there’s organic kelp for you.
    With all that in mind, i see no reason to give this food that the dogs, by the way, just love to eat.

  59. tariqata says:

    Brennen: Thanks. I’ve seen vegan cat food being promoted rather often, and although I’m sad to see presumed animal lovers promoting something that isn’t necessarily best for cats, it’s good to know, anyway.

  60. rosemary says:

    I googled “Charlie Kaufmann Champion Petfoods” (Orijen) and came up with some interesting things although I have no idea how accurate they are. I assume that the odds of those from the periodicals being accurate are higher than those from the forums, but even they could contain errors.

    Several dog forums reported sharp bones in kibble and posted what they said was Charlie’s reply. As i said, I have no idea if this is true or if it is if the bones would have posed any danger to dogs who consumed them. What i found interesting was that Charlie blamed the problem on a malfunction of the equipment that his supplier used to process the salmon. I find that interesting since his website definitely indicates that whole foods are delivered fresh to his plant where the company processes them.
    http://www.dogforums.com/5-dog-food-forum/27683-orijen-concern-please-read.html

    There was a report about the brand being pulled from the Australian market because Orijen caused serious illness and even death in several cats. The company is reported to have said that the reason was that Australia irradiated the food using dangerously high doses. However, I assume that if that is correct that Australia does the same with all cat foods and wonder why no other company appears to have had the same problems.
    http://www.petproductnews.com/headlines/2008/12/01/champion-petfoods-pulls-out-of-australian-market.aspx

    This site says that they use “herbs & botanicals” in their food. I doubt that those ingredients have been tested in dogs and cats. Adding “dietary supplements”, if that is what they are, is all part of the game played by alt vet medders to create an aura of health.
    http://investing.businessweek.com/research/stocks/private/snapshot.asp?privcapId=30825663

    Once more I have not verified any of this independently but in addition to the website it all raises red flags for me.

  61. tariqata “I’ve seen vegan cat food being promoted rather often, and although I’m sad to see presumed animal lovers promoting something that isn’t necessarily best for cats, it’s good to know, anyway.”

    I agree. I would think if someone has an ethical concern with eating meat, that they should strongly consider not having a carnivore as a pet.

    A domestic rabbit and/or some birds can make very nice pets when properly socialized. And there are often bunnies looking for homes in shelters or other pet placement organizations.

  62. BillyJoe says:

    Can you house-train a rabbit?

  63. Enkidu says:

    Re: free-feeding dogs

    This is such a foreign concept in my house. All four of my dogs inhale their food about 3.2 seconds after I put the bowl in front of them. They get breakfast and dinner, and treats in-between, yet every meal they act like they will never get another.

    A few weeks ago my 9 year old collie mix got into the pantry and ate about 6 lbs of dry dog food. It looked like he swallowed a bowling ball! He is fine now (after a trip to the ER to administer some IV fluids). And I know if I left the pantry door open again, history would surely repeat itself!

    Oh, and for the record, my dogs all eat dry dog food. The two oldest (an elkhound aged 13 and the collie mix) eat prescription food for arthritis, my middle-aged girl (a 6 year old corgi-chow mix) is on prescription food for bladder stones, and my youngest (a 5 year old whippet mix) gets Wellness brand.

  64. rosemary says:

    Enkidu, in my experience your dogs are typical. (I’ve got a lot of experience. The kennel I help out in sometimes can have 80 to 100 dogs over a busy holiday.) But I’ve always free feed my own dogs, several of whom were mixed breeds. However, because I also have cats, I’ve always gotten the dogs very young, about 9 weeks of age.

    Then there was my friend’s Saluki. When I cared for him, he would lounge on a futon, hope off, trot to the bowl, take one piece of kibble, trot back to the futon, jump over the arm, lay down and eat that one piece of kibble. That was repeated throughout the day. But he loved to steal. If my friend put food on a counter that he could reach and my friend turned his back, the food was gone although the Saluki didn’t always eat it himself. He often gave it to my friend’s Min Pins who have gorged themselves several times just like the dog you took to the ER did.

  65. Seandc says:

    I’m semi new to this site, but I found this article interesting enough that I felt the need to comment. The primary idea here draws a lot of parallels with a friend of mine that is now of the mindset that eating only raw foods will somehow make him healthier, and can even cure diabetes, cancer and other diseases. I’ve been trying to find hard data to support my argument that he is wrong, or at least that there is plenty of valid scientific data that disproves the idea that eating raw meat and unpasteurized dairy products will make him healthier.

    At first I expected to quickly prove him wrong when he got sick, but he actually hasn’t gotten sick from his diet which he has been on for +2 years. I’ve looked but haven’t been able to find any studies that provide information relating to long term consumption of raw meat/ unpasteurized dairy products and their effects on a persons overall health in comparison to a “regular” diet.

    Any help or links to an article relating to this would be greatly appreciated. Thank you. =-)

  66. rosemary says:

    Pedro,
    http://www.dogforums.com/5-dog-food-forum/27683-orijen-concern-please-read.html
    “It is true that there was a limited amount of ORIJEN made with some fresh salmon that accidentally had some fragments of salmon bone in it. The supplier of the fresh salmon experienced some mechanical difficulties with their process…The problem was immediately pointed out to the supplier and the problem was fixed right after.” From a letter from Charlie Kaufmann, the manufacturer.

    That leads me to believe that the chances are very high that Nestle was correct about all pet food, including this brand, being made from the byproducts of human food production regardless of the manufacturers’ claims to the contrary. It would also explain why their “meat ingredients are produced exclusively from animals passed as ‘fit for human consumption’ by the Government of Canada,” and the reason why they can competitively price their products.

    http://www.nytimes.com/2010/06/01/health/01brod.html
    If you scroll down, you will see, “’All pet foods are made from the byproducts of human food production,’ Dr. Nestle explained. ‘No matter what the package says, your dog is not getting whole chicken breasts, but what remains after the breasts have been removed for human food.’”

    Regarding your desire to give your dogs food you believe is made from whole foods “instead of Corn meal, chicken by-product meal (?!?), animal fat (can one be more generic?), dried beet pulp, vegetable oil (how many times re-fried?), dried egg product, etc,” I think that Harris.skeptic said it best, “Any nutrient from a grain is presumed by some to have lesser benefit than the same nutrient derived from a meat source. Multiple scientific studies have proven this to be a complete fallacy. There is no “traffic cop” in the stomach that refuses entry for some nutrient derived from grain and permits the passage of the same nutrient derived from a meat source.” Scientists tell us that applies to all nutrients while alts claim that nutrients coming from “whole” & “natural” foods are superior. They do the same about botanical supplements and drugs claiming that the botanicals are superior because of their origins. They are superior because they’ve been manufactured by dear old Mother Nature rather than the dirty hands of men.

    And there is no need to compare nutrients from brand to brand. What counts is that the end product, the food, is “complete and balanced”.

  67. art malernee dvm says:

    I tell my clients that testing by independent labs like those of Consumer Reports magazine show that the definition of premium dog and cat food is food you pay a premium for. This includes food you can only buy at the veterinarians office that Walmart sells with about or exactly the same formula for about half the amount. There are no perscription foods. RX pet food is only a marketing term veterinarians use to sell dog and cat food out of their office.

    art malernee dvm
    fla lic 1820

  68. Kylara says:

    @Alison, regarding coat — my overweight cat was just at the vet and I mentioned his dandruff, and the vet said that that’s really common in cats eating the “weight reduction” kibbles, because they’re low in oils and fats. So that’s probably part of your answer … the diet is nutritionally complete for my cat, and good for him because he needs to lose weight (the big chunk!), but more oils would make his coat silkier and involve less dandruff.

    As a side note, one of my little obligate carnivores (cats) categorically refuses meat and fish of all sorts. No interest at all. If he were on a raw diet — or even a cooked meat diet! — he’d starve. Perhaps nobody has informed him of his carnivorous obligations. :) I used to have a cat who was relatively indifferent to meat — he could take it or leave it — but would lick all the hot wing coating off hotwings and leave the wing intact (if I made the mistake of leaving my wings unattended), and would do ANYTHING to get at a cantaloupe. My overweight cat is crazy for lettuce.

  69. Scott says:

    That is not entirely correct.
    A very powerful anecdote can overcome that reticence.
    After seeing some patients with RIF pain die, I guess the first surgeon who operated on such a patient, found an inflammed appendix, and removed it, would not do a controlled clinical trial before he trusted his anecdote to try this on all his subsequent patients with RIF pain.
    (Of course, failing to find an inflammed appendix in some of these patients, probably led to stricter selection criteria over time)

    If properly and rigorously documented and reported, that’s a case study not an anecdote. And if NOT so documented and reported, then it is indeed an anecdote which would be properly disregarded.

  70. Calli Arcale says:

    SeandC:

    At first I expected to quickly prove him wrong when he got sick, but he actually hasn’t gotten sick from his diet which he has been on for +2 years. I’ve looked but haven’t been able to find any studies that provide information relating to long term consumption of raw meat/ unpasteurized dairy products and their effects on a persons overall health in comparison to a “regular” diet.

    I don’t have any links for you, but raw food is not, in and of itself, bad for you. It’s the pathogens it can carry that are bad for you. So it’s a game of Russian Roulette, really. Your friend could go for decades without getting sick. Or he could contract a fatal case of salmonella tomorrow. There’s really no good way to predict it. Keeping the food clean and avoiding cross contamination helps a lot, but it doesn’t take the risk down to zero. Given enough time, his number will probably come up. I guess the question is, does he feel lucky?

    I eat sashimi every now and again, and I’ve eaten steak tartare. Both have some risk associated with them. I’ve not gotten sick from either, but there is en element of luck involved. I wouldn’t make my entire diet be raw food.

    Cooking does have other advantages, namely that it makes some nutrients much more available. Ruminants ferment their food in their stomachs; we process and cook ours. Basically, processing and cooking is doing some of the digesting ahead of time, increasing the overall effectiveness of the process. And therein lies the real problem with processed and cooked foods: now that we have an overabundance of food, getting every last bit of nutrition maybe isn’t such a good thing. We’re getting fat!

  71. A. Noyd says:

    wickerman

    If there’s something wrong with it i would love to hear it. To my mind, human-grade fish and meat is better than “meat sub-products”, whatever that may be.

    Those terms were explained by Dr. McKenzie here. Meat by-products are not, as you mention elsewhere, “god-knows-what.” What makes “human grade meat” is in large part a culturally based aesthetic rather than anything practical. In other words, we choose not to eat many perfectly edible organ meats or other body parts simply because they gross us out. You’re ignoring the science to make a nutritionally unnecessary aesthetic choice for your dog. Furthermore, if everyone thought their pets were better off with “human grade meats,” then we would require more food animals raised and slaughtered and more wastage.

  72. @art

    As far as “prescription” diets sold through veterinarians are concerned, the legal and regulatory waters are quite muddy. This link

    http://www.michigan.gov/documents/Interpreting_Pet_Food_Labels_-_Part_2_(DD)_125169_7.pdf

    gives a pretty good summary, but the law is not entirely clear. Under some interpretations, making a health claim for a diet could be construed as subjecting the diet to “drug” status, which requires stringent pre-market approval testing. Most diets designed to be used only in specific disease conditions, such as protein/phosphorus restricted diets for use in patients with kidney failure, are still regulated as foods, subject to AAFCO nutritonal standfards, but they are sold exclusively through veterinarians because it is recognized that they are not nutritionally appropriate for pets without specific medical conditions.

    For some of these diets, there is good evidence of medical benefit (e.g. Ross SJ, Osborne CA, Kirk CA, Lowry SR, Koehler LA, Polzin DJ. Clinical evaluation of dietary modification for treatment of spontaneous chronic kidney disease in cats.J Am Vet Med Assoc. 2006 Sep 15;229(6):949-57.) Not all such diets, of course, have such independant evidence of benefit.

    The suggestion that the practice of limiting sale of such diets to veterinarians with an established veterinarian/client/patient relationship is only a marketing strategy is not correct. These diets could do harm if used inappropriately, so while they are not strictly regulated as drugs there is a sound rationale for requiring veterinary supervision of their use.

  73. art malernee dvm says:

    These diets could do harm if used inappropriately, so while they are not strictly regulated as drugs there is a sound rationale for requiring veterinary supervision of their use.>>>

    Since single source maintenance diets are a risk factor for disease. ANY single source diet not used for intermittent feeding could do harm and should be under the supervision of a doctor. The problem occurs when the doctor sell these “muddy water” diets that have not been proven safe and effective as a single source diet. Your physician does not tell you to only eat out of this special bag of food he or she sells in the waiting room of the office that only physician sell.

    LABEL
    Prescription Diet brand dietary animal foods are scientifically formulated for the nutritional management of dogs and cats with specific conditions and therefore, are authorized for sale only by veterinarians. This food is intended for intermittent feeding only or as directed by your veterinarian.

    art malernee dvm
    fla lic 1820

  74. Grumpy Grampy says:

    Did any of you youngsters who were suckled on TV ever wonder how the canine species managed to evolve without kibble? Do you think their digestive tract underwent gradual change in the past 100 years? McDonalds for you, kibble for your dog, and a cell phone implanted in your child at birth…

  75. rosemary says:

    Grumpy Grampy, “Did any of you youngsters who were suckled on TV ever wonder how the canine species managed to evolve without kibble?”

    Maybe by dying young and reproducing rapidly the way our barn cats still do? Actually, I was raised without a TV and none of our dogs was ever fed a “raw diet”.

  76. wickerman says:

    @ Noyd and Rosemary – sorry for the delay, folks; real life got in the way.
    What you’ve written seemed interesting and though-provoking. I’m going to sleep on it. Thank you!

  77. harris.skeptic says:

    Evidence is also mounting of other issues relative to BARF feeding. Renal failure is the 3rd most common cause of disease death in dogs and the 2nd most common in cats. In a large study conducted by Dr. Joe Bartges, Dr. Jean Dodds and Dr. Susan Wynn, they looked at bloodwork from over 200 BARF dogs, and compared it to 75 dogs eating ‘normal’ diets and used by the lab for reference values. Mean BUN (blood urea nitrogen) was indeed significantly higher in dogs eating the BARF diet. Increased BUN is one of the most critical values examined when looking for renal failure. This certainly is a significant warning of impending danger in older geriatric dogs with undetected renal failure.

    In a study done by the veterinary school in Banglaore India
    comparing a meat based homemade diet versus a commercial diet, the homemade diet increased renal disease (renal failure, nephritis, cystitis, and urinary calculi) by 43%.

    In the process of proclaiming great value to the BARF diet,
    proponents completely ignore one of the most common causes of death in domestic pets – renal (kidney) failure. In most cases the proposed diet recipes are excessive in calcium and phosphorous. While there is no data that shows the feeding of high levels of phosphorous will cause renal failure, there is a mountain of data which clearly shows renal failure can be greatly exacerbated by feeding such a diet. Most veterinary hospitals are unable to detect renal failure until 70% of the kidney is destroyed. Barfer’s tend to concern themselves with internet fantasy diseases purported to be caused by artificial antioxidants and totally ignore real disease like renal failure.

    Ron

  78. professional_lurker says:

    This this is probably worth a read.

  79. professional_lurker says:

    I’m also having difficulty understanding why you would compare wolves in the wild to those held in captivity? I mean, the confounders are so numerous… it’s probably a lot easier to pounce around, not having to compete for pack order or worry about predators knocking you off while you sleep. And wolves that are in captivity probably have access to adequate care, but also receive it on a daily basis. Do you think that might contribute to life span regardless of diet?

    Wolves are highly adaptable and can sustain on suboptimal foods, just like humans.

  80. professional_lurker says:

    @Norris up yonder

    It s not unusual that the reason for this is due to the dog being given bones such as a lamb shank, which, with its triangular cross section at the proximal end is a great shape of bone to fracture a tooth.

    Responsible raw feeding does not include the use of this kind of recreational bone without supervision, and only then, on a limited basis. Considering my brother’s dog fractured its tooth on the lumber pile he left in his backyard, I think it’s fair to say that the evidence is sorely lacking for this happening as regularly as you seem to purport that it does.

    And I think it’s also fair to say that most periodontal disease belongs to the kibble fed pet (it has in my experience, and I’ve cleaned many a tooth). No worries either way, Abbot’s got a vax (periovac) for periodontal disease :)

    Sorry for the flood folks.

  81. RE wolves being carried off by predators in their sleep:

    Is that really an issue? Do wolves commonly die of predation, whether while asleep or awake?

    Lying cozily in my bed and thinking about the dogs lolling at my feet, these are the causes of death I would imagine for a wild wolf:
    Starvation (tooth loss or breakage)
    Starvation (hard winter or dry summer)
    Injury (by prey or other wolves)
    Disease (contagious or water-, insect- or food-borne)
    Exposure (isolation from the pack in prolonged cold weather)

    I’m sure there are others, but being carried off by a hungry bear or badger is not what comes first to mind.

    I mention this primarily because much off-hand speculation about selection pressure shaping modern humans assumes tiger predation to have been a primary cause of death for early humans, and this has always bothered me.

    Really? Tiger predation?

    Tigers live in forests and dense brush and early humans migrated along shorelines, so this is certainly possible as tigers could have snatched humans going into the water near deltas. (They still do, especially in areas where humans encroach on their habitat, displacing their natural prey. Bangladesh seems to be a hotspot for modern tiger predation.)

    But what else would I think of for early human causes of death?

    Well, all the wolf ones listed above. Also:
    Childbirth.
    Murder. (A lot of old bodies seem to have been murdered, and many modern hunter-gatherers seem quite murderous.)
    Drowning.
    Accidental injury.

    While a lone, unarmed human would certainly be a more attractive lunch for a tiger than a wolf (rarely or never unarmed) would be for a bear or a badger, tigers today don’t seem that interested in eating us (with the exception of Bangladeshis near deltas being a minor part of local tiger diets). Was tiger predation really that formative in our evolution?

    And was predation by anything at all really that formative in wolf evolution?

  82. harris.skeptic says:

    There is nothing “responsible” about feeding dogs a raw food diet.

    “The oral status of an entire pack of 67 English foxhounds was
    assessed. The dogs were fed solely on raw animal carcasses. The animals did not have healthy oral cavities and all animals had signs of periodontal disease. In addition to periodontal disease, the dogs had a high incidence of traumatic tooth crown fractures.”

    [Robinson JGA, Gorrel C. The oral status of a pack of foxhounds fed a "natural" diet (abstract). Proceedings. Fifth World Veterinary Dental Congress. Birmingham, England, 1997.]

    Since the modern wolf was not exposed to 100,000 years of eating human trash, the development of it’s nutritional needs was not altered in the same manner as dogs. To expect these two different species to have the same nutritional needs is simply not substantiated in history, science or logic.

    Ron Harris

  83. Jurjen S. says:

    Certainly, raw meat and bones are often used as enrichment items or bait for husbandry purposes, but always with an awareness of the risks they pose, and never as the primary diet. 10-12

    I have to take issue with that assertion. I work as a volunteer tour guide at a wolf sanctuary (Wolf Haven in Tenino, WA), and our captive gray wolves are primarily fed a raw meat: 10 lbs of beef on Tuesdays, and one or two (depending on the needs of the individual wolf) entire (cut up) chickens on Fridays. Regular dog food is a fallback option if money is short, or if the particular needs of an individual animal require.

    You’ll notice that two of your three references there are for red wolves (Canis rufus) and Mexican gray wolves (C. lupus baileyi). And yes, the small number of reds and Mexican grays we also have are indeed primarily fed commercial dog food. But it should be noted that the members of this species and subspecies, resp., all are part of captive breeding populations, having both been pulled back from the brink of extinction in the 1970s. As such, each individual member of both captive populations is slated, in principle, for release into the wild; accordingly, they cannot be fed meat from domestic livestock and poultry, lest they develop a taste for it that will cause them to run afoul of ranchers/farmers in the event they are released.

    Moreover, because the populations are extremely small (we’re talking ~160 reds, and ~320 Mexican grays in captivity, and fewer than 100 of each in the wild), their diet has to be carefully monitored; anything that causes an adverse effect in one individual may affect the entire population, so they all need to be eating more or less the same thing, and the easiest way to achieve that is by feeding them all the exact same commercial dog food.

    Your third reference is for the maned wolf, which is native to South America, and only very distantly related to C. lupus (and by extension, domestic dogs), so considerations that apply to maned “wolves” by no means apply to gray wolves or domestic dogs.

    While I cannot dispute your points regarding the dietary requirements of domestic dogs, I’m not convinced of your claims regarding the dietary requirements of captive wolves; at least, not on the basis of husbandry manuals for two very specific, and relatively very small, sub-populations.

  84. professional_lurker says:

    Ron Harris,

    Your evidence is pretty meaningless without a control group.

    Good grief Alison. Can we agree that there might be more exposure to the ‘world’ in the wild and it very well might contain an animal that might provoke an altercation no matter who is considered the ‘predator’?

  85. “Can we agree that there might be more exposure to the ‘world’ in the wild and it very well might contain an animal that might provoke an altercation?”

    Yes, totally. I would expect that wild wolves are commonly injured by their prey, for instance. And that murder by other wolves, while perhaps not common, probably does occur.

    However, you were quite specific in your statement: “it’s probably a lot easier to pounce around, not having to compete for pack order or worry about predators knocking you off while you sleep.”

    Altercation and predation are not the same thing. If I were a wild wolf I’m not sure what animal I would be worried about eating me while I slept, but that was the specific concern that you raised. (RE competing for pack order: in the wild this is usually well-regulated. If wolves killing eachother for pack order were a major cause of concern in daily life they would probably exterminate themselves. For captive wolves I would worry that a solitary wolf would be stressed and that membership in a pack would be more reassuring to the wolf. Membership entails knowing your place. So without evidence I’m not convinced that removing pack order from the list of a wolf’s concerns – solitary confinement – necessarily lengthens its life. It could, of course.)

    I wouldn’t have brought it up except that it’s an example of people trying to imagine the past and, not knowing what real dangers existed, postulate “tigers” or unnamed predators as stand-ins for whatever might have been the actual dangers (which, for all I know, included predators). That in itself wouldn’t be such a problem except that people then try to draw conclusions from the premise that our lives were dominated by the need to run from tigers. Which they probably weren’t.

    As an aside, we are good but not fast runners. Almost completely useless when it comes to getting away from tigers. From wikipedia: “The fastest human footspeed on record is 44.72 km/h (27.79 mph), seen during a 100 meter sprint (average speed between the 60th and the 80th meter) by Usain Bolt.” The comparable top speed of a tiger is 35 mph. And tigers are really good at climbing trees, so a human sprinting to a tree and climbing it isn’t going to be safe. On the other hand, we can keep going at a steady jog for quite a distance.

    An interpretation of the purpose of running more consistent with what we know about our history and environment is that we are built to run toward something, not away from it. For instance, a carcass that has been brought down by another predator, as evidenced by hovering vultures. You want to get there before all the meat is gone, so you don’t want to just meander on over. But if you are completely tuckered out by the time you get there you’ll be too tired to drive off the other scavengers.

    Anyway. This is completely off-topic, but waving hands vaguely in the direction of “predators” instead of investigating actual causes of morbidity and mortality is a personal annoyance of mine. professional_lurker, I’m afraid you have the unfortunate distinction of being the first person I’ve vented at about it. And you weren’t even talking about tigers and human evolutionary psychology. Sorry!

  86. … waving hands vaguely in the direction of “predators” instead of investigating actual causes of morbidity and mortality is a personal annoyance of mine.

    And instead of thinking of alternative explanations for traits like vigilance, for instance. A rabbit is vigilant because it needs to hide from hawks. But we are more likely to be vigilant primarily because we need to see prey to catch it, secondarily to avoid being murdered or raped by someone from another group in the area, and only thirdly because tigers are chasing us. Rabbits don’t have these other concerns: their food doesn’t move and they aren’t particularly murderous.

  87. Jurjen S. says:

    If I can weigh in here for a moment, wolves are apex predators; they’re at the top of the food chain. Carnivores generally don’t taste very good, and there’s nothing I can think of that will actively prey on wolves as a food source.

    Alison’s got it more or less right: the primary causes of death for gray wolves in the wild are starvation, disease and injury. Injury is usually incurred from prey defending itself (e.g. deer, elk, moose, bighorn sheep), other predators when disputing a kill (e.g. wolverines and cougars), or when a lone wolf strays into the territory of another pack (which is a very rare occurrence). And, of course, from humans.

    In the wild, gray wolves usually live 5-9 years (they become sexually mature at 2-3 years); they don’t get the chance to die of old age. In captivity, they can make it to 20 or over, though 15 or thereabouts is more typical.

  88. squirrelelite says:

    @Jurjen and others,

    Wolves are apex predators, but like all canines, they are not exclusively carnivores (unlike cats). That is why they have some grinding teeth.

    A couple quotes from the Wikipedia article make this point.

    http://www.bing.com/reference/semhtml/?title=Gray_Wolf&src=abop&qpvt=wolves&fwd=1&q=wolves

    “Wolves feed primarily on medium to large sized ungulates, up to the size of bovines like bison. However, like most predators, they are opportunistic feeders, and will generally eat any meat that is available”

    but

    “Wolves supplement their diet with vegetation. Scat analysis found 75% of samples found Yellowstone National Park wolves’ summer diet contained plants mostly grass (Graminae).[85] In some areas of the former Soviet Union wolves have been reported to cause serious damage to watermelon plantations.”

    They are very closely related to the domestic dog, which is why they pertinent to this thread.

    “Much debate has centered on the relationship between the wolf and the domestic dog, though most authorities see the wolf as the dog’s direct ancestor (see Origin of the domestic dog). Because canids have evolved recently and different species interbreed readily, untangling the relationships has been difficult. However, molecular systematics now indicate very strongly that domestic dogs and wolves are closely related, and the domestic dog is now normally classified as a subspecies of the wolf: Canis lupus familiaris. Additionally, breeding experiments in Germany with poodles, wolves, and later on with the resulting wolf-dogs showed unrestricted fertility, mating via free choice and no significant communication problems (even after a few generations). “

  89. “Wolves are apex predators, but like all canines, they are not exclusively carnivores (unlike cats).”

    I think Jurjen S.’ point was just that an apex carnivore is at the apex of its particular food chain. It eats but is not eaten. It has no predators.

  90. Not sure if this is relevant but, most predators are still must protect young from other predators.

    squirrelelite – so mating has no significant communication problems? They’re doing better than homo sapian then. :)

  91. squirrelelite says:

    Yes, Alison.

    I haven’t followed this whole thread (I spent a couple of days resuscitating a computer), but it seemed to me that several of the commenters (and the advocates for the BARF diet) were referring to them and their domestic cousins as carnivores as if that meant they were exclusively carnivores like cats. And I wanted to point out that distinction.

    For a personal anecdotal report, we have 4 dogs now (or had, one of them is now living with one of my sons) and have raised them mostly on standard commercial dry dog food with occasional treats. They don’t complain about meat and were very happy to clean out the small meat loaf pans I used to make supper last night! We mostly avoid giving them bones because we are concerned about potential internal injuries from swallowing cracked bones.

    The older two like pieces of bread, chips, cookies, and especially leftover pizza crust. The oldest, which is resting in the afternoon heat on the couch a few feet away, had repeated problems with some sort of skin fungus which caused patches in her coat. That was cured after a couple trips to the vet and the oil in the pizza crust helped her coat grow back thick and smooth and not so dry (at least we think so). She probably got it when she was running around wild in the park next door before our kids “rescued” her.

    The younger two seem to like almost any pieces of vegetables that fall to the kitchen floor, whether carrots, asparagus, or even onions?!?!

    Anyway, enough already. Have a good afternoon.

  92. professional_lurker says:

    Alison,

    my apologies, I did in fact (incorrectly) allude to something far more specific… My point was that you simply cannot compare the two (captive wolves and those in the wild), and I was flippant and inaccurate in my assertion. Upon further reading today (Mech, The Wolf), injuries are almost wholly caused by altercations with prey animals. I was too wrapped up in man’s companionship and my usual defense of the life span of man.

    Weaker members of the pack aren’t as likely, as I understand it, to get near as much nourishment regardless of kill. They can and do subsequently suffer from periodontal disease (and other disease associated with malnourishment, etc). It’s not uncommon for packs to go several days without eating, whereas their dietary needs (and medical needs) are better met in captivity, so in my mind they are not comparable no matter how hard you control for confounders.

    I don’t think it’s meaningful to post evidence (the above case series) of periodontal disease among a pack of wolves, without being able to draw a parallel to the counterpart (the kibble fed domestic dog).

    My two cents regarding the word “obligate”: it’s a little obfuscating, simply because if prey is not available, then wolves will forage (do they break down the plant matter?) … but I think given the choice, they’d probably pounce on a herd of deer over a field of alfalfa, while being able to subsist on either.

    Interesting thread.

  93. JM says:

    I was approached at TAM 8 by a friend who knows that I am a vet student with a keen interest in nutrition and asked how I felt about raw diets. I said that I was cautiously in favor of them, as I felt that there was a strong physiological argument in their favor and having had several clients who fed raw successfully, however that without any actual data in favor or against raw diets I could not fully throw my support behind them. Then my friend told me about this article opposed to raw diets and I was a bit taken aback. I was surprised that a blog bearing the name Science Based Medicine would come out strongly opposed to something that we have no controlled studies for and no data to recommend or dissuade against its implementation. I had to see this for myself.

    Let me begin by saying that I am not a woo. In fact, I was fired from my very first position as a veterinary assistant because I expressed skepticism about the applied kinesiology and acupuncture treatments that I was asked to assist with. However, I believe that in our circle of skeptics and science afficianados there is a knee jerk reaction against anything even remotely associated with woo that needs to stop. Yes, if it smells funny we should investigate and hold claims accountable to an equal standard of evidence and plausibility. We should not immediately dismiss them because of their associations, and instead evaluate them based on their own merit. I feel that the tone of this article started off dismissive from the beginning and used quite a bit of fallacious reasoning to make the claims about raw *appear* foolish instead of addressing them head on. Particularly the bit where you said, paraphrasing: “Imagine a pack of chihuahuas taking down an elk. That’s just silly! Clearly they shouldn’t eat what wolves eat.” Non sequiturs such as this are lazy, intellectually dishonest and disappointing to see on a blog such as Science Based Medicine. I expected better.

    The physiological claim that dogs are carnivores and thus should eat meat is, in my opinion, at the very least plausible. Their lack of salivary amylase, their inability to move their jaw laterally which is needed for the grinding of fibrous plant material, their short, smooth GI tract, all point to an animal that is anatomically adapted to a prey-based diet. To me, this should serve as a jumping off point for further study for anyone curious to know the best way to feed our domestic companions. Instead, here you have superficially acknowledged that a physiological basis exists and then completely dismissed it as irrelevant. It is interesting that you provided the example of Great Pandas to demonstrate that physiology doesn’t determine what an animal should eat. I recently took on an independent reasearch study last semester working with several other vet students, grad students and professors to compile natural history information on over 3,000 species to serve as a reference guide for zoos and other captive management programs. Pandas were one of my species of interest and I was immediately deeply curious as to why an animal categorized as a carnivore would consume a diet that is almost entirely comprised of plant material. I read through dozens of journal articles and eventually found that this diet is extremely energetically unfavorable for pandas. They must consume massive amounts of bamboo and spend a much greater amount of their time foraging simply to sustain their basal metabolic rate due to the extremely poor digestibility of their diet. Likely this behavior developed due to the relative abundance of bamboo compared to prey in their environment, however it has had no impact whatsoever on their physiology. They have not developed an enlarged cecum or the microbial ability to handle their high cellulose diet. Thus I believe that pandas are less an example of a carnivore that is misclassified as an example that physiology is the best predictor for what diet an animal is *best* suited for rather that simply what an animal can or will eat. And in fact, zoos often provide meat-based diets for both Red and Great Pandas with bamboo as a supplement for natural foraging behavior, but not as a major component of their diet.

    I was very interested to see your claim that: “Captive wolves live longest and are healthiest when fed — guess what? — commercial dog food!” I was unaware of any studies that have yielded data comparing the relative health and longevity benefits between raw and commercial diets, either on domestic dogs or captive wolves, and so I was excited by the implication that such data exists and quickly scrolled down to obtain and read through references 9-12. Unfortunately I could not find a single reference to a study comparing longevity between wolves fed a commercial dog food vs. a prey model diet. I certainly found the recommendations you mentioned, but nowhere were these recommendations based on any cited, controlled study yielding statistically significant differences in longevity or overall health. Also, at least one of these (the Red Wolf Waddell manual) recommends commercial dry food largely due to the relative difficulty and expense of obtaining whole prey items between facilities in order to establish a uniform diet regimen, not due to any specific health differences between the two. Another of your citations prefaces itself with the following: “Nutritional requirements for Mexican wolves have not been thoroughly studied but are assumed to be similar to those of the domestic dog.” Another uses Maned wolves as the model species, which have a higher capacity for plant material digestibility that is “peculiar to carnivorous animals” (Fowler and Cubas, 2001).

    Recommendations are all well and good, but the problem is that wolf experts vary considerably in their recommendations and base them on personal biases and anecdotes. For every captive wolf expert that recommends a commercial dry dog food diet, there is another who recommends as close to a prey model diet as a facility can provide. Take for example, David Mech, who is considered one of the world’s leading experts in wolf behavior and a supporter of raw diets. I myself have worked with a captive wolf facility, two large feline facilities and a zoo, and all of our carnivores were fed whole carcasses donated by local farms and hunters or commercial, processed raw carnivore diets. Until we have actual data suggesting that one diet is better than another, we can only take recommendations with a grain of salt and regard them as largely anecdotal.

    I have a lot to say on the subject of the level of regulation and testing of the pet food industry. In the interest of brevity in an already too-long comment, however, I will just quote from the FDA’s Pet Food webpage: “There is no requirement that pet food products have pre-market approval by the FDA. Many ingredients such as meat, poultry and grains are considered safe and do not require pre-market approval. Other substances such as minerals, vitamins and other nutrients, flavorings and preservatives, or processing aids may be generally recognized as safe and do not require pre-market approval.” So the level of testing of both ingredients that go into pet food and the foods themselves post-production is extremely questionable to nonexistent. Also, there is some evidence that even with FDA and AAFCO regulations, guidelines and feeding trials, that simply meeting the nutritional requirements is not always enough. You already mentioned the studies on diabetes remission, which has been linked to a simple switch from a high-carbohydrate kibble to a lower carb wet food. Similar results have been found linking chronic renal disease to dry food diets (Jones et al, 1997; Sturgess et al, 2002).

    I would also like to address this claim: “commercial raw diets are seldom tested for nutritional adequacy, and when they have been tested they have usually failed to meet known nutrient requirements.” Both Bravo! And Nature’s Variety, the two most commonly available commercial raw pet food diets sold in stores, process their food following AAFCO guidelines. Nature’s Variety also is the first raw commercial diet to submit its product for an AAFCO feeding trial and passed.

    I apologize for such a long comment, however I felt it necessary to provide a devil’s advocate that also approaches the issue of raw diets from a skeptical and science-based position, but who has arrived at a different conclusion. My own anecdotal experience has done nothing to convince me that raw diets are harmful. I have never witnessed a broken tooth or salmonella infection, nor any perforated bowels by bone shards. In fact, on the contrary I have helped to pull several commercially available, “safe” products such as rawhide, Greenies and the supposedly indestructible Kong toys out of dog intestines. I feel that the physiological argument for raw provides a plausible basis for further study and that such an argument might yield positive results if ever subjected to a properly controlled and blinded study, but without proper data I will continue to be cautiously optimistic about the potential benefits of a properly-fed raw diet, and won’t dissuade clients who approach me about the possibility of starting a raw diet and will try to steer them toward one of the AAFCO-tested commercially raw diets whenever possible.

  94. TBRech says:

    To the BARF advocates:
    My background as a registered nurse is primarily in public health epidemiology. Recently the trainers in our puppy class advocated the use of raw bison bones as a pacifier for puppies in their crates. It was difficult not to speak out and opine about foodborne illnesses and infection control, but there are better times and places. Choosing the right time to suggest this is a poor choice may or may not come during the course of the class for our two new pups. I hope I will find the right opportunity to interject a scientifically based opinion based on solid principles of infection control and food hygiene.
    Our dogs are fed a healthy diet from a company with certified organic food. We choose to eat organically as much as possible. Why? We like the flavor better and prefer to avoid foods which have been treated with hormones, antibiotics and or pesticides. Does this matter for our pets? It would be wonderful if there were solid research to back our choice. The likelihood of this kind of research being conducted isn’t great. Having this kind of research repeated and peer reviewed in a scientifically base journal would be even more remote.
    My favorite Infectious Disease doc online is Dr. Mark Crislip and as he says “in my experience” is a dangerous phrase. What one experiences does tend to cement our beliefs. What one witnesses is limited. I know from collecting reports and interviewing people that what they perceive as being true when they become ill is often wrong. Doing solid analysis using programs like EpiInfo is critical. The big picture is not seen individually…and it isn’t even seen by individual practitioners.
    JM, I did my share of biomedical (medical and veterinary) surgical illustrations, took comparative anatomy, too when in college, so I have seen a lot of things most pet owners have not. I also did some volunteer work for a wildlife organization using my technical training as a nurse. People must supervise access to any kind of toy, even the Extreme Kong toys. I would never give our dogs rawhide either. I want to know the country of origin for all the ingredients in any substance or toy I give our pets, too. In public health, one key is risk reduction and BARF is not a reasonable low risk diet given the potential for contamination which can affect both pet and human.

  95. TBRech says:

    JM…you mentioned your own anecdotal experiences. Well I will share mine: In investigating a salmonella outbreak a number of years ago, the index case was a dog owner who feed her dog a raw diet.
    I can mention a few other investigations but the point is…while you may not have seen this as a Vet student, public health authorities could well have seen this kind of association. However, my state’s Health Department only looks at reportable cases of diseases for humans with a few notable exceptions and do not count animal cases.
    Perhaps Vet schools collect data on the types, frequency and etiology of communicable diseases and (especially zoonoses) in animals treated in their clinics. If this is true, please advise as I think this would be a fascinating meta-analysis.

  96. Calli Arcale says:

    I concur with JM that dogs are probably best off eating mainly (or even entirely) meat. I’m not sure it logically follows that the meat has to be raw. Given that dogs can and do get foodborne illnesses, I really see no reason not to cook their food. Indeed, when I do give my dogs meat instead of kibble, it is never raw.

    I would also like to specifically address this comment:

    So the level of testing of both ingredients that go into pet food and the foods themselves post-production is extremely questionable to nonexistent.

    This is an interesting statement to make. You seem to be objecting to processed dog food on the basis that the ingredients must not prove themselves safe, individually or conjuction. But this is not a condition peculiar to pet food. It is actually true of human food as well. As long as all of the ingredients fall under the “GRAS” category (and being generally recognized as safe does NOT mean it has never been tested), there is no reason to suspect adulteration, and there are no excessive health claims, the FDA is not going to get involved. It’s not really its job to decide what people or their livestock ought to eat. It’s job is just to enforce some minimum safety standards on the food itself. USDA has more to say on the “what should we eat?” question, so if you want to object, that’s probably what you should be looking at.

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