More Evidence of the Risk of Infectious Diseases Associated with Raw Pet Foods

I try to keep track of new research on the subject of raw food for pets. So far, the research only allows us to conclude:

  1. There is no evidence to support claims that raw diets are healthier than cooked commercial foods.
  2. There is consistent evidence that raw diets are contaminated with potentially harmful bacteria.
  3. It is not yet clear what the likelihood of infections in people or pets from these bacteria.
  4. Raw bones, often included in raw diets, may reduce calculus and periodontal disease risk, though this isn’t clearly demonstrated. However, they also present a real danger of injury, including broken teeth.
  5. Most homemade raw diets, and some commercial raw diets, may have significant nutritional deficiencies.

The latest study adds to point number 2, that such diets are far more likely than cooked pet foods to be contaminated with bacteria that can cause disease in humans and other animals.

Nemser SM, Doran T, Grabenstein M, et al. Investigation of Listeria, Salmonella, and Toxigenic Escherichia coli in Various Pet Foods. Foodborne Pathog Dis. 2014 Sep;11(9):706-9. doi: 10.1089/fpd.2014.1748. Epub 2014 May 13.

Conducted by the FDA Center for Veterinary Medicine, this study looked at over 1000 food samples over a two-year period. The results clearly show that the risk of contamination with disease-causing organisms is much greater for raw commercial foods than for cooked pet diets.

Of the 480 dry and semimoist samples, only 2 tested positive: 1 for Salmonella and 1 for Listeria greyii. However, of the 576 samples analyzed during Phase 2, 66 samples were positive for Listeria (32 of those were Listeria monocytogenes) and 15 samples positive for Salmonella. These pathogens were isolated from raw foods and jerky-type treats…

This study showed that raw pet foods may harbor food safety pathogens, such as Listeria monocytogenes and Salmonella. Consumers should handle these products carefully, being mindful of the potential risks to human and animal health.

While this doesn’t answer many of the other questions about the risks and benefits of raw diets, it strengthens the position that until some tangible benefits are shown through controlled scientific research, not simply armchair theorizing and anecdotes, there is little reason to take the risk of feeding these diets to our pets. If proponents of these diets want to convince the rest of us the risk of disease is worth taking, they have to do more than say, “It makes sense” or “It worked for me.” They will need to produce genuine scientific data to show the benefits they claim are real and greater than the risks.

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54 Responses to More Evidence of the Risk of Infectious Diseases Associated with Raw Pet Foods

  1. Beccy Higman says:

    I’d be interested to see results of similar testing in the UK as our regulatory regeime is different to that in the US eg since the salmonella in eggs scandal there has been routine vaccination against salmonella in all egg-laying flocks. Eggs can’t have the Lion mark (a quality indicator) if they don’t come from a vaccinated flock. There has also been an intense focus on listeria. It would be helpful if more of the results of testing done at abatoirs was routinely published too. Ah well.

  2. Jennifer Robinson says:

    Not surprising. The reality is probably worse than the study findings, as many raw feeders freeze five or 10 pound bags and then feed from them over several days. Great for cultivating bacterial cultures.

    The phrase “potentially harmful” is significant. Is there evidence that dogs and cats are getting sick from the bacteria? Long ago I had a vet tell me that a dog with a healthy, mature immune system could handle salmonella (his point was, don’t feed chicken frames to puppies under 4 mo). Is there evidence that raw feeders are getting sick?

    I fed a mix of dry and raw for several years while running a boarding kennel in Australia (where 10 kg of chicken frames went for $6-$8. An 18 kg bag of Eukanuba cost >$120). Neither I, nor my employees got sick, and sanitation was pretty dubious. I can’t remember any problems with dogs with GI tract infections. The most common complaints we got were (1) my dog gained weight; and (2) my dog didn’t want to eat his food when he got home. I was breeding Labradors, and the raw diet made weight control difficult.

    Yes, this is anecdotal, and it would be good to have a controlled study. But N>1000 dogs and duration of ~4 years offers at least face validity.

    Btw, I no longer feed raw. In the US, dry food is relatively cheap and it is so much easier to control a dog’s diet when you can measure the kibble in a cup. Keeping raw meat around in any quantity is a pain in the backside.

  3. skeptvet says:

    There have been cases of infections in dogs and cats, and in their human companions, with organisms found in raw foods. These are rare, so I don’t think the risk is high, but I don’t see the point in taking it at all unless there is evidence that the diets have some benefit, and so far there is nothing beyond anecdote and speculation to support that. I think controlled studies are not just a nice extra but really a necessity to make informed decisions. Otherwise we’re guessing, and while we often have to do that, we need to be clear about the limits in our knowledge when it is primarily based on anecdote.

  4. I’d be interested in seeing what you consider a reasonable nutritionally complete raw/homemade diet should consist of, based on your research. From what I can gather, many of the most serious flaws that you point out are ones largely based on poor understanding of how to properly/responsibly feed homemade diets. Although I can appreciate that you might not feel your blog is the appropriate outlet for educating people on the specific details of how to feed their dogs, I do not think taking a rigid anti-homemade/raw approach is the answer either.

  5. skeptvet says:

    If you have actually read my articles, you know I do not take “a rigidly anti-homemade/raw approach.” I say over and over again that there may be benefits to both, and that I actually suspect there are benefits to homemade cooked diets. What I object to is claiming these benefits exist without evidence for them, which currently does not exist, and ignoring the risks, which most proponents do. At the moment, there is some evidence for small but real risks and no evidence for benefits, so I don’t see the point in such diets. This is a thoughtful and nuanced position subject to change based on changing evidence, not a rigid or closed-minded position.

    As for what people should feed, I have recommended and reviewed the book Dog Food Logic, which is all about this, so I encourage everyone interested in thinking about what to feed their pets to read this. I think the AAFCO standards pretty clearly prevent obvious deficiency or excess disorders. I think there is good evidence for some dietary therapies aimed at specific health problems (such as special diets for animals with kidney disease). I don’t think a strong, universal generalization about what is best for all dogs, all cats, etc. is possible or reasonable. And I don’t think anyone knows what the optimal diet for any individual pet is because the interaction between nutrition and health is complex.

    So at this point, I feed, and recommend feeding, cooked commercial diets that meet AAFCO standards or homemade diets formulated and supervised by a veterinary nutritionist. I don’t see much reason to prefer one brand over another, and I think most people are unable or unwilling to make the effort needed to feed a homemade diet that is properly constituted. Most homemade diets and diet recipes out there are as haphazard and nutritionally dubious as what people tend to choose for themselves, and we all know that our own nutrition could stand improvement so it is unclear why we would recommend such a haphazard approach for our pets.

  6. Anthro says:

    I would also recommend “Feed Your Pet Right” by Marion Nestle, PhD and Malden Nesheim, PhD. It includes a recipe for nutritionally sound (cooked) homemade pet food. While noting the lack of adequate research, this book presents the relevant science and makes the best conclusions from the available evidence.

    From Amazon:

    Human nutrition expert and author of the critically acclaimed What to Eat, Marion Nestle, Ph.D., M.P.H., has joined forces with Malden C. Nesheim, Ph.D., a Cornell animal nutrition expert, to write Feed Your Pet Right, the first complete, research-based guide to selecting the best, most healthful foods for your cat or dog. A comprehensive and objective look at the science behind pet food, it tells a fascinating story while evaluating the range of products available and examining the booming pet food industry and its marketing practices. Drs. Nestle and Nesheim also present the results of their unique research into this sometimes secretive industry. Through conversations with pet food manufacturers and firsthand observations, they reveal how some companies have refused to answer questions or permit visits. The authors also analyze food products, basic ingredients, sources of ingredients, and the optimal ways to feed companion animals. In this engaging narrative, they explain how ethical considerations affect pet food research and product development, how pet foods are regulated, and how companies influence veterinary training and advice. They conclude with specific recommendations for pet owners, the pet food industry, and regulators. A road map to the most nutritious diets for cats and dogs, Feed Your Pet Right is sure to be a reference classic to which all pet owners will turn for years to come.

  7. Ggt says:

    I recommend Dr. Susan Lauten as a resource on pet nutrition. If you contact her by email, she will answer questions for free:

  8. Jan mason says:

    i just spent several hundred dollars on my Peke who had recently began eating raw frozen food because the ground up raw bones had partially blocked her stomach. She was very sick! No more raw for us!

  9. Art Malernee dvm says:

    . Has hills or antech tried to repeat this raw study?
    Art Malernee Dvm
    Sent from my iPad

  10. L says:

    I wouldn’t feed my dog a diet that caused it to have abnormal lab values.

  11. v.t. says:

    ^ well, Dodds wants reference ranges changed for the raw-fed pets. Thus, no abnormal values, theoretically – holistic practitioners have no qualms modifying whatever they want so they can justify their claims and beliefs.

  12. Art Malernee dvm says:

    I would put my money on a difference because of improper randomization.

  13. L says:

    Well, maybe they should change some of the reference ranges for humans too. As we know, social drinkers tend to have elevated LFTs, lol. Maybe there is nothing wrong with that….

  14. Art Malernee dvm says:

    In 1970 the head of internal medicine at my vet school would tell our class to use raw calf liver to treat anemia because there was something unknown in it that modern science could not provide with its commercial dog food, vitamins and supplements. It’s only one study but is prospective and attempted to be randomized. Vin is talking about the study right now but they are spending a lot of time trashing the author rather than attacking the message. I still think the study will prove to be flawed because most 1st study’s showing an effect are false positive but would love to see this study repeated by Hills or Antech. I will be surprised if raw diet has this big of effect on blood test. A small BUN elevation maybe

  15. v.t. says:

    Why a new study on raw liver, when we have safer, more effective treatment for anemia (depending on cause of course)?

    Hypervitaminosis A, potential for contamination, unethical, pet owners always tend to do “more” than is necessary with raw foods (supplementation, and if recommended to feed liver, they will always feed more or for longer than recommended).

  16. Art Malernee dvm says:

    V.t. , I was trying to make the point that uncooked dog food has been promoted without good evidence in the profession for a long long time. This study
    Is being used to promote raw . Prospective and randomized the study is but it’s just one study that I “believe” independent researchers will not be able to repeat. We have been calling for prospective randomized trials and now we are starting to see them. I want to share prospective randomized studies with others even when I “believe”the study is somehow flawed. Does anyone know if this study was registered before it was started?

  17. v.t. says:

    Thanks, Art, for reiterating.

  18. Adriana says:

    (Not-so) Funny story:
    I’ve always wanted to put my dog on a raw diet, but every time I would bring the subject to my vet he would scare me away with the harmful bacteria risk.
    Fast forward a few years and I end up being transfered to the US – dog and all. So, I land in the US, drop off the dog and run to the nearest pet store – which happened to be a boutique kind of pet shop – to get some dog food. Two days later, my dog is suffering from diarrhea and vomit. It turns out that the dog food had been recalled for salmonella. Just to show that the the risk of salmonella, E. coli or anything else is everywhere, even in OUR food.
    Since that, my dog has been thriving on a raw diet. She is 7 now, her recurrent ear infection is gone, all of her skin problems are gone, all of her itchness is gone. I no longer need to clean her face and fingers every day and she doesn’t drag her butt all over the place to scratch it anymore. Is it anecdotal? Totally. But is my experience, and a positive one.

  19. Debbie Lariscy says:

    I have seen some areas of my dogs health improve after starting a raw diet, consisting of raw chicken, bone and veggies. From a local meat processing plant that now only does raw food for dogs. I see better skin and a big improvement on how much my dog sheds, and he used to shed a LOT. I didn’t start the diet early in my dogs life. I was “sold” on the idea that eating raw meat was what animals have always done and that “our” processed dog food leads to some of the health issues humans have. Specifically, the raw meat is supposed to introduce the enzymes to the stomach that help keep a canines teeth cleaner and healthier. If so, that’s big in my view. Also, no grain or products a canine would not have naturally eaten in the wild, where they began. And many a dry food has been recalled for health issues, so it’s hard for me to single out raw food as being more risky. I am not a professional, but a dog lover and I do want to assure myself I’m doing right by my dogs. Thanks for listening. If you have time, I look forward to your reply. If not, all the best in 2016.

  20. skeptvet says:

    I would encourage you to look at all the other posts I have written about raw diets and consider all the information. Most of the questions and points you raise are common ones, and I’ve tried to respond to them in detail. In brief:

    1. “I have seen”…. Of course, this is the most compelling evidence to most people. Unfortunately, people believe they see improvements in health all the time with therapies that don’t work as well as with those that do, which is why placebos are such an important part of research. As I’ve discussed, half of owners and nearly as many vets report significant improvements in their dogs’ arthritis, for example, when giving them placebos in research studies. So while no one ever seems able to believe it, what we see is not a good guide to what is really happening. We see what we hope and expect to see, things change for reasons other than the ones we are thinking about, and so on. So while this may seem like a good argument for continuing aw diet, bear in mind it’s the same argument other people use to employ homeopathy, pet psychics, and all sorts of other nonsense, so it sometimes doesn’t tell us the truth.

    2. Human processed foods are unhealthy so kibble must be too. The problem here is that commercial pet diets are carefully formulated by nutritionists specifically to be a healthy source of nutrition. Human junk food is formulated to be tasty and appealing, not healthy, and no one even pretends stuff like potato chips and twinkies are good for you. The fact that both come in packages doesn’t make them the same.

    3. No grain/what they ate in the wild. I’ve written extensively about the anatomic and genetic changes in dogs due to domestication. They have been intensively shaped by us for thousands of years, including feeding them our leftovers much of the time, so they simply aren’t wild carnivores any more. A Chihuahua or Pug can’t and shouldn’t hunt and kill its own prey, so that sort of reasoning doesn’t help us choose the best diet. And what most people don’t realize is that in the wild animals eat what is available, not necessarily what is best for them. Malnutrition, starvation, broken teeth leading to infection and death, parasitism, infections, all of these are common in wild carnivores and much rarer in our pets because we feed them better than what they could scrounge on their own in the wild.

    4. Yes, both cooked and raw food can be contaminated with infectious bacteria. However, it is far more common on raw foods, which is why we cooked our own meat. Whether or not there are health benefits to raw that outweigh this extra risk is unknown. I’m not against raw food, but the current best evidence shows slightly more risk and no proven benefit. So feeding it is basically trusting the guesses or personal experiences of others, which is fine but which often turns out to be inaccurate.

    Good luck!

  21. Ariane Holzhauer says:

    I am definitely open to debate and different points of view information regarding raw feeding etc. However, I have some questions/remarks regarding some of the point raised in Skeptvet’s last comment, specifically concerning cats.

    1. “I have seen”/anecdotal evidence – to my knowledge, there is still very little research being done into pet nutrition that is not paid for/sponsored by the pet food industry – if there is, please let me know where to find it. I see that Tuft’s have put out quite conservative statements regarding raw foods (in line with yours regarding risk of bacteria, incomplete formulation etc.) – but they don’t seem to cover commercially produced frozen foods like Rad Cat (frozen raw), of which each batch is tested for salmonella.
    Therefore most evidence is indeed anecdotal, but seeing improvement in one’s cats’ behavior, symptoms, appearance, etc. when feeding raw food in comparison with kibble, seems a good argument in favor for me.

    2. I would venture a pretty safe guess that not all kibble is created equal. You cannot compare the quality of a grocery-story bulk cat kibble entirely consisting of corn, soy, and chicken meal, with a higher quality kibble with meat and low carbs.
    I think we shouldn’t kid ourselves that pet food companies are creating kibble out of the kindness of their hearts – obviously they have need to run a profitable business for their shareholders. With that comes producing food that is attractive to the owners to buy, either by responding to their desire for low price, acceptance by the pet, and/or perceived nutritional quality.
    In addition, your point about does nothing to reflect on the low moisture content of kibble which is not in line with cats’ biological need for moisture in their food. I am definitely much more inclined towards the wet (canned and/or raw) food route because of the latter.

    3. Cats have not evolved the same way as dogs. They have not been domesticated for nearly as long, they have been kept around for a much longer part of their domestication for their innate rodent-hunting capabilities (and therefore kept their obligate carnivore digestive system), etc. The no-grain/low carb argument for cats seems to me therefore much more pressing than for dogs.

    4. Dry foods can also be contaminated, what with kibble being kept at room temperature, fats going rancid, mycological and bacterial overgrowth, etc. Kibble is being handled so much more carelessly than other pet foods (as a pet sitter I see it sitting out in bowls for days) and I’d like to see some more research in that arena as well.

    What are your thoughts?

  22. skeptvet says:

    Good questions. Here are some thoughts in response.

    1. As far as funding bias, this is definitely an issue, but of course it is a problem for almost all the research done in veterinary medicine. And ideological bias is present in every study since investigators always have an expectation of how the research is going to turn out. We can’t simply ignore research if there is any financial interest associated with it or we will have no data on anything. The appropriate thing to do is look closely at the methodology that is used to try and control bias. A well-controlled study (good randomization and blinding, pre-published and objective outcome measures, etc.) is a pretty low risk of bias regardless of who is paying for it. So at this point, the evidence is imperfect but much better for the health and nutritional value of commercial cooked diets than for raw diets. Makes of raw diets and others interested in them need to conduct the appropriate research to demonstrate their claims. Anecdotes are nearly useless except as a generator of hypotheses or when we have nothing else, so ignoring industry research in favor of anecdote isn’t a reliable way to figure out the truth.

    As for the bacterial contamination issue, this does occur with both raw and cooked diets. It is clearly a much higher risk with raw meat, which is demonstrated by robust data on human food safety. No direct comparison between cooked and raw commercial diets, much less between cooked commercial and homemade raw diets, has been done to my knowledge, but the fact that the overwhelming majority of dogs and cats are fed cooked commercial diets and yet there are nearly as many reports of contamination in raw diets as in cooked ones makes it quite likely that these diets do present a much higher risk of bacterial contamination.

    2. The problem is that claims about the superiority of one diet over another are made up, pure marketing. The things you cite, for example, as characteristics of poor diets (lower cost or grocery store distribution, presence of corn or soy, etc) are not really markers of the nutritional adequacy of the diets. These are just claims that opponents of commercial diest keep making without evidence until they begin to be accepted as true. And pet food companies contribute to the problem by catering to irrational fears or desires on the part of consumers. If a food is marketed as “no by-products” or “no GMO,” that is pure marketing, and there is no evidence at all to suggest that diet is any better for your cat than any other. So while it is very likely that some diets are better than others, reading the label and the marketing on the package isn’t a useful well to judge quality.

    I would consider reading the book Dog Food Logic (which uses dog food as the example but applies equally well to the feline side of the pet food market). It delves into how to evaluate a diet as a consumer in detail and is a great resource for informed decision making.

    As for the moisture content, I agree, and I recommend canned diets as both higher in moisture and lower in carbohydrates than dry diets for cats. But be careful, because a lot of “low-carb” cat foods turn out to be very high in fat, and these actually lead to weight can and increase the risk of diabetes and other obesity-associated diseases. Nutrition is never simple, and “low-carb” can be just another empty marketing phrase if you aren’t careful.

    3. Yes, cats are much more obligate carnivores than dogs. They do appear to need higher-protein diets, and there is some evidence that lower-carbohydrate diets are beneficial in some situations, if you bear in mind the issue I mentioned above about fat content and weight. however, there is also plenty of research suggesting some plant ingredients used in cat foods are perfectly bioavailable and appropriate. Remember, in the wild animals eat what they can get, not some imaginary perfect diet. Malnutrition and starvation are common in wild carnivores, so “natural” doesn’t mean “optimal.” There are good reasons we don’t feed live prey to our cats (injury, infectious disease, parasitic disease, etc.), so we have to be sensible and rely on evidence not just theory in figuring out what is the best diet for our domestic cats. Ultimately, comparison studies feeding different diets are what is needed, and while those are difficult and expensive, unless we have them we are mostly guessing. Guessing is fine, but it means we have to avoid being strident about the “right” or “wrong” diets when there is so much we don’t know.

  23. S.G. says:

    Vets are constantly falling back on the idea that there’s just no evidence that raw is better. This reasoning actually seems bizarre to me. Seems to me that the onus should fall on pet food companies to *specifically* prove that their processed food is superior to raw food–in other words, not just testing their own, but pitting theirs against nature’s and testing the long-term health outcomes of both.

    If scientists made a nutritionally complete cereal bar for humans, they would have to prove benefits far beyond “scientifically formulated,” “nutritionally complete,” and “lower risk of bacteria.” They would have to prove that their human kibble is absolutely better than fresh produce and natural human foods. If they went around saying, “There’s just no evidence that fresh tomatoes are better,” and all the doctors parroted that information, I hope humans wouldn’t say, “Oh ok, better safe than sorry.” I hope we’d say: PROVE to us that yours is better than what we’ve been eating so far.

    Then there’s the specific disregard of anecdotal evidence–when people are springing up everywhere to say that their dog/cat specifically had problems on all sorts of fancy kibble, and then those problems specifically went away after switching to raw, people everywhere who love animals should be listening. I am so annoyed with vets who become invested in repeating and defending a status quo instead of perking up and investigating where day-to-day evidence leads them.

  24. skeptvet says:

    It is always up to those who make a claim to provide the evidence to support it. If I say that dogs on commercial diets live longer than dogs on raw diets, it’s up to me to support that claim with evidence. And if you say dogs eating raw diets are healthier than dogs eating commercial diets, it’s up to you to support that claim. That’s a basic principle for how science, and rational argument, work.

    You are also making the false assumption that raw should be assumed to be better because it is “natural” or in some way the automatic default. But that’s not true. Dogs have been eating cooked human food for ten thousand years, and they have been eating commercial diets for decades. Raw feeding is a relatively recent fad, and despite the use of the naturalistic fallacy, there is nothing “natural” about it. Commercial diets are formulated based on research evidence about the nutritional needs of dogs. Raw diets are formulated on the basis of untested beliefs about what is “natural” or normal for dogs to eat. SO the burden of proof is, as always, on those making the claim to have found something better than what the current evidence has supported up to now.

  25. S.G. says:

    Then treat it like the huge gray area it is. No pet food company (kibble or raw) should ever be purporting that theirs is the optimal way to feed an animal, yet vets stand behind kibble companies when all they have is information from the kibble companies… on kibble.

    Then you casually dismiss anecdotal evidence that points in a totally different direction, and demand that laypeople back up what they notice with hard science? Real scientists go, with an open mind, where the evidence leads and consider all possibilities rather than standing back with crossed arms saying, “Prove it.” We don’t need skeptics deterring advancement. The best science comes from fearless, open-minded innovators who are keenly interested in the truth, the whole truth and nothing but.

    The thing is, on an individual level, we don’t need to prove it. It’s happening the other way around in homes all over: An appropriate diet, and the benefits that come with it, are proving it to us. Make these discoveries in your own home, in your own animals, and you’ll see it’s not about “some recent fad and naturalistic fallacy,” it’s about results that pet owners see in their companions. Many of us cannot, in good conscience, go back once we see it with our own eyes.

    The institution of science, by nature, moves slowly. The AVMA and its financial partners are sitting pretty. They have no reason to come around to the leading edge to where all this anecdotal evidence is clearly pointing. I find it disingenuous to hear vets and companies hiding behind the phrase, “It’s up to you to provide the evidence.” How exactly is that supposed to happen? Should I get a study going? Should my butcher? Maybe the companies with the money and the supposed great interest in animal health should take some of their billions and do it instead of saying, “It’s not our job.” Until it’s ALL examined, vets should tone down their confidence level in what they recommend their patients eat.

    And cats are hunters. They eat animals without cooking them. To say “raw is a fad” is a way to assign a value judgment to something that actually needs no defense or explanation. (I don’t know about for dogs–I love them, but I don’t have any.)

    Also, it really concerns me when any vet or pet food company would say that kibble is appropriate for a cat, when they are designed to get the majority of their water from their diet. Your average cat is not going to appropriately make up for that deficit when it has to go out of its way to do something that is not natural to it (i.e. make up the majority of its water by physically drinking water from bowls or fountains). That alone is cause for concern and a good reason to distrust the status quo.

  26. skeptvet says:

    No pet food company (kibble or raw) should ever be purporting that theirs is the optimal way to feed an animal,

    No one knows what an “optimal” diet is, and nobody should make such a claim. I certainly don’t. However, if these companies claim these foods are nutritionally adequate, generally supportive of good health, and beneficial for specific medical conditions when there is evidence to back that up (as in the case of renal diets), then these are perfectly fair claims. They are, as I’ve already mentioned, backed up by more evidence than the claims against commercial diets or for raw foods made by proponents of raw feeding.

    Then you casually dismiss anecdotal evidence that points in a totally different direction, and demand that laypeople back up what they notice with hard science?

    There is nothing casual about my dismissal of anecdotal evidence. There is an abundance of proof, from medical history, cognitive science research, and medical research, that anecdotes are unreliable. Not understanding this is one of the great flaws in most arguments made for alternative medicine, including raw diets. Here are a few more detailed discussions about why rejecting anecdotal evidence is not only not a sign of being closed-minded, it is absolutely necessary to allow us to figure out what is truly best for our pets.

    Why We’re Often Wrong
    Testimonials Lie
    The Role of Anecdotes in Science-Based Medicine
    Why We Need Science: “I saw it with my own eyes” Is Not Enough
    Don’t Believe your Eyes (or Your Brain)

    We don’t need skeptics deterring advancement. The best science comes from fearless, open-minded innovators who are keenly interested in the truth, the whole truth and nothing but.

    What we don’t need is faith-based medicine where personal experience and belief is held to be more reliable than science. The best science comes from those who are willing to admit that things are not always as they first appear and they controlled research, replication, and the rigorous scrutiny of all ideas by a community leads to the truth more reliably than just trying stuff out for yourself and imaging this proves something. Your faith in “see for yourself” is what really impedes the advancement of knowledge and truly effective medicine.

    Complaining about “who’s going to fund the research” and then dismissing any actual research that disagrees with you because it’s paid for by people you don’t trust doesn’t make research evidence for your beliefs any less necessary. You don’t get to simply declare yourself right without evidence because getting evidence requires effort, scientific expertise, and funding. There is plenty of money being made by providers of commercial raw diets, by alternative vets promoting these diets, to fund research if they didn’t believe, as you have already suggested you believe, that such research isn’t really necessary anyway because anecdote is sufficient. And there are non-profit foundations, universities, and other non-commercial organizations that fund veterinary medical research. The lack of evidence is a choice, not something forced on you by circumstances, evil corporations, or skeptics.

    And cats are hunters. They eat animals without cooking them.

    Sure they do. And in the wild, where they do this, they suffer from parasites and infectious diseases (every heard of “songbird fever”), and they don’t live nearly as long as cats fed by humans. It is a fallacy that “natural” means “healthy” or “optimal.” A natural diet is simply what an animal in the wild can manage to get, not the perfect diet for them. Being a carnivore affects a cat’s nutritional requirements, certainly, but that isn’t the same thing as saying that we should feed them exactly what they normally would catch for themselves.

    You are welcome to distrust and question the status quo., That is a good thing. What you aren’t entitled to do, and what does more harm than good, is simply making up an alternative that makes sense to you personally and then declaring it superior to the status quo based on your own beliefs and uncontrolled anecdotal observations. Every failed idea, from bloodletting to homeopathy, has been defended this way, and it simply isn’t reliable.

  27. S.G. says:

    Do I get to declare myself right and superior? No. But I get to declare my pets have a clean bill of health now and the only difference was their diet. It is so much more convenient to feed kibble. And cheaper. My vested interest is in the outcomes I observe in my own home and at vet check-ups. I, as an individual, do not need the research and strictly controlled studies to make a choice for my individual cats.

    Faith-based medicine? I’m talking about a way to feed pets that is bringing pets good results and has yet to be properly studied. Calling it faith-based medicine is not a neutral stance. Can you see your own bias? You admit that there is not enough evidence, but you have clearly taken your stance despite this. To me, a neutral stance of one who wants to know the truth (no matter what it is) takes everything into consideration and says, “Hmm, perhaps.” A closed mind says, “You haven’t reliably proven it to me, therefore get out of here with your faith-based medicine.” This is probably so normal to you that you see nothing wrong with your attitude.

    There is a truly unfortunate arrogance and dismissive attitude in many professionals. And are you truly suggesting that holistic/alternative vets funds these studies? Give me a break. All vets who truly care should be saying, “AVMA! End the controversy. Get us some solid information on all sides.” Until we have more information, refrain from comparing a particular diet to bloodletting and faith-based medicine.

  28. S.G. says:

    And another thing to distrust–companies putting corn and grains into food that is to be feeding obligate carnivores? It is such nonsense, and it hurts our cats. But people who are mindful of choosing grain-free are seen as unthinking, uneducated, unscientific people succumbing to fad diets? I hope everyone starts to think critically about these things so we can move in the right direction, not defend something that can clearly be improved.

    I realize this is YOUR blog, so I must commend you on the uncensored discussions you allow to happen here.

  29. skeptvet says:

    I get to declare my pets have a clean bill of health

    And so do mine, and most of the thousands of others on commercial food. Dueling anecdotes don’t get us anywhere.

    Calling it faith-based medicine is not a neutral stance

    The phrase “faith-based medicine” is not a critique of the evidence or merist of raw feeding, it is a critique of the way you and others argue for raw feeding using anecdotes and personal belief and dismissing or ignoring science. I have stated many times that my position on raw diets is that they have small risks an as yet no proven benefits. Sounds like exactly the neutral stance you are describing. However, when you claim that, in fact, raw diets are better than commercial diets based on your own experience with your pets and the naturalistic fallacy, and then you claim scientific evidence is not needed, is irrelevant if paid for by anyone you disagree with, and is impossible to obtain, then you are taking a faith-based approach to the issue, and that is what I am criticizing here.

    All vets who truly care should be saying, “AVMA! End the controversy. Get us some solid information on all sides.”

    Wrong for several reasons. The AVMA is a lobbying group, and as such it doesn’t set standards for vet med or do research to settle controversies. The burden of proof, whether you are willing to accept it or not, is on those making the claims. It is not my job to disprove your beliefs and to support or at least not oppose the practices you recommend until I have generated the evidence to show you’re wrong. My responsibility as a vet is to weigh the arguments and evidence for all the options and make provisional judgements based on that evidence. Right now, there isn’t good scientific evidence to support the claim raw is better than commercial, so as I’ve said a dozen times, I am neutral on the claim. However, the purported evidence used to defend this claim is generally poor, and I am pointing that out so that animal owners can make truly informed decisions about these claims.

    There is nothing arrogant about not taking your word for your claims about raw foods, about expecting you to provide the evidence to prove these, or about pointing it out when the evidence you use isn’t reliable. You mistake polite, substantive disagreement for arrogance or closed-mindedness. It is, however, somewhat arrogant to believe that your experiences are probative or that your claims should be exempt from criticism, as you seem to be doing in this discussion.

  30. skeptvet says:

    But people who are mindful of choosing grain-free are seen as unthinking, uneducated, unscientific people succumbing to fad diets?

    Again, you are mistaking criticism of ideas and methods for criticism of people. I have never called people who choose grain-free diets unthinking, uneducated, or unscientific. I have, however, pointed out that the theory behind such diets is plausible but unproven, that there is evidence that even obligate carnivores can get valuable nutrition from carbohydrates of grain and other origin, and that many of the claims made in defense of such diets are false, unproven, or unscientific. The focus should ideally always be on the ideas and the evidence, not the individuals.

    And since the purpose of this blog is to provide pet owners with access to ideas, arguments, and evidence they often don’t get to see (most of the information available about alt med generally is produced by people promoting or selling it), it wouldn’t make much sense not to allow or respond to reasonable disagreement. I don’t allow personalized abuse, name-calling, blatant commercial content, and so on here, but civil disagreement is productive and certainly welcome.

  31. v.t. says:


    Had you bothered to notice, skeptvet has 42 articles here on nutrition, you might want to read them, and pay particular attention to the resources he has provided.

    Might also want to read more of his articles, if for anything else, to discover just how “close-minded” he really is. I mean seriously, opponents who come on her screaming foul have no idea what the term “close-minded” means or implies. If you continue reading here, you’ll find skeptvet’s complete acceptance of any plausible idea as long as it has sufficient evidence to back it up. He’s not alone in that requisite, and how you could expect anyone in the veterinary community to practice anything less is beyond me.

    Big Alternative has the means and the money to fund research, they’re pulling in millions every year, perhaps you should be asking THEM why they aren’t proving all their claims and putting forth some evidence. Don’t you think they should be under the same scrutiny and regulation as everyone else in medical science? If you think they shouldn’t be, …. why?

  32. Debra says:

    Okay, I am late in this discussion as I just found it. I would like to ask your opinion on Dr. Pottenger’s Cat study, which was a controlled 10 year study. Yes, it was conducted a long time ago and some consider out-dated, but his findings were an eye opener for me. He had two groups of cats, one fed cooked and the other raw scraps of meat. The group that were fed raw meats actually thrived more, Each generation grew up to be of uniform size and development with normal fur, tissues, and skeletal structure. Calcium and phosphorous levels in their bones were normal. Their organs and nervous system functioned normally and their coordination was perfect. They were very resistant to infections. Their mental state was stable and friendly and you could play with them. There were no birth complications and nursing was normal. The cats gave birth to an average of five kittens each one weighing roughly 4.2 ounces.
    Whereas the cats that were fed cooked meat experienced increasingly poor eyesight – nearsightedness or farsightedness, heart problems, thyroid and bladder problems, nervous system problems, meningitis and paralysis, infections of various organs, ovary and testis problems, liver problems, inflammations, uterine congestion, atrophy of various organs. Increasingly abnormal mental states. With each new generation, the cats became more unpredictable, were more irritable, were biting and scratching more, were less playful, and so on. The males became docile experiencing a drop in libido and sexual interest while the females became very aggressive. The females aborted about 25% of offspring in the first generation, 70% in the second generation and the kittens weighed about 0.67 ounces less than the ones that were fed a raw diet. I understand that the need in for taurine in a cats diet hadn’t been discovered until much later, but I believe that there is still some merit in his study.

    While I understand the concern for Salmonella, listeria, etc. I believe that with proper handling and storage of food there is minimal risk to feeding a raw diet. I do make sure that they also receive the necessary amounts of taurine and vitamins daily. I will not purchase commercial raw food because there are too many unknowns on how it was processed, handled, or who the actual meat sources are. But I have noticed that there have been several recalls on commercial cooked cat and dog foods, to include kibble. It is also my understanding that there has only been 1 case of salmonella poisoning in a cat that was fed a raw diet, and there are many unknown factors in this case. Such as, did the owner prepare the food correctly, how long did they leave the food out before feeding it to the cat, how long did they leave it in the cat dish, was the cat in good health before being fed the raw food, etc.

    All I want is to give my cats a loving home and keep them healthy. But there are so many conflicting opinions out there it is hard to distinguish who is right and who is wrong. All I can do is base my opinion on my experiences. Since feeding raw to my cats their fur is much softer, they are more energetic, therefore more playful, their stools do not stink and are not as frequent as before, and in overall better health. You say this could be a placebo effect, but I disagree. I have spent well over $6,000 in health care for my fur babies before raw and they are much better since I took them off commercial canned cat food. I am talking high quality expensive cat food. And that is not to say that I have not followed up with my vet afterwards because I have and they have found nothing of concern and their medical problems have gone away. I insisted that they run another set of x-rays, ultrasound, and barium studies because I wanted to make sure that my male cat was indeed recovered. He has a clean bill of health, so I am sold on raw. Sorry for the long post.

  33. skeptvet says:

    The Pottenger study, unfortunately, lacked most of the controls one would expect in a nutritional study today: health histories and thorough evaluations of subjects, randomization and blinding, statistical analyses, and many others. Most crucially, as you point out, the likely cause for the differences he saw was the absence of the amino acid taurine in the deficient diets. This has been understood as an essential nutrient for cats for decades, and the diseases associated with taurine deficiency (primarily cardiomyopathy) have disappeared since the practice of supplementing commercial diets with taurine was implemented. So the Pottenger study is really not relevant any more to the issue of whether or not raw diets have health benefits for cats.

    This means that until there is some research with appropriate methods, everyone is just guessing. I understand the logic behind the argument for raw diets in cats, but that only gets us to a reasonable hypothesis, not a reliable conclusion. And I understand the impulse to rely on personal experience. In the absence of good controlled data, this is appropriate. however, I always have to point out that similar personal experiences has “proven” the benefits of every medical therapy ever tried, including bloodletting, homeopathy, faith healing, and lots of others we know don’t work. So such experiences are far less trustworthy than they seem.

    Good luck with your kitties!

  34. Pingback: Pet Fooled. Great documentary for all pet owners - Forums - Yorkshire Terrier Community

  35. J says:

    So you buy all of the meat you consume pre cooked?

  36. skeptvet says:

    No, I cook it before I eat it and wash my hands, countertops, and utensils appropriately. Your point?

  37. Cathy Whitney says:

    I am not a scientist, and cannot make a science based statement here, I am just a dog owner who loves their dogs as family. I work with a holistic/Chinese medicine vet. She started her career as a allopathic vet, as all vets do. She wanted more, and started additional training towards eastern medicine. It DOES NOT replace tradional medicine, it is complimentary. I have been feeding raw, that I make myself, using organic meat that comes from the grocery store. I also add organic vegetables that I either grow or purchase. There are many supplements added to this…My dogs diet is under the guidance of my vet . I see, myself, with my own 2 eyes the health benefits. Here is a prime example: last year we adopted a 71/2 year old JRT. She was fostered by a rescue for 6 months and fed a grain free dry dog food. When I got her, her belly was completely raw and red from her chewing on it. Her ears were infected, and her vaginal area cobbled and swollen, all of this was most likely from many years of self mulilation. I placed her on my homemade raw diet the moment she got home with me. Within 2 weeks, the belly was calming down. Here we are, a year and a couple of months later. She is almost completely cured. No steroids! All done with food. I took her 2 months ago to my allopathic vet for a dental, and had a full blood panel done. Guess what? Came back perfect. i agree that just throwing together a bunch of raw meat and throwing to any pet would not be healthy. But feeding a thought out, balanced diet, homemade, raw or cooked, under the guidance of a vet, has to be better than a bowl of who knows what dry stuff from a bag. We as humans don’t eat that way, why should our pets? As a side note, I have been feeding this way for 16 years. My dogs have never been sick from salmonella, botulism, or any food related illness, and neither have we, and I feed green tripe(which is disgusting, but the dogs love it)

  38. Paul says:

    Cathy, you probably won’t come back to read this but anyway. I have nothing for or against raw food. I do one a pet store. I am going for my MS in Animal Nutrition. I do have two dogs. Now here is where anecdotal evidence flags and fails. Ready?

    My dogs did horribly on a raw diet. On the raw their digestive system was all fouled up, they had atopic dermatitis, my one’s ears were horrible and itchy, etc etc.

    They thrive on there kibble and wet food and cooked meat. The dermatitis is gone, they digest close to 90% of their intake and my hounds ears are far better.

    So there I canceled out our story with my story. That’s why we use studies and we try to repeat the outcomes and figure out what is going on. So far no well designed feeding trials or studies show that raw is superior to cooked. Though there is tons of data showing that the digestibility of cooked food is higher than raw depending on the source. I can go on.

    I sell tons of raw food at my store. And some dogs do well on it, some don’t. I also reserve the right to tell people I’m not going to sell them raw because it is more dangerous if not handled properly. And I know which customers won’t do that. I have nothing against it. As long as it is complete and balanced per AAFCO or even NRC requirements.

    I’m glad you are at least consulting with your vet in terms of nutrition for your homemade diet. Most people don’t and that bugs me to no end.

    Now let’s discuss this all eastern medicine thing. Can we convince you to stop that? It is complimentary to anything because it doesn’t work. It would be akin to say that I do blood letting to balance my 4 humours as complimentary medicine or that I rub mud and dirt and dung into my open cuts because its been practiced for thousands of years to treat wounds in battle.

  39. Cathy Whitney says:

    Hi Paul, I agree with you. Homemade food/raw is not the end all for all dogs or cats. Some cannot do well on it, and if I might ask, was the diet you put your dogs on, a pre made from the store diet, or one you made under the guidance of a veterinarian?
    Our newly adopted senior JRT came out of the bagged crap diet and into a well thought out, vet recommended, moisture rich diet and not only is thriving, but healing from her past life. I have 2 other dogs on the same diet, but I bet they would do fine on any food they eat, including a high end dry dog food. Our JRT is different than them. We had another JRT that we had to put to sleep at the age of 15. She is why I started with this diet. She chewed her paws bloody, and on the advice and guidance of a vet(this was NOT a holistic vet)we worked out the raw diet. It worked for her, along with(OMG NO!)a Chinese herbal supplement. Her skins issues remained clear until she died. What I do is not for the faint of heart, it is expensive and time consuming. I do not recommend it for everyone. But I will never go back to packaged dry dog food. Every time I see a recall, it makes me sad for those pets that may have suffered from the food. I will not give up on holistic vets..they are what has saved my 2 JRTS from the life of steroids/antibiotics circle. When my dogs have needed antibiotics for something, they get it, I’m not against it. But their answer for itchy skin goes straight to steroids. There are other answers, and what I do,is one of them, and is natural. When/or if they have a broken leg, they go to an allopathic vet to get fixed, the same for spay/neuter, dental, and lots of other things. So, again, holistic medicine is complimentary medicine for my dogs, not always the final answer.

  40. v.t. says:

    Every time I see a recall, it makes me sad for those pets that may have suffered from the food.

    You do realize I hope, that many packaged/frozen “raw food” pet diets have also been recalled, don’t you?

  41. art malernee dvm says:

    >>>”allopathic vet”
    As a heads up if you practice EBM I think most would find the term allopathic is offensive. If you have not opened a EBM medical book in the last 25 years a vet or md might be ok with the word used to describe their practice.

  42. Cathy Whitney says:

    I had no idea allopathic was offensive..I apologize! @vt..I don’t buy any dog food..frozen,canned,dried or otherwise. I make it myself from organic meat from Costco, and other sources. It is sold for us humans, I don’t trust any manufactures…and yes, I know of recalls for raw pet diets, and treats etc…
    I am very careful what I feed my dogs, and my family as well. I have never purchased ground meat for my family. I grind my own for hamburger, and I make my own sausage. It’s all about Knowing what’s in our food. The same goes for my dogs. No surprises, nothing from China, no odd perservatives or euthanasia drugs or etc….

  43. Cathy Whitney says:
    Here is another reason I will never buy -remade/manufactured dog food!

  44. Cate says:

    The Clean Label Project refuses to disclose the data they use to rate these foods or the funding for their “studies”. The lab they use seems to have been formed right around the same time as their group as well, I can’t recall everything that was dug up on them but there were a lot of shady connections between funding, testing, and the non profit.

  45. Cate says:

    This was a Q and A they had on Reddit, they were not able to explain how they reached their ratings or why they weren’t releasing raw data and different commenters bring up issues about the labs. If they can’t even stand up to basic scrutiny on Reddit I don’t really see how they intend to defend themselves to actual scientists

  46. Brian Cullen says:

    I am having trouble understanding what you say about all kibbles being equal , looking a a site like which ranks food by the contents , surely a 1 star kibble cant be as nutritious as a 5 star kibble ?

  47. skeptvet says:

    I wouldn’t say that all kibbles are the same, only that we don’t have any objective scientific evidence to allow us to say one is better than another. Sites like the one you reference make up rating systems based on criteria that are not validated or scientific. Ingredient lists are not a reliable guide to the nutritional adequacy or health effects of a food, and labels like “natural” and “grain-free” are meaningless. If you are interested in learnign more about how to evaluate dog foods, and why such ratings systems aren’t useful, I would suggest the book Dog Food Logic.

  48. Brian Cullen says:

    I will be ordering the book as soon as I reply here and look forward to reading it . I have found myself in a seemingly one man crusade to put the brakes on the raw feeding frenzy , I usually start by saying I dont have many issues with raw per se but that there is no evidence of it being better that quality kibble , so this puts the brakes on me it seems on that front , I am buying one of the 5* kibbles for my dogs and now wonder if its a waste of money .
    On a separate note I just want to say I am really enjoying the site and I am learning lots which is always good , last thing …. is there a way to put a search feature on the page as I keep forgetting what I read where and it would make things much easier to navigate , again great site and thanks for the reply .

  49. L says:

    There is a search engine on the right side of the page, just on top of “recent comments”
    If that is not what you mean, ignore me.

  50. Brian Cullen says:

    Opps so there is , cheers L .

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