Dr. Marty Goldstein’s Nature’s Feast Raw Diet: A Look at the Infomercial

A client recently asked one of my colleagues for an opinion on an infomercial by Dr. Marty Goldstein for his new commercial raw cat food, Nature’s Feast. There was little new or surprising in this video, but since Dr. Goldstein has a lot of prominence in the media, cat owners may run across this video and be inclined to believe the claims made in it, so I felt it worthwhile to provide some context.

Who is Dr. Marty Goldstein?
I have written a bit about him before as a contributor to the propaganda film The Truth About Pet Cancer, which I havepreviously critiqued in detail

Dr. Goldstein is another celebrity participant, a veterinarian to the stars. He is also a strong advocate of the bait-and-switch known as “integrative medicine.” This means he will sometimes use science-based treatments, but then often gives the credit for any improvement to homeopathy, acupuncture, raw diets, herbs, and other alternative treatments he also employs.

Dr. Goldstein, much like Jean Dodds, is one of those alternative practitioners who is so nice and caring and respected (at least by celebrity clients and alternative medicine advocates) that it is considered almost taboo to point out that much of what he sells is unproven at best and, in some cases, complete nonsense. His use of homeopathy clearly demonstrates his lack of concern for a science-based approach to medicine, and most of the claims he makes about nutrition are unproven at best or clearly wrong at worst.

He justifies his claims almost entirely with personal anecdotes and beliefs, not with any objective scientific evidence. I have discussed the unreliability of anecdotes many times, as well as many of the flimsy arguments he uses in this infomercial, such as the Appeal to Nature Fallacy, so I will only address them briefly here. Dr. Goldstein is clearly convinced that his personal experience and beliefs are sufficient evidence for rejecting the conclusions of scientific research and nutrition experts, and that alone makes any claim he makes suspect.

The most egregious story he tells is about a dog named Kaiser. Dr. Goldstein convinced this dog’s owners to switch form a commercial to a homemade diet. For a couple of weeks after that, supposedly anybody who touched the dog developed a skin rash, and then the dog’s hair all fell out. Rather than seeing this as a problem or a sign of serious illness, Dr. Goldstein interpreted it as a sign the dog was “detoxing,” releasing harmful chemicals through its skin due to the diet change. Such a dangerously bizarre interpretation of potentially serious symptoms does not suggest a rational or reliable medical judgment.

As for the specific claims he makes in his infomercial, here are a few of the most important.

Grains are Bad for Cats
Grains are popular villains in alternative narratives about nutrition these days. The ratio of the three macronutrients—carbohydrates, fat, and protein— are a key element in the formulation of pet diets. None of these are inherently “good” or “bad,” and while the precise balance among them does have health implications, especially in pets with specific medical conditions, such as diabetes or kidney disease, the idea that commercial diets generally contain “too much sugar” or other carbohydrates and that this causes disease is simply not consistent with the evidence. 

Unlike humans, dogs and cats can live with little or no carbohydrate in their diet. However, they can also use this class of macronutrient perfectly well as a source of calories. Some non-digestible carbohydrates (often known as “fiber”) can have beneficial effects on the microbes that live in our pets’ guts, which can influence health, as well as on weight, stool consistency, and other aspects of health. Demonizing an entire class of nutrient is not rational or justified.

As far as the claims that dietary carbohydrates of grains lead to cancer or other disease in pets, these are pure speculation. There are only a few studies looking at diet and cancer risk in dogs and cats, and most of these rely owner recollections for data about diet, which has proven a very unreliable approach in people. There are no studies at all showing restricting dietary carbohydrates reduces the risk of developing cancer in dogs and cats.

There are lab animal studies and epidemiologic research in humans which suggest possible relationships between carbohydrates in the diet and cancer. There are interesting features of the metabolism of cancer cells that suggest diet might have some influence on cancer progression and response to treatment. But there is no real-world, clinical trial evidence that supports the claim that dietary carbohydrates cause cancer in pets or that lower carbs will prevent or help treat cancer. 

Carbohydrates are often seen as particularly dangerous to cats, who are truly obligate carnivores and so would naturally eat a high-fat/high-protein diet with few carbohydrates or grains in it, other than those found in the digestive system of herbivorous prey animals. However, research has demonstrated that cats can make use of carbohydrates in food as an energy source, and that these are not a significant risk factor for diabetes or other diseases often blamed on too much carbohydrate in commercial cat food. 

Perhaps the pet food ingredients most reviled in criticism of commercial pet foods are corn and wheat. The obsession in popular human nutrition lore about gluten has certainly contributed to this. However, many of the fears about gluten, in human and animal health, are unfounded.  People with celiac disease can have negative health effects associated with eating gluten, and there are documented genetic cases of gluten sensitivity in a couple of dog breeds.

However, just as most people are not harmed by eating gluten, there is no evidence that this is a risk factor for disease in dogs and cats. Abandoning wheat as a macronutrient source because of such fears simply leads to the substitution of other sources, and there is no guarantee these are safer or healthier. There is even some evidence that avoiding gluten can cause problems in people who do not have celiac disease. 

I have also heard advocates of alternative diets talk about “the menacing power of corn” as if it were inherently poisonous. This is simply silly, and it ignores decades of nutrition research showing the contrary. Like every other food ingredient, corn is not inherently good or bad. It can contribute calories, protein, and essential fats to the diet, and it can be a safe ingredient in a balanced diet for both dogs and cats. It is obviously not appropriate as the sole food source for our pets, but no one is suggesting we use it that way, and claims that pet foods are “mostly corn” are demonstrably untrue.

Artificial Preservatives
This is a claim I have addressed repeatedly in previous articles. A variety of synthetic antioxidants have been used in pet foods over the years to prevent spoilage, and the risk of food poisoning that goes with it. These substances are sometimes feared as potential causes of cancer based on studies in rats or mice where enormous quantities are fed to the animals to evaluate potential risks. However, extensive research on these substances as they are actually used as preservatives in human and pet foods has failed to find such risks in the real world. This is another example of the dangers in putting too much stock in the predictive value of laboratory studies. 

Some companies have moved to using “natural” preservatives, such as Vitamin E, and this is what Dr. Goldstein recommends. These may be less effective, and there is no clear evidence that they are safer, but the pet food industry is often forced to respond to the fears of consumers, stoked by claims from proponents of alternative diets, regardless of the evidence for or against the concerns. 

Raw Food is Healthier than Cooked Food
This is another claim I have responded to many, many times, and there is still no evidence to support it and plenty of evidence against it. As with most alternative health practices, there are a variety of theories and specific beliefs behind raw feeding, but there are several consistent themes that most proponents of the approach adhere to and use in promoting it.

The first is the claim that commercial diets are nutritionally inappropriate and unhealthy. All of the criticisms of conventional diets I have addressed elsewhere on the blog (e.g. 12) and in detail in my book, are put to the service of convincing people raw diets are a better choice. While commercial pet foods are not perfect or without risks, the evidence clearly shows they are healthy and nutritionally appropriate for the vast majority of dogs and cats, and millions of pets live long and healthy lives eating these foods. 

The other main theoretical argument for raw diets is our old friend the Appeal to Nature Fallacy. The argument runs something like this: Cats are carnivores and they, or their ancestors, ate whole prey in the wild. Evolution has adapted carnivores to this diet, so it is the optimal diet for them. Our pet cats are essentially the same in their nutritional needs as their wild cousins or ancestors, so a diet as much like raw, whole prey as possible is the healthiest diet for them.

Cats have generally been altered far less by their association with humans than dogs. While dogs are most properly classified as omnivores, or facultative carnivores, cats are true carnivores in terms of their anatomy and physiology. Domestic cats do likely have nutritional needs very similar to wild felines. So does this mean they are better off if fed a raw diet?

Well, the Appeal to Nature Fallacy is a fallacy precisely because what happens in nature doesn’t predict what is good or bad in terms of health. The diet wild animals eat is not the perfect diet designed for their long-term health and happiness, it is simply the diet that is available to them. Evolution works by an impersonal process in which animals do their best to meet their physical needs with what is available in their environment and then reproduce. The individuals who are best at meeting these needs leave more offspring and genes behind, and over time the population comes to be more like the more successful individuals because their genes become more common. Species and their environments are always interacting and changing, and there is never an ideal moment in which a species is optimally suited for its environment and every individual is perfectly happy and healthy.

Animals typically live longer, healthier lives in captivity compared to their wild relatives. Wild carnivores frequently suffer from malnutrition, often starving when they can’t catch sufficient prey to meet their calorie and other needs. They also suffer from parasites, infectious diseases, and injuries from catching and consuming whole prey, and they endure this either suffering or die from it. This is not a perfect, blissful state of nature our pets should aspire to, it is simply the way things are in nature. 

Humans no longer live like our stone age ancestors, and we have altered our homes, our clothes, and our diets significantly from that “natural” state. As a result, we suffer less and live longer, healthier lives because of “artificial” practices such as washing and cooking and refrigerating our feed and providing ourselves with nutrients that were once hard to come by. The reduction of scurvy and rickets in modern children compared to those of our ancestors is a good thing, and similarly the reduction in parasites and malnutrition in our pets thanks to “artificial” feeding practices is a positive change. 

Raw feeding is often associated with other alternative medicine beliefs and practices. Surveys show that pet owners who feed raw diets are less likely to trust nutrition advice from veterinarians and are also less likely to adhere to other recommendations, such vaccination and parasite prevention, than owners who feed traditional commercial diets. Veterinarians who promote raw feeding and condemn conventional diets are also often suspicious of vaccines and other science-based medical therapies and frequently advocate alternative medical practices. It is not surprising, then, that theories and beliefs which underlie other alternative practices are also found in arguments for raw diets. 


None of these theoretical justifications for a raw diet, that commercial diets are unhealthy, that our pets are essentially identical to wild carnivores, that a diet as close as possible to that they would eat in nature is best for their health, or that raw food contains some intangible but essential spiritual nutrient lacking in cooked food, hold up very well to logical scrutiny. So is there any actual evidence that raw diets have health benefits?

A few small and short-term studies have been done in which dogs and cats have been fed raw foods. These show some interesting changes in the bacteria living in the guts of these subjects, in stool, and in metabolism and other variables. However, these studies simply show that some small things change when the diet is changed, not that raw diets have meaningful health effects or that whatever effects are seen are due primarily to the lack of cooking. One study has suggested some possible benefits for dental health in dogs fed a raw diet, but another study identified dental disease and broken teeth caused by such diets.

Overall, there is no convincing research evidence to support the theories and claims for why raw diets should be better for our pets than cooked homemade or conventional commercial diets. 

Unlike the benefits of raw diets, which are theoretical and unproven, the risks are well documented. Commercial raw diets which meet industry standards are likely to be nutritionally complete, but many raw advocates feed home-prepared diets, and just like other homemade foods, these diets are frequently nutritionally unbalanced and incomplete. There is even one report of a whole-prey diet (whole ground rabbit) which was studied in cats as a representative of a “natural” diet but which turned out to generate severe heart disease due to taurine deficiency in the cats eating it. So much for “natural” meaning “healthy!” 

The most significant risk of raw diets is from food-borne infectious disease. Numerous studies have shown raw diets to be frequently contaminated with potentially dangerous bacteria. While such pathogens can contaminate cooked diets as well, the risk is significantly higher for raw foods. Other studies have shown that animals eating these diets often shed these dangerous organisms in their feces, which exposes humans and other animals to the risk of infection.

Most importantly, serious illness and death in cats and dogs, and in their owners, have been caused by pathogens found in raw pet diets. While the number of confirmed cases of pets and humans suffering or dying from food-borne illness caused by raw diets is small, this is a very serious health hazard. While healthy adult pets may be able to resist these organisms to some extent, there is no absolute immunity in dogs and cats to food-borne illness. Very young, old, and sick animals, and their human caregivers, are at even higher risk. 

Dr. Goldstein claims that the freeze-drying of his pet food “completely eliminates” this risk, but that is just his opinion based on anecdote, and this is disputed by both veterinary nutritionists and veterinary infectious disease specialists

He also claims that cooking destroys nutrients in food, including taurine, which is essential for normal heart health in cats. He claims that the vitamin supplementation done to compensate for this is not effective, but there is ample evidence this is untrue and that supplementation prevents any micronutrient deficiencies in commercial diets. In fact, his claim that cardiomyopathy, or heart muscle disease, is common due to taurine deficiency is completely false. Taurine deficiency can case a disease called dilated cardiomyopathy (DCM) in cats, but this disease has almost completely disappeared since commercial diets are supplemented with taurine (unlike the cats eating whole rabbit carcasses, who did develop it in one study). Hypertrophic cardiomyopathy is an entirely different heart disease, which is still fairly common, but this is not associated with taurine deficiency, and Dr. Goldstein appears to be mistakenly conflating the two conditions in his ad.

Euthanized Pets in Commercial Pet Food
This is perhaps the most extreme example of efforts to frighten pet owners about commercial diets. Promoters of this story take a few facts and weave them into an unlikely, but shocking narrative. Most countries have pretty strict regulations about the ingredients that can go into commercial pet foods, and these broad rules cover the use of euthanized animals as a food ingredient even if this is not explicitly mentioned in the law. Industry groups, as well as regulators, also have policies prohibiting this practice. Even apart from such rules and policies, though, the claim makes little sense for other reasons.

Food animals, such as cattle, pigs, sheep, and poultry, are the most common and economical source of animal ingredients for pet foods. These are mostly produced in large operations intended to produce food for humans. Apart from being an ethically terrible and unhealthy ingredient for pet foods, euthanized dogs and cats, presumably harvested from animal shelters or picked up by the roadside, would be an unreliable and expensive raw material compared to the ingredients produced by the food animal industry. And, of course, any company caught using dead pets in their pet food would be destroyed by public outrage and likely run out of business. What motivation these companies might have, then, for using such an ingredient is hard to fathom.

There have been several attempts to investigate commercial pet foods and look for evidence of dog or cat DNA, which might suggest there is some truth to this claim. So far, however, none of these investigations have found evidence that cats and dogs have been used as components of pet foods. The U.S. Food and Drug Administration (FDA), for example, found no evidence of dog or cat DNA in pet foods it tested in 2002. While this can’t definitively prove this practice never happens, it is yet another piece of evidence against it.

So how did this idea get started? It’s impossible to know for certain, but the evidence often cited in support of the claim that euthanized pets are used in pet food tends to be open to interpretation, and those inclined to be suspicious of commercial diets and the companies that produce them seem to take the darkest possible view of this evidence. 

For example, most of the laws and regulations that would prohibit using euthanized pets in pet food don’t actually address that issue directly. The law doesn’t explicitly prohibit the practice precisely because there’s little evidence it is actually occurring. Instead, the laws prohibit unsanitary and unsafe ingredients, potentially dangerous chemicals such as euthanasia drugs, and other general types of ingredients which would naturally include euthanized dogs and cats. Critics of commercial pet foods tend to claim that because the practice isn’t named in the regulations it must actually be happening, which is not a particularly convincing claim.

Animals euthanized at shelters or killed by cars and not claimed are sometimes disposed of at rendering plants, where the bodies are broken down at high temperature into basic components, such as fats and simple proteins. These components are used in a variety of ways, from fats used as industrial lubricants to proteins being used in shrimp and fish farming. This is considered a more environmentally acceptable means of disposal than burning or burying the remains, but it is understandably disturbing to think about. 

Because the parts of food animals not eaten by people are also rendered and are sometimes used in pet foods, there have been concerns that rendering products from euthanized dogs and cats might make their way into pet diets. This is prohibited, again by both regulations and industry policies, and there has not yet been any conclusive evidence that it occurs, but this may be one source of the belief that deceased pets are used as pet food ingredients.

Another, and very serious issue is that the drug pentobarbital, an anesthetic originally used for surgery but now most often used for euthanasia, does sometimes turn up as a contaminate in pet foods. In most of these instances, the amount has been too low to be considered a hazard, but there have been rare cases in which dogs have been sickened and even killed but pentobarbital in canned foods. Investigations into the source of this contamination have typically traced it to the accidental inclusion of euthanized cattle or horses in rendering products intended as pet food ingredients. Once again, no evidence has yet been found showing that euthanized dogs and cats have been the source of pentobarbital contamination of pet foods, but again this may be one source of the belief that this is happening. 

Ultimately, like so many of the concerns raised by critics of science-based medicine and conventional nutrition, it is not possible to conclusively prove that the concern is never true under any circumstances. However, the consistent failure to find evidence for the claim despite repeated investigations over decades certainly makes it an unlikely occurrence and not a reason to fear commercial diets or choose untested alternatives with far less evidence for their safety and nutritional value.

Miscellaneous Claims
Dr. Goldstein uses fear to promote his claims. He tells a sad story about the death of one of his cats from urinary tract obstruction, and claims that commercial cat food caused this, but there is little evidence to support such a claim. He also claims that “more cats are getting sick than ever before,” which is the same kind of mythologizing of the “good old days” that alternative vets often peddle to make people fear the health effects of modern life. I have addressed this claim before in regards to cancer in pets, and there is no evidence to support it and some to suggest that our pets, like us, are healthier than in the past.

Dr. Goldstein also argues that cats should be fed organ meats high in Vitamin D partly because they may become deficient from living indoors or in cold climates due to inadequate sun exposure. This is an idea translated directly from human physiology that simply doesn’t apply to cats. While humans make a lot of our Vitamin D in our skin under the influence of sunlight, cats do not, and they always need to get this from dietary sources regardless of lifestyle (e.g. 34). As I have already mentioned, there is plenty of evidence that cooked commercial diets meet this need effectively.

Bottom Line
Dr. Goldstein is basically trying to sell both a product and the ideology behind it in this infomercial. While I have no doubt he is sincere, there is plenty of reason to doubt he is correct. His claims are based on faulty reasoning and anecdote and often contradicted by established scientific knowledge. There are clear risks to raw diets such as Nature’s Feast, and there is yet no real evidence for any of their purported benefits. Advocates of these diets would better serve the pet population by supporting legitimate, rigorous research to show definitively whether their claims are true or not than by inventing and selling products based on gut feelings and anecdotes and ignoring the science and the real nutrition experts.

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32 Responses to Dr. Marty Goldstein’s Nature’s Feast Raw Diet: A Look at the Infomercial

  1. Steph says:

    I do understand why some people may prefer to prepare homecooked meals for their pets. That way they can choose high quality ingredients fit for human consumption and, thus, can control what goes into their pets. It’s basically a trust issue, and I honestly think it makes sense: when a person have a kid, they know they will have to cook for them. Why would it be different for a pet? However, I don’t understand why people tend to prefer raw homemade diets to cooked homemade diets. That’s beyond comprehension…

    Btw, which do you think is better: homemade cooked diets (properly formulated by a vet nutritionist) or commercial diets? Even without actual evidence, do you think that, in theory, one may be better that the other?

  2. skeptvet says:

    In thee absence of evidence, I can just guess. I think it is a plausible theory that fresh foods could have health benefits compared with commercial diets if the issues of nutritional adequacy and quality control could be sorted out, and my guess would be that this is true.

    However, I don’t think the term “high-quality ingredients” you use has any real meaning. It is just a way of saying that some ingredients look more appealing or “healthier” to you than others, but our gut feelings about such things aren’t a reliable guide to what is healthy. My grandmother felt that lots of heavily cooked meat looked healthier than “rabbit food” (aka vegetables) because that was the cultural standard of her place and time. I’ve seen interviews with hunter-gatherers from Africa who reveled in drinking pure melted cow fat, and in the subsequent diarrhea, because they felt this was a fortifying and healthy food. Our “instincts” about such things are mostly arbitrary cultural prejudices, and not as reliable as science, which is why some people’s gut feeling that raw is “healthier” or “more natural” than cooked food is no more nor less arbitrary than whatever you or I think of as “high-quality” or “low-quality” ingredients.

  3. Steph says:

    Hi, thanks for the reply! When I said “high quality” I was just referring to ingredients that have stricter rules of control and are thus fit for human consumption. I was not comparing types of ingredients (grains versus meat, for example), but rather human grade versus feed grade ingredients. What I meant was that, for example, the beef meat found in the supermarket has certainly a stricter quality control that the beef meat found in pet foods. Maybe there’s no real nutritional or health difference at all between the two, but some owners may prefer to play safe and pick the human grade ingredients.

  4. skeptvet says:

    The problem, as you say, is that being “human grade” doesn’t necessarily mean an ingredient is better nutritionally or in terms of health effects of safety, so it is more of a marketing term than a useful guide for pet owners, and it is perfectly possible to create a diet will all human grad ingredients that is unhealthy, so it is unfortunate that the term and the concept carry the weight in people’s minds that they due. Here is an excellent discussion of this term by a veterinary nutritionist.

  5. Maryann Adams says:

    While i agree with much of what you say, please read and comment. There are documents on FDA website explaining that euthanized animals are allowed. https://www.fda.gov/about-fda/cvm-foia-electronic-reading-room/appendix-dog-food-samples-used-cvm-pentobarbital-surveys-and-analytical-results
    this is from FDA about finding euthanasia drugs in dog food: https://www.fda.gov/about-fda/cvm-foia-electronic-reading-room/appendix-dog-food-samples-used-cvm-pentobarbital-surveys-and-analytical-results

  6. skeptvet says:

    Euthanized animals are not permitted in pet food: “we do not allow the use of animals euthanized with a chemical substance such as pentobarbital in the manufacture of pet foods.” Obviously, pentobarbital has been detected in pet foods sporadically, and the source has never been definitively confirmed. The most reasonable hypothesis is that euthanized horses and cattle processed at rendering plants for other intended uses are mistakenly, or perhaps deliberately, redirected into the pet food supply chain at the rendering plant. The levels have typically been extremely low and, again, this is not legal or permitted nor a widespread phenomenon. There have been a few cases of some foods containing high enough levels of pentobarbital to cause harm, and of course this should be investigated, prosecuted, and prevented.

    The problem, however, is that this is not a major health risk to the pet population that justifies avoiding commercial diets and selecting raw foods or other diets with even greater risks, and this is how the problem is used by Dr. Goldstein and other advocates of alternative diets. It is appropriate to point out potential health risks to commercial diets and to encourage better measures to prevent these, but it is not appropriate to exaggerate them, to ignore the context that the overwhelming majority of such diets are safe and healthy, or to suggest that raw and other alternative diets are safer.

  7. Casey says:

    I am a vet tech student working at a pet food store and there is one thing raw food advocates and pro-raw coworkers keep claiming that does not make sense to me. They claim that food allergies come from processing, a dog that is allergic to chicken in kibble can handle raw chicken because it is less processed. I feel like that’s not true but I haven’t been far enough in my schooling to back it up. Does processing really make the allergy?

  8. JCM says:

    The fallacical reasoning behind mistrusting marketing from kibble companies while trusting implicitly the marketing behind raw food companies is….really something.

    For instance, if putting euthanized pets in dog food is a concern why wouldn’t raw food companies also be suspected of doing it?

    Thanks as always Skeptvet for your work.

  9. skeptvet says:

    Nope! They are completely making that up, and it makes no biological sense.

  10. no one says:

    Re: raw vs cooked and food allergies:

    I was looking up papers on food allergies, and there was evidence that proteins that didn’t cause allergy initially, might end up causing allergy after processing because they might consistently reconform (e.g. due to heat or whatever processes) in such a way that they now set off the patient’s immune system.
    Do you have any thoughts on this?

  11. skeptvet says:

    The claim that raw metas are intrinsically less allergenic than cooked meats isn’t true. Cooking can affect the allergenicity of proteins, but the specific effects depend on the protein, the cooking, the individual, and lots of other factors. There are some studies in both humans and dogs showing cooked proteins are LESS allergenic than raw:

    Heat treatment modifies the allergenicity of beef and bovine serum albumin.
    Allergy. August 1998;53(8):798-802.
    A Fiocchi 1, P Restani, E Riva, G P Mirri, I Santini, L Bernardo, C L Galli

    Article Abstract

    The effect of heat on the allergenicity of beef and bovine serum albumin was investigated among 10 toddlers skin prick test (SPT)-positive to raw and cooked beef. The meat-allergy diagnosis was confirmed during double-blind, placebo-controlled food challenge (DBPCFC) with 180 g of beef cooked for 5 min at 100 degrees C. SPT with homogenized and freeze-dried beef, and heated and unheated bovine serum albumin were performed. Both heated and unheated bovine serum albumin, homogenized beef, and freeze-dried beef were used in trial DBPCFC. All children were SPT-positive to unheated bovine serum albumin. Seven were positive to heated bovine serum albumin, one to freeze-dried beef, and none to homogenized beef. DBPCFCs were negative for homogenized beef and freeze-dried beef, positive for unheated bovine serum albumin in five patients, and positive for heated albumin in four children. We conclude that heating reduces sensitization to beef and bovine serum albumin but does not abolish reactivity to albumin under home conditions. However, industrially heat-treated and sterilized homogenized beef and freeze-dried beef may be suitable substitutes in beef-allergic children’s diets.

    View in a new window
    Meat allergy: II–Effects of food processing and enzymatic digestion on the allergenicity of bovine and ovine meats.
    J Am Coll Nutr. June 1995;14(3):245-50.
    A Fiocchi 1, P Restani, E Riva, A R Restelli, G Biasucci, C L Galli, M Giovannini

    Article Abstract

    OBJECTIVES: This study was designed to evaluate whether peptic treatment of BSA and OSA affects their allergenicity and to evaluate the effect of technological treatments of meat for infant feeding on the allergenicity of these proteins.

    SUBJECTS: Twelve children (8 males and 14 females) suffering from atopic dermatitis (AD), aged 12 months to 4.33 years (mean age 2.21 +/- 1.05 years).

    STUDY DESIGN AND METHODS: Children suffering from atopic dermatitis (AD), (AD), clinically reactive and SPT-positive to beef, underwent skin prick testing (SPT) and radioallergosorbent test (RAST) with BSA and OSA, before and after peptic treatment. They were tested also with commercially available homogenized bovine meat (HBM) and with freeze-dried bovine (FDBM) and ovine (FDOM) meats. Peptic digestion of BSA and OSA was carried out in a Dubnoff’s water bath containing 0.05 mg/ml of pepsin. SPT and RAST were performed for 1 mg/ml of BSA and OSA digested 5 minutes, 2 hours and 4 hours with pepsin; homogenized bovine meat, and FDBM and FDOM. SPT results were expressed as diameters (in mm) of the wheal obtained after SPT; a diameter > or = 3 mm was considered as positive. RAST was considered positive for IgE values 5 > UI/ml.

    RESULTS: SPT to native BSA and OSA were positive in all patients. Only 2 of the 12 children were SPT-positive to HBM, FDBM, and FDOM. After digestion, SPTs and were positive as follows: for BSA, 4/12 after 5 minutes peptic treatment, 2/12 after 2 hours and 2/12 after 4 hours; for OSA, 3/12 after 5 minutes peptic treatment, none after 2 and 4 hours. None of RASTs was positive after peptic attack.

    CONCLUSIONS: Both proteolytic digestion and technological treatment reduced the allergenic potential of meat products.

    Patch testing and allergen-specific serum IgE and IgG antibodies in the diagnosis of canine adverse food reactions.
    Vet Immunol Immunopathol. February 2012;145(3-4):582-9.
    DOI: 10.1016/j.vetimm.2012.01.003
    Simone Bethlehem 1, Jennifer Bexley, Ralf S Mueller
    Copyright © 2012. Published by Elsevier B.V.

    Article Abstract

    Adverse food reaction (AFR) is a common differential diagnosis for pruritic dogs. The only way to diagnose AFR is an elimination diet of 6-8 weeks with a protein and a carbohydrate source not previously fed. In humans, patch testing has been shown to be a useful tool to diagnose food allergies. In veterinary medicine, serum food allergen-specific antibody testing is widely offered to identify suitable ingredients for such diets. The aim of this study was to determine sensitivity, specificity, negative and positive predictability of patch testing with and serum antibody testing for a variety of common food stuffs. Twenty-five allergic dogs underwent an elimination diet and individual rechallenge with selected food stuffs, food patch testing and serum testing for food-antigen specific IgE and IgG. Eleven clinically normal control dogs only were subjected to patch and serum testing. The sensitivity and specificity of the patch test were 96.7 and 89.0% respectively, negative and positive predictability were 99.3 and 63.0%. For IgE and IgG the sensitivity was 6.7 and 26.7%, specificity were 91.4 and 88.3%, the negative predictive values 80.7 and 83.7% and the positive predictive values were 15.4 and 34.8%. Based on these results, a positive reaction of a dog on these tests is not very helpful, but a negative result indicates that this antigen is tolerated well. We conclude that patch testing (and to a lesser degree serum testing) can be helpful in choosing ingredients for an elimination diet in a dog with suspected AFR.

    Effects of two different domestic boiling practices on the allergenicity of cow’s milk proteins.
    Language: English
    J Sci Food Agric. April 2018;98(6):2370-2377.
    Cristina Lamberti 1, Cristina Baro 1, Marzia Giribaldi 1, Lorenzo Napolitano 1, Laura Cavallarin 1, Maria Gabriella Giuffrida 1

    © 2017 Society of Chemical Industry.
    Article Abstract
    BACKGROUND:
    The sale of raw drinking milk through automatic dispensers is permitted in some EU member states, but consumers are usually advised to boil the milk before consumption. The present study has been conducted to evaluate the effects of two common domestic boiling techniques on the proteins of raw milk and, in particular, on their potential allergenicity.
    RESULTS:
    Native one-dimensional electrophoresis, N-terminal amino acid sequencing and immunoblotting have been used to characterize the protein pattern and to evaluate the possible changes in the allergenic properties of the processed milk. The main result of this investigation is that heating induces the aggregation of ?-lactoglobulin in higher-molecular-weight products, while caseins seem to be more resistant to the treatments. ?-Lactoglobulin aggregates have been found to be non-immunoreactive with the sera of subjects suffering from cow’s milk protein allergy.
    CONCLUSION:
    Domestic boiling modifies the milk protein profile, causing a minor reduction in milk allergenicity.

  12. skeptvet says:

    The claim that raw metas are intrinsically less allergenic than cooked meats isn’t true. Cooking can affect the allergenicity of proteins, but the specific effects depend on the protein, the cooking, the individual, and lots of other factors. There are some studies in both humans and dogs showing cooked proteins are LESS allergenic than raw:

    Heat treatment modifies the allergenicity of beef and bovine serum albumin.
    Allergy. August 1998;53(8):798-802.
    A Fiocchi 1, P Restani, E Riva, G P Mirri, I Santini, L Bernardo, C L Galli

    Article Abstract

    The effect of heat on the allergenicity of beef and bovine serum albumin was investigated among 10 toddlers skin prick test (SPT)-positive to raw and cooked beef. The meat-allergy diagnosis was confirmed during double-blind, placebo-controlled food challenge (DBPCFC) with 180 g of beef cooked for 5 min at 100 degrees C. SPT with homogenized and freeze-dried beef, and heated and unheated bovine serum albumin were performed. Both heated and unheated bovine serum albumin, homogenized beef, and freeze-dried beef were used in trial DBPCFC. All children were SPT-positive to unheated bovine serum albumin. Seven were positive to heated bovine serum albumin, one to freeze-dried beef, and none to homogenized beef. DBPCFCs were negative for homogenized beef and freeze-dried beef, positive for unheated bovine serum albumin in five patients, and positive for heated albumin in four children. We conclude that heating reduces sensitization to beef and bovine serum albumin but does not abolish reactivity to albumin under home conditions. However, industrially heat-treated and sterilized homogenized beef and freeze-dried beef may be suitable substitutes in beef-allergic children’s diets.

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    Meat allergy: II–Effects of food processing and enzymatic digestion on the allergenicity of bovine and ovine meats.
    J Am Coll Nutr. June 1995;14(3):245-50.
    A Fiocchi 1, P Restani, E Riva, A R Restelli, G Biasucci, C L Galli, M Giovannini

    Article Abstract

    OBJECTIVES: This study was designed to evaluate whether peptic treatment of BSA and OSA affects their allergenicity and to evaluate the effect of technological treatments of meat for infant feeding on the allergenicity of these proteins.

    SUBJECTS: Twelve children (8 males and 14 females) suffering from atopic dermatitis (AD), aged 12 months to 4.33 years (mean age 2.21 +/- 1.05 years).

    STUDY DESIGN AND METHODS: Children suffering from atopic dermatitis (AD), (AD), clinically reactive and SPT-positive to beef, underwent skin prick testing (SPT) and radioallergosorbent test (RAST) with BSA and OSA, before and after peptic treatment. They were tested also with commercially available homogenized bovine meat (HBM) and with freeze-dried bovine (FDBM) and ovine (FDOM) meats. Peptic digestion of BSA and OSA was carried out in a Dubnoff’s water bath containing 0.05 mg/ml of pepsin. SPT and RAST were performed for 1 mg/ml of BSA and OSA digested 5 minutes, 2 hours and 4 hours with pepsin; homogenized bovine meat, and FDBM and FDOM. SPT results were expressed as diameters (in mm) of the wheal obtained after SPT; a diameter > or = 3 mm was considered as positive. RAST was considered positive for IgE values 5 > UI/ml.

    RESULTS: SPT to native BSA and OSA were positive in all patients. Only 2 of the 12 children were SPT-positive to HBM, FDBM, and FDOM. After digestion, SPTs and were positive as follows: for BSA, 4/12 after 5 minutes peptic treatment, 2/12 after 2 hours and 2/12 after 4 hours; for OSA, 3/12 after 5 minutes peptic treatment, none after 2 and 4 hours. None of RASTs was positive after peptic attack.

    CONCLUSIONS: Both proteolytic digestion and technological treatment reduced the allergenic potential of meat products.

    Patch testing and allergen-specific serum IgE and IgG antibodies in the diagnosis of canine adverse food reactions.
    Vet Immunol Immunopathol. February 2012;145(3-4):582-9.
    DOI: 10.1016/j.vetimm.2012.01.003
    Simone Bethlehem 1, Jennifer Bexley, Ralf S Mueller
    Copyright © 2012. Published by Elsevier B.V.

    Article Abstract

    Adverse food reaction (AFR) is a common differential diagnosis for pruritic dogs. The only way to diagnose AFR is an elimination diet of 6-8 weeks with a protein and a carbohydrate source not previously fed. In humans, patch testing has been shown to be a useful tool to diagnose food allergies. In veterinary medicine, serum food allergen-specific antibody testing is widely offered to identify suitable ingredients for such diets. The aim of this study was to determine sensitivity, specificity, negative and positive predictability of patch testing with and serum antibody testing for a variety of common food stuffs. Twenty-five allergic dogs underwent an elimination diet and individual rechallenge with selected food stuffs, food patch testing and serum testing for food-antigen specific IgE and IgG. Eleven clinically normal control dogs only were subjected to patch and serum testing. The sensitivity and specificity of the patch test were 96.7 and 89.0% respectively, negative and positive predictability were 99.3 and 63.0%. For IgE and IgG the sensitivity was 6.7 and 26.7%, specificity were 91.4 and 88.3%, the negative predictive values 80.7 and 83.7% and the positive predictive values were 15.4 and 34.8%. Based on these results, a positive reaction of a dog on these tests is not very helpful, but a negative result indicates that this antigen is tolerated well. We conclude that patch testing (and to a lesser degree serum testing) can be helpful in choosing ingredients for an elimination diet in a dog with suspected AFR.

    Effects of two different domestic boiling practices on the allergenicity of cow’s milk proteins.
    Language: English
    J Sci Food Agric. April 2018;98(6):2370-2377.
    Cristina Lamberti 1, Cristina Baro 1, Marzia Giribaldi 1, Lorenzo Napolitano 1, Laura Cavallarin 1, Maria Gabriella Giuffrida 1

    © 2017 Society of Chemical Industry.
    Article Abstract
    BACKGROUND:
    The sale of raw drinking milk through automatic dispensers is permitted in some EU member states, but consumers are usually advised to boil the milk before consumption. The present study has been conducted to evaluate the effects of two common domestic boiling techniques on the proteins of raw milk and, in particular, on their potential allergenicity.
    RESULTS:
    Native one-dimensional electrophoresis, N-terminal amino acid sequencing and immunoblotting have been used to characterize the protein pattern and to evaluate the possible changes in the allergenic properties of the processed milk. The main result of this investigation is that heating induces the aggregation of ?-lactoglobulin in higher-molecular-weight products, while caseins seem to be more resistant to the treatments. ?-Lactoglobulin aggregates have been found to be non-immunoreactive with the sera of subjects suffering from cow’s milk protein allergy.
    CONCLUSION:
    Domestic boiling modifies the milk protein profile, causing a minor reduction in milk allergenicity.

  13. Martha Waltien says:

    Since 2014 (this is Feb 2020) we have been exclusively feeding our 14 cats a raw homemade, home ground diet as found in these sites: feline-nutrition.org; catinfo.org (Lisa Pierson DVM) and rawfeedingforibdcats.com.
    One cat had suspected IBD, with chronic vomiting and diarrhea that went on for 7 of his 9 years. These symptoms completely stopped , again, at age 9, once he was fed only this recipe. At age 14, he was starting to vomit and a biopsy confirmed IBD and he is treated with Budesonide and is still only raw fed and symptom free with the use of this drug. Two internal medicine specialists have cared for our 14 year old FIV+ cat, diagnosed CKD in 2014. They each felt he is thriving on the raw, had been skeptical about raw but are enthusiastic about what our cat eats because of his BP, lab work and excellent body mass. These vets work at one of the most famous teaching and research hospitals in the world. We keep the phosphates low because we use a bone substitute, our home powdered egg shells, and eliminate raw egg from his diet. (We do the same with our cats over age 10, due to the aging kidneys. ) This is all anecdotal and I have no data to present but the appearance and behavior of our cats has truly improved for the better ever since we started to feed them this homemade recipe which is completely uncooked.
    I want to comment on the question of the natural diet for a cat. I cannot prove it but I have suspicion very much so that the carbohydrates which are found in dry and canned cat food are inflammatory to the intestines of a cat. To me, common sense tells you that you want to feed a cat a diet that is as close as possible as to what they would eat in the wild and we know that cats don’t eat plants in the wild except where the contents of the stomach of a prey. Many years ago, we fed as much as 50% dry food and the rest canned food to the 2 cats who are now 16 and who have been formally diagnosed with IBD. I can’t prove it, but I am suspicious that the high carbohydrate content of the dry food especially, 60% carbs in dry, and also even in the canned food, may well have caused chronic inflammation in the intestinal walls. Time will tell and let us know if the other cats develop IBD as they age. We bet not. Most of them have not had any dry food in their lives and only canned food for a year or two.
    A final comment which is that two veterinarians told me that they “never see cats that look like ours”. They said that their coats are so thick and glossy and the musculature is so well developed. One veterinarian told me that at this point all of the other cats she sees, who have had CKD that long, have much more wasted bodies. She said she has literally never seen a CKD
    cat, before ours, diagnosed for so long, who didn’t have a part wasting. Our CKD cat has absolutely no wasting and very well developed muscles.
    (One of the things that we both noticed was that, after about 6 months of eating only raw food, our many cats developed thicker coats of fur, the muscles became larger, especially noticeable in the rear thighs,
    and they had less fat. One cat really has changed dramatically. We used to call him “tubby” because he was too fat. On raw, he still eats a lot but now his weight is almost perfect. We never thought we would ever see him look like that! In fact, we have no cats that are obese anymore, whereas before , some of them were overweight on the canned food. I wonder if cats eating canned or dry food need to eat more to get the nutrients that they need. And so they eat too many calories. I know that what I’m saying is not scientifically in any way demonstrated but I have to make these comments because of what we have experienced. The pet food industry is not going to fund the kind of studies that are needed to compare the homemade recipe that we use with commercial raw food or canned or dry food. I think it’s very important to not compare commercial raw food with homemade raw. We buy all of the meat in mainstream supermarkets. We also get organ meat in Chinese supermarkets. They never get sick from it, love it and they don’t get diarrhea from the food.

  14. Heather Huston says:

    Martha Waltien I would love to see some of your recipes! You’ve found success in a way I would like to try. We only have one kitty, but after only being on Science Diet dry food since we rescued her as a kitten, we had to start giving her Science Diet “Perfect Weight” because she got fat. She has not lost any weight on the Perfect Weight blend, which she’s been on for at least a year now. She has dry skin and sheds quite a bit of fur, I would love so see that resolved by a change in diet. I’m willing to do the work.

  15. skeptvet says:

    Homemade diets are often nutritionally incomplete and unbalanced, so they should only be formulated by board-certified veterinary nutritionists. I would argue that Martha hasn’t “found success,” because anecdotes and personal experience are deeply unreliable and misleading. Her theories about carbohydrates are not accepted by the true experts in veterinary nutrition, and it will take more than individual anecdotes to show they are true or useful.

  16. john says:

    Curious to hear you comment on the sadly misleading marketing of grain-free diets, which are actually bad for dogs, and the science is becoming increasingly clear on that — not anecdotal.

    Also curious if you see particular proteins triggering allergy responses more than others. I have heard many pet food stores say to stay away from chicken, but I’ve never seen real evidence of that.

  17. skeptvet says:

    I’ve written a bit about grain-free diets. They are an excellent example of how bad logic and a lack of evidence can lead too real harm.

    No real evidence any particular protein is more or less allergenic than other. The most common allergens tend to be the most common food ingredients.

  18. Lisa Wood says:

    Hi. I would just like to know the best food to feed my cats and dogs. Thank you. I do have a Lhasa with some joint issues, he is 13. Thank you. Lisa

  19. skeptvet says:

    Unfortunately, there is no answer to your question. There is no one “best food” for dogs generally or for any specific dog. There may be benefits to some ingredients, formulations, or forms of food, but the evidence for this is often weak. A low-protein, high-fat food may be better for a dog with kidney disease than for a growing puppy. Broad generalizations about good and. bad foods or ingredients are a major part of the problem with nutritional misinformation. Most dogs can thrive on many different brands or types of food, but each its an individuals so some trial and error is needed.

    If you really want a good explanation of why the question hides a lot of complexity, I suggest reading Dog Food Logic by Linda Case.

  20. Mona Kufalk says:

    I read this article and the responses to it. Thank you. I had just listened to Dr. Marty’s video presentation and was researching his food and others. I will not be buying what he is selling. I have a 12 year old cat with renal issues and she is now on a low protein diet. I have three other cats and would like to know if a “topper” or supplement on their food would be beneficial. Our vet says what cats need and love is mouse brains..and jokingly says a cat food called mouse brains just wouldn’t sell. Your thoughts?

  21. skeptvet says:

    There isn’t much reason to think any addition to a balanced and complete commercial diet is necessary for health, but there isn’t anything wrong with giving your cats something if they enjoy it. So long as such toppers are less than about 10% of their total calories, they won’t have any negative impact on overall nutrient balance. I would, however, avoid anything raw (like mouse brains) due to the risk of infection and parasites. 🙂

  22. Miriam Wolfe says:

    My cats catch and eat mice, moles, and chipmunks, but don’t eat the heads, tails and an organ that looks to me like a liver. What would make them omit that organ?

  23. skeptvet says:

    Great question. Bear in mind that your cats are probably also fed by you, so their hunting may be less about hunger and more behavioral, so they may be less motivated to eat the difficult or less appealing parts of prey than a feral feeding itself. In general, wild carnivores typically do eat the organs, such as the liver, though not always the stomach and intestines. Not really sure, but those would be my thoughts.

  24. Thomas A Guiliani says:

    Seems subscribe link doesn’t work, but do respect your opinion and would like to subscribe, cat cohabitant here. 1st one lived to be 22+, current one is almost 15. Both Persians, both fed only Science Diet, primarily dry foods.

  25. Barbara Kantrud Lerma says:

    So frustrated and so many different answers. Huge animal lover. My cat is almost 18. Got her from a bit of neglect passed away elderly at 7. In and out of drs forever until they found it was IBD. She was wasting away. Through many bouts and tries I’ve been giving her shots of DexSol for years. A dr over a year ago found throat lump and next stop radio active therapy at 16. Only because she was amazed at her ex rays, labs and physical. Thick beautiful hair and thought she was about 7-8. Chip found she was 16. Anyway then thyroid stopped.she went from normal 9 to 11 pounds. Iwishi could find ANY food to give her to not give her shots. Pills were impossible so gave up to shots. Now they want me to supplement thyroid as she’s very low and very less active. Tried every food when she was 6 pounds 7ounces and spine sticking out, cried vomited and she was very picky about all foods. Shots got her to eat a little and royal canon she finally really liked. Now vet changed her to satiety support. She’s not excited but eats. Of course too many ingredients so What IsRight. Was willing to try this Dr.s raw food but now you guys have me scared of that. What is good for this sweet girl that finally got someone to help her pain halfway through her life?

  26. skeptvet says:

    I’m sorry you’re going through all of this. The frustrating reality of medicine is that there is always uncertainty, and we don’t always get the level of control of things we would like. The difference between what your doctors have done for you and the kind of thing Dr. Marty is offering is the difference between making the best decision we can based on scientific information, however imperfect, versus making decisions based on promises and hopes made up out of the very thin air of opinion and personal experience. You might not always get a great outcome following the science, and you might sometimes getting one following the advice of unscientific media hype, but overall most of the time you’re better off with science informing your decisions.

    Of course, I can’t tell you what to do or what will help your cat, and these are the kinds of conversations you should ideally have with your vet.

    Good luck!

  27. v.t. says:

    @Barbara Kantrud Lerma,

    Curious why your vet chose a weight-loss diet (the Satiety formula) – unless you mean kitty has *recently* gained weight? Please understand that it is just as important that you focus on her thyroid therapy at this point and get it under control, where her diet may be more helpful at that point (the Satiety formula for example, might be helpful during this time and thereafter, or it may not, you have to discuss your concerns with your vet).

  28. Penny Howland says:

    Boy, I do wish I had found you before I pressed the “order” button on the “raw diet site”! I was feeling I wasn’t doing best I could. I should have listened to my voices telling me some things did not sound right! I’m supposed to be getting smarter, not dumber. I have 4 cats, 3 girls and a boy. Ha, I worry about their emotional and physical health! Really appreciate the sanity of this blog.

  29. skeptvet says:

    The arguments made for these diets can sound perfectly reasonable at first look, so don’t feel bad! Glad the information was helpful.

  30. Martyn says:

    Just read your blog about Dr. Marty and his raw food diet. I foolishly watched almost all of the infomercial but it all sounded too good to be true. I think I clicked away at the point where he tells us that the food will be available in small batches and to order soon.
    That didn’t make any business sense to me other than as a way of getting people to buy before the product sold out which screams scam very loudly to me.
    And whilst his point about big cats eating zebra on the Serengeti seemed logical,your point about them not being able to get anything else, (aside from gazelle and Cape buffalo I guess), made me laugh. Kind of obvious when you give it a seconds thought that you’d absolutely eat that thing if you were starving and had just run a marathon to kill it. Thanks for the good info. You’ve saved me money and made me go right back to feeling OK about what my partner and I are feeding Pretzel and Velvet.

  31. skeptvet says:

    Glad you found the article helpful!

  32. Marvin Von Renchler says:

    I almost fell for it too, just about to order then did a scam search. We have had all our dogs ( 8 of them) in the last 20 years die from cancer. Usually feeding them a brand of dry and another brand of canned. About five years ago started making our own out of ground turkey for humans, eggs, and rice. They had some skin problems but could be coincidence. Also supplemented with science diet dry. Then we switched rice to barley and they did a bit better, so we knocked out all grains and do ground boiled turkey, eggs, lentils, carrots and peas. We also use a science diet dry as filler and out vet said to do it. Our final two aussies are 13.5 years and aside from a bit stiff getting up, look 6 or 7 years old and are in perfect health. Coincidence? Oddly all out cats have died from cancer except a current 15 year old who ONLY eats dry kibble–cant get him to eat any human food including meat, fish, anything but bits of tuna once in a while but last year he was diagnosed as diabetic require daily injections.! Why? Why would a cat suddenly become diabetic? Processed food? Now he is on a major brand of dry for diabetic cats. Anything we can do? Should we worry abut our turkey/egg/veggies home made not being complete? Thanks SO much for the review on this subject. You saved us all time and money.

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