Repeat After Me: “Dogs are not Wolves”

It should be obvious that there is a difference between acknowledging domestic dogs evolved from wolves (which is a widely accepted theory with strong supporting evidence) and saying that dogs essentially are wolves (which is nonsense). Try to picture a pack of pugs or Bichon Frise brining down and savaging an elk, and the impact of artificial selection ought to be quite clear.

Unfortunately, people all too often misconstrue the ancestry of dogs as a justification for extrapolating from what they know (or think they know) about wolves and applying that knowledge to our canine companions. The infamous “alpha roll,” is an example of this. Attempting to establish a healthy, smoothly functioning relationship with your dog by periodically tackling and pinning him or her to the ground, preferably while growling ferociously, is a ludicrous idea that nevertheless managed to gain some popularity at one time on the basis of the argument (grossly oversimplified) that that is how wolves establish stable dominance relationships.

The most prevalent form of this kind of phylogenic fallacy today are some of the canine dietary fads, including raw meat-based or BARF diets, grain-free diets, and so-called “biologically appropriate” feeding. I’ve written about BARF diets, and the fallacious reasoning behind then, before. And I have written numerous times about raw diets and all the reasons why the have no proven benefits and at least some undeniable risks (for example). While the statement that the dietary needs of dogs may be similar to those of wolves in some ways, based on their phylogenetic relationship, is perfectly reasonable, the claim that one can accurately predict the optimal diet for dogs based on what wolves eat in the wild is simply nonsense. The dietary needs of dogs have been shaped by many factors, not least among them their long association with humans, and they need to be worked out through thorough and rigorous scientific research, not speculation and the appeal to nature fallacy.

An example of the kind of research that we need, which also shows in specific and relevant ways that dogs are not wolves, is a recent study reported in the journal Nature:

Erik Axelsson,Abhirami Ratnakumar,Maja-Louise Arendt, Matthew T. Webster,Michele Perloski,Olof Liberg,Jon M. Arnemo,Kerstin Lindblad-Toh.. The genomic signature of dog domestication reveals adaption t a starch rich diet. Published online January 23, 2013. doi:10.1038/nature11837

The study consisted of a thorough comparison of dog and wolf genomes, identifying a number of differences related to the domestication process. Many of these differences have to do with genes involved in brain development and function, which will hopefully help us to better understand the behavioral differences between dogs and wolves related to domestication. But a significant subset of the genes found to be different between dogs and wolves involve the digestion of starch. Starch was an important energy source for humans at the time of the domestication of the dog, and so dogs adapted to the available food in ways that distinguish them from their more carnivorous ancestors.

Our results show that adaptations that allowed the early ancestors of modern dogs to thrive on a diet rich in starch, relative to the carnivorous diet of wolves, constituted a crucial step in early dog domestication…The results presented here demonstrate a striking case of parallel evolution whereby the benefits of coping with an increasingly starch-rich diet during the agricultural revolution caused similar adaptive responses in dog and human.

This genetic information, and the already well-known anatomic differences between dogs and wolves, make it clear that domestication has dramatically altered the structure and function of the dog body. Extrapolating from the natural diet of wolves to the nutritional needs of dogs is not reasonable nor supported by the data, which instead indicates that dogs are more suited to an omnivorous diet. The current fad that identifies carbohydrates in general, and grains in particular, as inappropriate and harmful for dogs is irrational and contrary to the clear evidence that dogs are well-adapted to such food sources.

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30 Responses to Repeat After Me: “Dogs are not Wolves”

  1. Caro says:

    This is very interesting because I was thinking about changing the alimentation of my dog not a long time ago..A colleague of mine is 100% for raw-feeding and was telling me that I was poisoning my dog with dry food…Well, after reading some of your articles (recommended from one of your French colleague), I don’t want anymore to feed my dog with only meat and bones…BUT…I am still thinking of some fresh equilibrated food…Unfortunetely it looks complicated and I am afraid of doing mistakes impacting the health of my dog (and also to ruin myself but it is another subject!), which would be exactly the opposite of what I want to achieve.. I am not yet decided…Let’s read more articles and get more information! I found a website of a dietitian veterinian selling menus adapted to your animal…AND also food supplements…Somehow strange…

  2. gat says:

    Is this what you were reading?
    http://www.patriciamcconnell.com/theotherendoftheleash/dogs-wolves-diet-and-sociability

    Yes I agree dogs are omivores. And as Dr. Karen Overall likes to say” Omivores with strong carnivore tendencies”. I wonder if that dog, I believe it was a collie in Somerst UK that lived until it was 27 and was a vegetarian, ate organic lentils, rice and veggies is really true?
    I have still not found any research studies on dog diets…Comparitive or otherwise.. Only simple ones done by IAMS type companies. I will keep looking…

  3. gat says:

    The William R. Pritchard Veterinary Medical Teaching Hospital at the University of California, Davis, houses what was the first therapeutic pet nutrition center in America when it opened in 2003. Today the hospital treats more than 25,000 small animals every year, and the nutrition center does much of its work on the clinical frontier where sustenance meets medication. Here, on a wall outside the Nutrition Support Service, I noted a plaque announcing that the center had been backed by money from the Nestlé Purina PetCare Company and Hill’s Pet Nutrition Inc. “There’s virtually no national funding out of the federal government for research on the health and well-being of cats and dogs,” said Bennie Osburn, the dean of the university’s School of Veterinary Medicine. “We have not seen N.I.H. show interest. The U.S.D.A. has not shown interest. The federal government will provide basic funding for ornamental flowers, but not companion animals.”

  4. gat says:

    Here is the artcile in complete form about pet food and funding and research that I thought was intersesting…
    http://www.nytimes.com/2007/09/02/magazine/02pet-t.html?pagewanted=1&_r=0

  5. gat says:

    These scientists were unable to find any valid research on dog diets..

    http://www.nytimes.com/2010/06/01/health/01brod.html“Recognizing the high value most owners place on their companion animals, and distressed by recent recalls of contaminated pet foods, two scientists decided to examine the pet food industry and the evidence for the value of its products and the claims made for them. Marion Nestle, the Paulette Goddard professor of nutrition, food studies and public health at New York University, and Malden C. Nesheim, emeritus professor of nutrition at Cornell University, have packaged their findings in “Feed Your Pet Right: The Authoritative Guide to Feeding Your Dog and Cat,” published in May by Free Press.
    “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.”

    And, indeed, it is primarily human food companies — Nestlé, Purina, Mars and Procter & Gamble — that make the pet foods sold throughout the world. Of course, in much of the world, domestic dogs and cats survive on table and street scraps, not commercially produced pet foods. In seeking evidence for the added value to health and longevity of commercial pet foods, the authors found almost none with any validity.

  6. gat says:

    Do you think this is true or just false information on how cruel IAMS is when they experiment on animals? I know PG is really bad and IAMS is part of PG..but I hope this is just a lie…it would make their findings invalid if this is how they conduct food trials on animals in cages, who are stressed..I know so many dogs that have gotten diagnosed with false Cushings…simply because they were at a Vets office…stressed..

    http://www.iamscruelty.com/

  7. Piet Hein II says:

    Dear PETA troll,
    In reference to your last 5 posts:

    #1) Why would you ask Skeptvet if he was referencing a particular article by quasi-behaviorist Patricia McConnell when, in fact, his post was in reference to a peer-reviewed study by Axelsson, et alia on the genomic evolution of the canine species in reference to nutrition? Might one presume from such a statement that you failed to actually read that which Skeptvet posted?

    What is the significance of your reference to behaviorist Dr. Karen Overall and her alleged comment, “omnivores with strong carnivore tendencies.”? What is one to infer from such a statement? How are a behaviorist’s comments relative to a discussion on nutrition?

    What is the purpose of referencing a fictitious dog of alleged 27 years and then speculating as to what foods it may have consumed? Is there any particular point to such? And, if you’re unsure as to whether or not it was a vegetarian, is it not also possible that it may have been an omnivore? Or carnivore? Or avivore? Or molluscavore? Or vermivore? Can you tell me why any such nutritional predilection would be excluded from your assumption?

    #2) What is the intent of your comment? What are we to infer from your comment? Or, more importantly, what do you think Frederick Kaufman, PhD would think of your plagiarizing his comments? Furthermore, what particular expertise in animal nutrition would an Associate Professor of English and Journalism at College of Staten Island and at CUNY’s Graduate School of Journalism have? Are English professors your main source for information on the nutritional needs of domestic animals? How is it that a professor of English would have greater knowledge on animal nutrition than a studied DVM? Do you think, like yourself, that he “know(s) the texbooks (sic) that are studied by the animal phds” (sic)?

    #3) What about the referenced 5-year-old article do you find “interesting”? And to what poignant aspect of said article are we to react? Or become enlightened? Or shocked?

    Is it this? “…the same nutrition experiments…have led to pioneering advances in animal health care. Because nutritional biochemists have measured almost everything about the canine and feline diets — from energy densities to intestinal transit times — they know what to do when something goes wrong. The latest word in digestibility studies…will help save many sick pets down the road.”

    #4) Why do you state that “These scientists were unable to find any valid research on dog diets…” when, in fact, the author of the article actually states, “In seeking evidence for the added value to health and longevity of commercial pet foods, the authors found almost none with any validity.”?

    What is the purpose of emphasizing the statement, “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.”?

    Are you implying that such items are not of nutritional value? Would an animal on the street or living in your home not partake of such biomass? Are animals offended by “byproducts of human food production”? Are the unconsumed remains of a chicken breast harmful to the canine species? And, if so, in what way? Please explain. Is getting a whole chicken breast essential for the health and longevity of a canine species? What about feline species?

    And why did you not include the author’s completion of the above referenced statement: “Besides, the pet food industry serves an important ecological function by using up food that would otherwise be thrown out,” Dr. Nestle said. Is it bad that we, as a society, not waste food? Would poor people be a better depository for such “byproducts”; and not animals?

    Please cite references for your comment, “Of course, in much of the world, domestic dogs and cats survive on table and street scraps, not commercially produced pet foods.” Oh wait, you didn’t say that at all. Allow me to rephrase the question: why do you repeatedly plagiarize without giving credit and why do you lie?

    5) How is it that you know so many dogs that have “gotten diagnosed” with “false Cushings”? Are you a veterinarian? An English major? What number would you say represents “so many”? Is that a lot? What is “false Cushings”? Is that anything like false hyperadrenocorticism? How is “false Cushings” diagnosed in dogs? What is the treatment for “false Cushings”? Does your dog have “false Cushings”? Is “false Cushings” ever diagnosed outside of a “Vets (sic) office”? And, if so, where? And, what is your point of that story? Are we to be shocked by such information? Or take comfort in such? It such good or bad?

    Inquiring minds want to know.

  8. Rita says:

    gat: a large number of people feed vegetarian or vegan diets to their dogs: http://gentleworld.org/good-nutrition-for-healthy-vegan-dogs/ – I don’t find many studies cited there, most evidence seems anecdotal, but there’s certainly a large population to be studied!

  9. skeptvet says:

    Fresh food can be perfectly healthy, and may even have some advantages over commercial diets if prepared properly. But you are correct it is more complicated than most people think. The best option is to have a consultation with a veterinary nutritionist who can design a feeding plan for your specific pet. I have a couple of links on the site for online consultations, or you can look for a nutritionist at the nearest veterinary school.

  10. Caty says:

    I agree with most of what you say, but the raw diet thing, no. I’ve been feeding raw for seventeen years to dogs and cats and they thrive (I have a 20 year old whippet)… And neither they nor I have ever gotten sick 🙂

  11. Caro says:

    Thank you very much for the answer. I looked at one of the link and even contacted them asking for some similar website in France..And they answered very nicely and recommended a French website 🙂 It was actually the one I already found. I just think it is a little strange to sell menus…and also to sell food supplements…for life…I am doing maybe the mistake to compare with humans: if we eat “properly” fresh and good food, we don’t need food supplements. So it looks to me like a business…But I may be wrong 😉 Good idea with the veterinary school: it will be my next step, thanks!

  12. skeptvet says:

    Well, lots of folks have lived into their 90s while smoking and drink in my. Doesn’t’ prove it’s nit bad for you.

  13. Caty says:

    Thats true. But although anecdotal I’ve noticed a big difference in the health of my pack overall since switching, and I’ve had a substantial number of dogs on both. My vet supports it also.

  14. Anthro says:

    @Caty

    I’ve fed my dogs cheap kibble all of their long lives. Individual anecdotes do not prove anything and what you “notice” is most certainly open to bias.
    ———
    I would like to say that the book “Feed Your Pet Right” by Marion Nestle and Malden Nesheim is an excellent and well-documented book that covers every aspect of pet feeding; what is known and not known from research, recipes for homemade food, and lots of myths debunked by two very engaging and knowledgeable writers. Nestle also has good advice for people at foodpolitics.com

    It is somewhat unfortunate that an earlier comment takes one tiny bit of that book out of context and tries to support a rather enigmatic argument with it. It is also unfortunate that the response to this comment isn’t much better and does little to clarify matters.

  15. Todd Caldecott says:

    Until there are clinical studies comparing outcomes between BARF (or similar) diets and conventional diets, your opinions on the matter are woefully inadequate. Anecdotally, I have seen exceptionally beneficial results of implementing a BARF-type diet. My own collie x is a good example – raised on a BARF diet, we left the country and a friend looked after her, and fed her a vet-recommended kibble. Eighteen months later upon return, the dog was 20 lbs overweight and extremely arthritic. Two months back on the diet however, she lost all the weight and the arthritis literally disappeared. Now at 13 years, she has no arthritis, and compared to any other dog her age that we see at the dog park, she runs circles around them.

  16. skeptvet says:

    And until there are clinical studies comparing outcomes between BARF (or similar) diets and conventional diets, your anecdotes are woefully inadequate.

  17. Victor says:

    The lack of clinical studies comparing raw diets to commercial diets is in itself very suspect. It seems that it would be great marketing for a pet food company to fund such a study, just so it could say with science-backed evidence, that “our food has been proven to extend the life of your dog by ____ years.” And in fact, the pet food manufacturers have money to conduct such research. Why it has not been done, or published if it were done, is only open to speculation. Individual citizens have only anectodal evidence to support their views, so I do not think that such evidence should be lightly dismissed given that major corporations refuse to conduct or publish research on this subject.

  18. suzy says:

    I have been doing a lot of reading on this subject and Victor, I also find it suspect that responses from Veterinary organisations, some vets etc is there is no evidence. Why do we dismiss out of hand the observations of an experienced vet like Tom Lonsdale just because he is confrontational. Surely, a large study, funded by the pet food industry or vet schools/groups could et to the bottom of this once and for all. Please direct me to the evidence that any pet food is better than raw. I am open minded but it seems that those who call for scientific evidence should also provide it. All I am seeing when I search is stifling of debate and ridicule of those who hold differing views.

  19. skeptvet says:

    I think you misunderstand the nature of the scientific process. Current practice may be wrong, but it is always built on a foundation of individual elements that have been demonstrated through research evidence in the past. There is good reason to accept current practice until new evidence is available to show us it needs to be changed. This, of course, happens all the time since science is a continuous process of revision and growth. As evidence accumulates, we make changes to our practices, usually small ones but occasionally major overhauls. The individuals who propose that current practice is wrong or that an alternative practice is better bear the burden of proof to support these claims. The proper response to such new claims is skepticism, which means a withholding of final judgment until compelling evidence is presented.

    In the case of raw diets, claims are often made that they are healthier than current diets. There is no scientific research evidence to show that this is true. And the theories advanced for why it might be true are pretty farfetched. So while no one can say definitively that raw diets are not better than commercial diets (and I certainly have never made that claim), it is appropriate to say that there is currently no compelling reason to believe they are. The claims need not be taken seriously until the people making them have developed the research to show they have merit. It is not necessary or appropriate for the rest of us to 1) accept these claims without evidence or 2) for skeptics to be expected to do the work of proving which kind of diet is better. That job belongs to those who want to promote the new practices.

    There is no stifling of debate. Debate is a conversation among people with different perspectives, and that is exactly what’s happening in veterinary medicine. Those who favor raw diets are telling the public these diets are healthier. Those of us who are unconvinced are telling the public there is not yet any real evidence to say this is true. The resolution to this issue will require raw diet advocates to produce data showing they are right, as is required of any new idea in science, or to eventually accept that they are wrong if the research is done and that’s the outcome. That’s how the process works, and while ridicule is rarely appropriate, there is nothing unhealthy about vigorous, substantive debate. That’s how we grow and learn.

  20. Quintin says:

    Well what I know about wolves and dogs is.. A dog still have about 90% wolf DNA in them. And a wolf is just a wild dog.

  21. skeptvet says:

    Humans share 96% of the same DNA as chimpanzees (http://www.ncbi.nlm.nih.gov/pubmed/12368483). Are we just tame chimps? That is not a very accurate understanding of genetics.

  22. Katy says:

    To be more precise dog and wolf DNA are 99.8% identical.
    Humans and chimpanzees can not interbreed, wolf and dogs can and do produce healthy, fertile offspring. Dogs are merely a subspecies of the gray wolf (Canis lupus).
    So to compare wolves and dogs vs humans and chimpanzees is rather silly.

  23. skeptvet says:

    You missed the point, which is that total homolgy of DNA sequence is not a useful measure of phenotypic similarities. The degree of homology is roughly related to the degree of phylogenetic relatedness, but it cannot be used to make arguments about something like the optimal diet for one species based on the typical diet of another.

    As far as the species definition, ability to breed is one small compnent of that. Technically, ability to interbreed “under natural conditions” is usually part of the definition, which allows polar bears and black bears to be classed as separate species even if they can be bred in captivity. And for what it’s worth, I suspect introducing a pug or teacup Yerkshire terrier to a wolf would not result in successful production of offspring.

    In any case, the point is that claims about optimal diet for dogs based on what wolves are known to eat in the wild are not believable for a number of reasons, including the fact that dogs are phenotypically distinct from wolves in relevant ways.

  24. Kristin says:

    Skeptvet, I was wondering what you would consider to be the optimal diet for a domesticated canine to be, taking into account the most reliable research on the subject. What do you/would you feed your own dogs? I ask this with non-malicious intent. I’m a bioengineering student with veterinary school in my horizon, and nutrition has long been a passion of mine. However, the limited unbiased studies and research behind much of the industry has always been my greatest frustration.

  25. skeptvet says:

    As I’ve said elsewhere, I don’t believe anyone knows what an optimal diet is for any individual dog. We have a good handle on how to avoid gross deficiencies. And we have information of varied quality on specific nutritonal needs for some medical conditions (e.g. renal disease), life stages (large breed puppies), and so on. But there is so much we do not know, it is impossible for anyone to legitimately claim that they know the optimal diet for any given dog, much less for dogs in general.The subject is complex and uncertainty is inevitable, as in all of medicine. We always have to walk the fine line between accepting this uncertainty while still doing the best we can to base our judgments on the best available evidence appraised critically and thoroughly.

    I recommend commercial diets, preferably from the larger established companies that have good quality assurance processes, scientific research staff, and a track record. But I don’t have strong brand preferences, and honestly I think most of the differences touted in advertising between brands are merely that–advertising. Legalized lying at worst, and even at best spin, not education. So I recommend clients monitor signs of general health (energy, body condition, coat condition, stool quality, etc) and consider trying a different food if there is any problem in any of these areas. If there are complicated specific needs (e.g. food allergy and renal disease together, unusual conditions such as cystine bladder stones or Irish Setter gluten intolerance, etc), I recommend a consultation with a board-certified nutritionist. I also recommend this if the owner wishes to feed a homemade diet for idealogical reasons regardless of the medical situation.

    There’s no doubt that much of our information comes from industry, so there is a risk of bias there. Unfortunately, the folks who present unconventional approaches to pet nutrition use this as an excuse to ignore all the information, biased or not, and then base their own recommendations on even less reliable data (anecdotes, theoretical arguments, sloppy research, etc). The fact that we don’t have perfect, complete, unbiased evidence is a problem, but it is not a reasonable solution to ignore this evidence enitrely and replace it with even less reliable speculation.

    I have always fed commercial dry diets of various brands (Nutro, Iams, Hills, Purina). And while I believe anecdotes prove nothing, when people talk about how unhealthy and toxic these are, I point out that my dogs have lived from 14-16 years, which is well beyond the average for large breeds.

    If we take a strictly skeptical, science-based approach to nutriton and to all the evidence, whatever the source, then we are most likely to reach measured, reasonable conclusions. We cannot let the perfect be the enemy of the good or get too carried away by any particular idea beyond the evidence currently available for it.

  26. STG says:

    What an interesting post. I came to this website via doing research on Cushing’s disease which my dog was just diagnosed with. She may also have another underlying neurological issue like a brain tumor? The vet doesn’t know for sure–so this is a real grey area. The vet is trying to provide my dog with the best medical treatment based on his clinical experience and evidence based vet medicine without recommending many tests and procedures which might not change the outcome of my dog’s health. Some people have been really insensitive and have made outrageous comments. One so called friend said that she hoped I didn’t kill my dog with pharmaceuticals. Sadly, some people have become so polarized and ideological about mainstream treatment versus alternative that they have no capacity for empathy and understanding of difficult decisions regarding a pet’s health. Sorry about this off-topic rant. As far as diet goes, I think this article and the research is very interesting. I just try to buy my dog high-quality dog food and supplement with small amounts some real whole food from my plate (a little organic beef, chicken, sockeye salmon and skin). My dog has never been over-weight and I don’t think her current condition can be attributed to dietary causes. I find that some of the alternative vets and alternative physicians can also engage in over-treat or over-diagnose especially recommending a multitude of supplements. I don’t know about dogs, but at least in humans there are researchers that have questioned the wisdom of loading up on antioxidants or vitamins. I think Nick Lane (British biochemist/Evolutionary theorist) is a good source on this topic.

  27. Greg Gilbert says:

    Somewhere in my reading I came across the assertion that dog/coyote crosses while possible were not viable in the wild. This is because of the timing of ovulation. I would guess the thinking is something like this: Dogs come into estrous many times each year while coyotes are timed to come into estrous in late winter. This timing would be, presumably, for maximizing the available food supply for lactation and feeding upon the arrival new pups. If the dog/coyote mix were to breed according to a dog’s schedule there would be insufficient food for the offspring and the breeding would fail.

    This appears to be speculation, but a likely hypothesis, and might apply to the notion that dogs are not wolves.

  28. Pingback: One More Time: Dogs are not Wolves! | The SkeptVet

  29. Ginger says:

    I laughed that you used the Axelsson study as evidence that dogs have somehow evolved in the last 30,000 years. This study was extremely poorly designed. You might not be aware of this, but they fed the dogs in the study a commercial diet high in starch and they fed the wolves a diet that had a much lower and much more appropriate starch content. So I’m afraid the only conclusion one can make from this study is that the dogs were exhibiting enzyme induction as a result of their diet. The wolves would have exhibited the same induction had they properly controlled the study and fed the wolves the same high starch diet. I think you need to go back to the drawing board on this one.

  30. skeptvet says:

    I’m afraid your critique doesn’t make much sense. The study involved genome sequencing and identifying differences in dog and wolf DNA associated with, among other things, production of enzymes for starch digestion. No dietary difference is going to alter the DNA sequence of the individuals or the species studied. One might argue that the function and expression of genes can often be affected by diet, but that isn’t what this study looked at.

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