What do Veterinarians Know About Nutrition?

It is not unusual for people promoting unconventional, approaches to pet nutrition, such as raw diets, grain free foods, homemade diets, a preference for organic ingredients, and so on, to dismiss objections to these approaches made by veterinarians. These people will often claim that veterinarians know little about nutrition and that what they do know is mostly propaganda fed to them by commercial pet food manufacturers. Like most bad arguments, this one contains a few bits of truth mixed in with lots of unproven assumptions and fallacies.

Most veterinarians do have at least a semester course on nutrition in general. And a lot more information on the subject is scattered throughout other courses in vet school. So the idea that we know nothing about the subject is simply ridiculous. However, it is fair to acknowledge that most veterinarians are not “experts” in nutrition, if by this one means they have extensive specialized training in the subject. The real “experts” in this area are board-certified veterinary nutritionists, individuals who have advanced residency training in nutrition and have passed the board certification exam of the American College of Veterinary Nutrition.

Of course, as I always take great care to point out, expertise is no guarantee of never falling into error, particularly expertise based primarily on experience and a familiarity with the opinions of other experts rather than solid scientific research. Given the limited research data available on many important questions in small animal nutrition, even the real experts are often forced to rely on extrapolation from basic science or research in humans and their own clinical experience, which are important sources of information but always less reliable than studies specifically designed to answer these questions. Nevertheless, boarded nutritionists have a legitimate claim to expert status in this area. And as a group, they generally are skeptical of many of the alternative approaches to nutrition, as they should be give the paucity of data to support them As for the question of the role of the pet food industry in veterinary nutrition education, there is some truth to the claim that much of that education is sponsored by companies who make pet foods. Obviously, most veterinary nutritionists put their training to work researching and evaluating food for veterinary species, so the money and expertise in this area tends to concentrate in industry. And it is not entirely unreasonable to ask the question whether or not this influences the information veterinarians get about nutrition. It quite likely does.

This is not the same thing as saying that veterinarians are all lackeys or dupes of industry and unable to think critically for themselves, however. I am generally as skeptical and critical of pharmaceutical companies and mainstream pet food companies as I am of herb and supplement manufacturers and producers of alternative diets. All of them have both a genuine belief (most of the time) in their products, a genuine interest in the welfare of the animals they serve, and a high risk of bias and cognitive dissonance that impedes their ability to see and accept the flaws in their own reasoning or the data that contradicts their beliefs.

One should always be aware of bias, but that awareness does not justify ignoring the arguments or evidence coming from a source with potential bias, only evaluating it carefully and critically. The reason science is so much more successful than unaided reasoning is precisely because it is a method for compensating for human biases and other cognitive limitations that interfere with our seeing the truth. Mainstream pet food companies undoubtedly have biases, but often they also have good scientific data, which is rarely available for the alternative products and approaches. Ignoring this data in favor of opinion, theory, or personal experience is not a recipe for improving the state of veterinary nutrition.

The real issue is not so much what do general practice veterinarians know about nutrition as what is the evidence supporting the alternative theories and products being promoted? The accusation that vets know little about nutrition, even if it were true, doesn’t invalidate their criticisms. The classis ad hominem fallacy is the strategy of attacking a person and imaging that somehow this attack says anything about that person’s argument. It is the mirror image, in many ways, of the appeal to authority fallacy, which involves claiming some special wisdom or expertise on the part of a person making an argument and then imaging that claim somehow proves the argument. If proponents of raw diets or other unconventional nutritional approaches wish to make a case for their ideas, they have to do it based on logic and facts, not on the presumed expertise of supporters or the supposed ignorance of critics. As always, it is the ideas and the data that matter, not the people involved.

That said, there is a certain hypocrisy to many of these criticisms in that they come from sources with no particular right to claim expertise in nutrition anyway. Proponents of alternative nutritional practices are almost never boarded veterinary nutritionists. Often they are lay people who have labeled themselves as experts without even the training general practice veterinarians have in nutritional science. And while they may not be influenced by the mainstream pet food industry, this only means they are less subject to that particular bias, not that they don’t have other biases. People selling pet food or books on veterinary nutrition are all too often blind to the hypocrisy of claiming their opponents are under the influence of pet food companies while ignoring the fact that they make money selling their own ideas or products.

Others who frequently claim most veterinarians know little about nutrition are themselves general practice veterinarians or specialists in some aspect of veterinary medicine other than nutrition. It may very well be true that they are well-informed about nutrition because they have an interest in it, but this is not evidence that their arguments are true and those of their opponents are false. It is not even evidence that they know more about nutrition than their detractors, who may themselves have studied independently in the area. If you’re not a boarded nutritionist, you can’t claim to be an expert. And whether or not you are an expert, your ideas must stand or fall on their merits and the evidence, not on any presumed superiority in your knowledge over that of your critics.

So I think it is fair to say that most general practice veterinarians have only a fairly general knowledge of veterinary nutrition. And it is fair to acknowledge that much of this information comes from a source with a significant risk of bias, that is the pet food industry. However, I see no evidence that proponents of alternative approaches to nutrition have a reason to claim they know more about nutrition than most veterinarians, or that they are free from biases of their own. Only boarded veterinary nutritionists can legitimately claim to be “experts,” and even this is no guarantee of perfect objectivity or the truth of everything they believe. Claims about who is or is not smart or informed enough to have an opinion on a subject are mostly a superficial distraction from the important elements of any debate, what are the arguments and data behind each position. Awareness of potential bias only serves to make one more careful and cautious in examining someone’s arguments and data, it doesn’t get one a free pass to ignore what they have to say.

This entry was posted in Nutrition. Bookmark the permalink.

25 Responses to What do Veterinarians Know About Nutrition?

  1. zyrcona says:

    You’ve hit the nail on the head with regards to my opinions of this. The aspect I find most offensive about the growing generation of Internet-educated experts is how they attempt to vilify medicine and science as being a massive conspiracy to suppress ‘The Truth'(TM) and write off those who practice them as deluded, brainwashed yes-men. Someone who has earned a degree in a field has worked hard for it, and it disgusts me to hear ad hominem attacks made against such people on the basis of another person spending 15 minutes reading a webpage or a self-published book written by some other person with no such credentials. Anyone can get their uncensored ideas out there these days, and in many ways that’s wonderful, but the unfortunate side of it is that consumers of this information need to develop a critical mindset and some way of filtering it if they’re not to fall victim to scams and cultish memes.

  2. Alexandra says:

    Our vet’s philosophy for cat nutrition is pretty much adapted from Michael Pollan’s for people: Feed them food. Not too much. Decent ratio of protein/fat/carb per AAFCO. If dry food, choose a higher-end brand that has better control over mineral content to minimize risk of FLUTD. IV’s and catheters aren’t fun for anyone.

    I was going to make a comment about how people-nutrition woo tends to infest pet- nutrition woo, but found most of it already addressed in the nutrition section. Have 3 cats, 18, 15, and 3. At least food-wise, so far, so good (other than it’s very hard to control calorie intake when they’re camping out at each other’s bowls…)

    Discovered this blog in a roundabout way and really appreciate it.

  3. Arnold L. Goldman DVM, MPH says:

    Excellent treatment of this subject Brennan! there is little I can add of value except this: The most common, most severe and most significant nutritional disease seen in pet animal practice is not some elemental deficiency but plain and simple, obesity. And in this population of animals, moderate to morbid obesity measurably reduces quality of life, indeed sometimes leads to an early end of life (big dog, obesity related osteoarthritis, becomes non-ambulatory, owner opts early euthanasia). If animal owners practiced pet nutrition self control, a massive reduction in obesity, and therefore nutritionally related disease would surely result. Sadly, many are focused on all sorts of extraneous and marginal or unimportant factors rather than something as simple and obvious as this. “Common things happen commonly” and obesity is the poster child for that aphorism!

  4. skeptvet says:

    Absolutely true. If instead of looking for the “perfect food” pet owners and vets focused on dealing with overfeeding and obesity, we could control by far the most serious and widespread nutritional health problem. Great point.

  5. Pingback: Puppy Food Ratings

  6. Julie says:

    Great post. I know a few years back when I was working as a tech I definitely bought into the internet-based vilification of nutrition education that vets receive, raw diets, the whole kit n’ kaboodle. Realizing how wrong I was and being willing to eat crow and admit that I espoused bad ideas was difficult, but as far as I’m concerned that’s what makes a skeptic – not never being wrong ever, but being willing to change your mind when presented with evidence that you are wrong.

    Re: Obesity. You know, I always assumed (never having owned a cat myself) that based on how many obese cats I saw come through the clinic, it must be incredibly difficult to keep a cat at an appropriate weight. Now that I own a cat that I fostered through a pregnancy and adopting out of her kittens, along with the subsequent weight gain from being on free-choice kitten food through lactation, I have gotten her back down to a BSC of 3 within one year of weaning her kittens. It wasn’t hard; I just did a restricted feed, 2x daily measured amount of food and ignored her cries for more food. It’s that last part that I think owners have such difficulty with. They associate feeding with love and withholding food with withholding love and/or affection. I’m not sure how, as their vets, we can break through that strong association and bonding ritual to create a healthier relationship with food.

  7. skeptvet says:

    as far as I’m concerned that’s what makes a skeptic – not never being wrong ever, but being willing to change your mind when presented with evidence that you are wrong.

    Asolutely! And it’s one of the hardest things to do, so good for you for having that kind of intellectual integrity.

    You’re certainly right that food=love is a big part of the obesity problem. It’s another example of how facts and science don’t always help us convince people to behave in the way that best solves the problem if we aren’t able to communicate with them in a way that also touches their feelings and their values.

  8. Julie G. says:

    I tend to appreciate a good balance between medicine and natural approaches when appropriate. I care pretty greatly for my dogs. I have a 15 year old Golden, 14 year old Border Collie and a 2 year old Rat Terrier. The terrier has recently been diagnosed with allergies (through testing, prompted by clinical presentation…she reacts externally to grass and or dirt). We will start allergy shots soon. They also found some food allergies that are a bit unusual. Of course, it is chicken/turkey and the most common grains found in foods. She is also allergic to the mites you often find in dry kibble. After a very thorough search of what food we could source locally, we determined it was cost prohibitive for us to buy a premade food ($50 for a 15-20 pound sack). My great worry is ensuring she receives adequate nutritional supplementation. The carb, protein, fat balance is pretty straightforward. Where should I go to get good (peer-reviewed) type information when trying to ensure she is adequately nourished? I found your blog, because I appreciate skeptics to help ensure we maintain perspective. Any advice would be greatly appreciated.

  9. skeptvet says:

    The best source of information about nutrition is a board-certified veterinary nutritionist. Dr. Remillard at PetDiets.com has some great info and does consultations, or the nearest veterinary school will have a nutrition department. I have also heard some nutritionists recommend BalenceIt.com.

  10. Dave says:

    What is your opinion on wet vs dry diets for cats from the perspective of water intake. ie Is wet food better because your cat will be more hydrated?

  11. skeptvet says:

    From the point of view of basic principles (physiology, the natural history of the cat, etc), I think it is reasonable to think high moisture and low-carbohydrate diets may be better for cats in general. However, the only actual evidence to support this is for cats with certain specific medical conditions, such as diabetes and kidney disease. So I tell clients with healthy cats that there may be a benefit to feeding canned diets, and while dry diets have some small advantage in terms of dental disease, overall I prefer canned food.

    The key here is that the strength of this recommendation, and all my recommendations, has to be proportonal to the evidence. There isn’t much in this case, so while I do recommend canned diets I don’t support the kind of extreme absolutism of those who say dry diets are poisonous or terrible for cats because there isn’t adequate evidence to support that strong a position.

  12. v.t. says:

    Skeptvet, have you seen any recent evidence regarding canned food and hyperthyroidism in cats? I haven’t seen anything more recent than a year or two ago, so don’t know if this theory is still in discussion?

  13. skeptvet says:

    I’m not aware of anything new, just these papers:

    Martin KM, Rossing MA, Ryland LM, et al. Evaluation of dietary and environmental risk factors for hyperthyroidism in cats. J Am Vet Med Assoc. 2000;217:853–856.

    Edinboro CH, Scott-Moncrieff JC, Janovitz E, et al. Epidemiologic study of relationships between consumption of commercial canned food and risk of hyperthyroidism in cats. J Am Vet Med Assoc. 2004;224:879–886.

    The evidence from epidemiological observational studies is good for suggesting but not proving causation, so I think this is still a pretty tenuous theory. The classic example of why is the strong statistical association between carrying matches and getting lung cancer. It could be argued that matches cause cancer, but clearly this is a confounded association and matches are simply associated with smoking, which is the actual cause. My impression is that mainstream nutrion and endocrinology specialists aren’t very inclined to take the hypothesis that canned food or pthalates cause hyperthyroidism very seriously, but I’m not aware of any more reliable evidence either way.

  14. v.t. says:

    Yes, I had seen those two, but thought I saw a more recent one, cannot for the life of me, remember where. Thanks for your observation!

  15. Pingback: Is Human Food an Absolute No-No for Dogs? | Tasting Dog Food Cuz I Can

  16. Me says:

    My favorite bias is that vets who don’t agree with raw don’t know anything about animal nutrition and are just pet food company shills, but holistic vets who do advocate (and often formulate and sell products) raw obviously know a lot about nutrition and really care about the pet, not the money…

  17. Dale Thompson says:

    First, profound thanks for this web site. It is voluminous so I suspect it takes a lot of time and effort to produce it. Who is SkepVet ? Where did you go to vet school what are your credentials ? Could not find any data on that at this site. Is SkepVet more than one person?

    Re cat food. You prefer the canned but indicate that dry could be good for dental health.
    Aren’t cats obligate carnivores and as such don’t they lack the enzymes to digest plant material ? Moreover, doesn’t dry food introduce the opportunity for artificial and potentially unhealthy chemicals into the feline diet ? I certainly have no research here but my cat owning friends tell me that dry food seems addictive. Cats really love it. No, I mean they really love it. If there is one thing American processors of food know how to do is to engender addictions in humans. Gee, do you think they would be so base and greedy to do that to our pets ? Just a wondering.

    Seems that cats used to be so healthy unlike dogs cats did not go through a period of protracted decrepitude they would just grow old and die. Now I hear about cats with all kinds of odd ball chronic diseases. Of course I think it is caused by the crap that is now in cat food and the wide spread use of dry food. So what do you think SkepVet ?

  18. skeptvet says:

    I’m glad you find the site useful. You can find my credentials on the FAQ page.

    I believe there is a plausible case to be made for canned food being preferable in terms of higher moisture content and lower carbohydrate content, but this is not a solidly demonstrated hypothesis. The idea that dry food reduces dental disease was once popular, but it turns out to be a negligible effect.

    Though cats are obligate carnivores in the wild, they actually can digest many plant compounds perfectly well, including starches and proteins. In the wild this is a neutral or only slightly useful ability (they may eat some of the gut contents of herbivorous prey), but there is strong evidence that plant-based ingredients can be efficiently and effectively utilized. Cats do have a poorer ability to detoxify in general, since their ancestors had little need for this ability, but plant-based nutrients are not inherently toxic. The idea that because of a carnivorous natural history cats cannot have the ability to utilize plant nutrients is a bit like the idea that humans cannot sustain speeds over 20 miles and hour or the experience of flight because in nature we would never experience these; it makes sense but turns out to be untrue. A purely plant-based diet is likely not nutritionally adequate for cats, but some plant-based ingredients can be healthy and nutritious.

    As for “artificial and potentially unhealthy chemicals,” there are a host of assumptions implicit in the phrase that are unproven or untrue. “Natural” and “artificial” are both difficult to define clearly and not good guides to what is “healthy” and “unhealthy.” Nothing more natural that uranium, botulism, and rattlesnake venom, and nothing more artificial than vaccines and antibiotics. The key is that any ingredients included in a diet, of whatever provenance, be tested for safety and nutritional value, and this is the case for most common ingredients in dry and canned cat foods.

    The conflation of processed foods for humans and commercial pet foods is another understandable but mistaken concept. Processed foods for humans are designed for marketability, primarily using basic taste drives (sugar, salt, and fat) and advertising. Nutritional considerations are almost never involved, and the expectation is that people will not be eating any one of these type of foods exclusively. Our nutrition is often atrocious, but not because it is “processed” but because our education and regulatory systems don’t do a good job of steering us towards healthier options. Pet foods have some of the same issues, but those from reputable companies with veterinary nutritionists on staff often make nutritional considerations a major part of designing and producing these foods, and there is a lot of real nutritional research to support this. There may well be healthier options, and I suspect properly formulated and produced homemade diets might have health benefits. But this is as yet an untested hypothesis, and most of the clais about how bad commercial pet foods are are made up and without evidence to back them.

    Seems that cats used to be so healthy unlike dogs cats did not go through a period of protracted decrepitude they would just grow old and die. Now I hear about cats with all kinds of odd ball chronic diseases. Of course I think it is caused by the crap that is now in cat food and the wide spread use of dry food.

    I think there is absolutely no evidence to support this belief. We don’t have good data on health and longevity, but I have exactly the opposite experience. I see my patients living longer and healthier than even 10 years ago, and I see those fed table scraps or left to forage for themselves, as was the rule before the mid 20th century, routinely sicker and less long-lived than those given proper nutrition and healthcare. So while I don’t think any diet now available is perfect, I think the narrative that our pets used to be healthier and now commercial diets have made them sick is completely made up, unproven, and very unlikely to be true.

    Thanks again for the comment.

  19. No one says:

    My own cat is overweight, and we’re trying to get him down but he also cries a lot. We’ve found that it helps a ton just to give him lots of tiny meals throughout the day, including wet food (which seems to keep him satiated), up to the appropriate amount of calories.

    And I think part of the difficulty of ignoring it for a lot of people may be more particularly that you realize that your cat just -doesn’t understand why- you would deny them food. So it’s all the more sad to think of this animal depending on you and waiting for you to help them stop the hunger without any concept of why you won’t come. (It makes me think of those dreams where you’re desperately trying to get someone’s help but they just sit there acting casual like the world ISN’T ending lol :b )

  20. skeptvet says:

    Yes, human psychology is one of the major barriers to healthy feeding of our pets. We love them with food, and denying them food in general, or specific treats, is difficult even when we know that obesity is a major health problem. It is important for vets to find ways for clients to express affection for their pets and expunge their guilt about their pets being hungry in ways that don’t support unhealthy feeding habits.

  21. Ron says:

    I found the below interesting from Wysong.net on their Q/A page.
    Pet Foods Developed by Vets, Breeders, etc.
    All in the above list, with the exception of nutritionists (if they are indeed degreed in the field), have little or no scientific knowledge of nutrition. Veterinarians, at most, usually have only one course in nutrition during their schooling. This is not to say a person cannot be self-taught, but then their expertise should be evidenced by written materials and actual experience in the nutrition field.

    Even “nutritionists” are no guarantee of competence. Nutritionists are responsible for the feeding of instant potatoes, Jello, canned meat, and diet pop to people in hospital beds. They are also behind the myth of 100% complete and balanced pet foods that have caused immeasurable death and suffering in animals.

    It is a simple matter for any pet food producer to talk with professionals in some field, or pay them a fee, and then say the product is “developed by” them.

    So, the claim by pet food companies that they are backed by this or that expert provides very little assurance. Also, it is a simple matter for any producer to talk with professionals in some field, or pay them a fee, and then say the product is endorsed or developed by the expert.

    The proof of competence lies in the product itself and the competence of the producer as evidenced by their written materials. The most important credentials are those of the person(s) who are in charge of the company and who make the final decisions as to how the products are made. Anything else is just name-dropping.

  22. Catharine says:

    I’m a registered dietitian. So I had 4 years of university undergrad study plus 1 year internship to become an expert in human nutrition. Vets have one semester of companion animal nutrition, which pales in comparison. As an evidence-based practitioner, I go by what the evidence says. Yet when it comes to my cats, the evidence just isn’t as strong as it is for human nutrition. I wish there were a cat ‘RD’ I could trust, because, sadly, most vets don’t have the knowledge of nutrition that I have (although they are doctors and I only have a bachelors and masters degree in nutrition – human, of course). When a vet needs to be able to treat multiple species, how can they have adequate nutrition knowledge with only one course? I don’t trust non-vets either, but with no vet equivalent of the RD available to me, I don’t know who to trust for dietary advice for my cats!

  23. skeptvet says:

    The idea that vets only have “one course in nutrition” is propaganda from alternative medicine activists. Nutrition is incorporated into many other courses specifically because, dealing with many different species, vets have to be familiar with the very different nutritional needs of these species. It makes more sense to discuss cattle nutrition in courses on bovine medicine and rabbit nutrition in courses on small mammals than to have a separate nutrition curriculum. So you’ve been misled.

    There are also board-certified veterinary nutrition specialists who do internship and residency training in veterinary nutrition, so if you want a reliable source of information, these would be your best bet. American College of Veterinary Nutrition

  24. MK says:

    As a current veterinary student at an accredited university I can confirm that we are receiving one (1) term of nutrition, divided between general large animal nutrition theory and companion animal medicine. The companion animal medicine was taught by a DVM DACVIM, representative from Morris. The class came off as a sales talk on why kibble is a superior choice, there is no good evidence that cats benefit from a reduced carbohydrate diet (or even a canned diet), and that raw, is obviously going to kill everyone who comes within 10 feet. Just to be clear, my own pets eat Hill’s (and I’m a member of the EBVMA), but this talk was about as biased as one can get. The studies presented often had an n of less than 10 and no controls and graphs he provided in his presentations often didn’t have the axes labeled “see, this number went up, that means it does what I said it did!” No peer-reviewed studies were actually read during the class. Discussion about topics was not encouraged.

    There is an option of an additional elective in companion animal nutrition….taught by the same person. While some of my classmates, including myself, have an interest in nutrition and will seek out additional education on this topic, it’s sadly relatively representative to say that we only receive one required term of nutrition. The discussion of nutrition within other courses is somewhat limited to pathology of outstanding deficiencies or toxicities, for example, white muscle disease, nutritional secondary hyperparathyroidism, copper toxicity, etc.

  25. skeptvet says:

    How frustrating! I had a different experience. In addition to a specific course in nutrition, the subject was integrated into many other courses. We discussed the role of nutrition in treating CKD when talking about kidney disease, the subject of dietary sensitivities and allergies and the various nutritional therapies available for IBD in gastroenterology, the role of diet and supplements in treating osteoarthritis when discussing that disease, and so on. Like all aspects of education, your mileage may vary! 🙂

    Unfortunately, the response I often see to inadequacies in veterinary nutrition training or in veterinarians’ ability to communicate with clients on the subject is a reliance on anecdote, the “wisdom” of internet anecdotes, or the opinion of vets with no more or better training who claim to know more about nutrition than the rest of us by virtue of “doing their own research,” which inevitably means reading books by other alternative medicine docs, selective reading of the primary nutrition literature, or simple uncontrolled trial and error in their own practice. These aren’t very satisfactory or reliable alternatives for pet owners.

Leave a Reply

Your email address will not be published. Required fields are marked *

This blog is kept spam free by WP-SpamFree.