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The Case Against Raw Frozen Pet Foods

R. Wysong, DVM, V. Savant, PhD

For some 25 years Dr. Wysong has alerted the public to the dangers of exclusively feeding heat processed pet foods. Not only is nutrient value diminished by heat, but a spectrum of toxins are created. Additionally, the singular feeding of processed pet foods has led to the spurious "100% complete and balanced" claim that is both logically and scientifically flawed. Entrepreneurs have seized upon this information to create a spate of raw frozen (RF) pet foods to capture a market niche and to fill the demand from consumers wanting a raw alternative to standard heat processed canned, semi-moist and dried pet foods. This market trend, as with most others, may begin with some truth (raw food is the best food) but gets distorted, if not perverted, once economic opportunity enters the picture. This paper will examine the rationale of these pet products, their economics, and dangers. A more intelligent and healthy alternative will be proposed.

Dangers

Weakened Pets And Highly Virulent Organisms – A raw state and the presence of moisture in raw pet foods provide the perfect environment for the growth of pathogenic organisms. Although prey foods in the wild often putrefy and are teeming with microorganisms, carnivores in the wild are immunologically adapted to these organisms and even benefit from the probiotic effects of some. On the other hand, domestic pets eating sterilized heat processed foods are immunologically compromised and are threatened by mutated and highly virulent pathogenic strains created by modern circumstances and antibiotic resistance. Freezing at appropriate temperatures puts pathogens in a state of arrest but does not eliminate them. Although all foods contain some pathogens, unless they are sterilized (requiring high heat or other measures that greatly diminish the nutritional value and create toxins), it is the load of these pathogens that must be of concern to consumers. RF pet foods are a potential reservoir and vector of large numbers of pathogens.

Producers With Only Kitchen Technology – Because of the minimal technology required to produce a RF pet food, essentially anyone regardless of credentials or expertise can bring a product to market. All one needs to do is grind and mix ingredients in a kitchen, package and put in a freezer. There are no controls over the conditions in the kitchen, the quality of the ingredients or the method of freezing. All these factors can dramatically influence the nutritional value and pathogenic and toxic content of the food. But being in a frozen state hides these potential dangers and therefore poses a threat to both pets and the humans who handle the foods. John Doe can make a food under unknown conditions and with unknown ingredients, label, package, freeze and deliver to consumers or stores without one single control monitoring or impeding the process. Regulators may eventually examine the label if they happen to see it in a store (they will never see it if shipped directly to consumers) and may object to some terminology or the like; but, all John needs to do is change the label and all will be well. The product could contain every manner of ingredient, be laced with virulent pathogens, and receive the -- of regulators … and into the market it goes.

Raw Frozen Foods Are Not "100% Complete" – Many RF foods make (or imply) the same spurious 100% complete and balanced pet food claim as heat processed foods and thus carry with them the same health dangers. Feeding any food exclusively, let alone a nondescript packaged food containing who-knows-what from who-knows-what manufacturing environment is a bad choice if health and safety are of concern. (See The Truth About Pet Foods by Dr. Wysong).

Problems Are Ignored By Producers – RF food pathogens include not only bacteria, but fungi, viruses and parasites. Toxins include those from molds (mycotoxins), bacteria and those created by oxidation. In our study of RF pet products in the stream of commerce, not one producer addressed these concerns with any technological know-how that we could discern, and most did not even acknowledge the problems potentially lurking in their foods.

Freezing Masks Inedibles – Raw meat and organ tissue continues to use ATP (source of energy) until it is exhausted and the tissue enters a state of rigor. Endogenous enzymatic activity within the tissue continues to digest the muscle tissue (proteolysis) softening it until it becomes tender and develops the typical palatable taste. This process is retarded by cold. The freezing of properly aged meat presents few problems, however, any residual ATP present in the tissue during freezing will contract the muscle upon thawing resulting in a more unpalatable product. Mixed RF pet foods would hide this problem.

Free Radical Problems Masked – Essential fatty acids and other health enhancing lipids are critical in the diet. Once foods are ground, mixed, exposed to air, light and pro-oxidants such as heme iron and other metals found in plant and animal tissue, the contained lipids are oxidized to chain reaction producing free-radicals, causing rancidity and oxidant toxins. Freezing at appropriately low temperatures slows this process but does not stop it. The temperature in conventional freezers used for RF pet foods is not insurance against such oxidation. Because the frozen state masks olfactory detection of rancidity, foods that would be otherwise rejected end up being consumed. The free-radical pathology potential can then work its chronic degenerative disease and immune weakening effects.

Freezer Burn Indicates A More Serious Problem – Air reaching the meat surface is the cause for the freezer burns that result in the typical grayish-brown leathery spots. Frozen water on the surface or just beneath it sublimates (from solid state directly to vapor) into the air, causing moisture to be lost from the meat over time resulting in discoloration and a dry, leathery texture. Proper pet food packaging helps maintain quality and prevent freezer burn, however most packaging is permeable to air. The prevalence of freezer burn in RF pet products speaks to the fact that the product is being oxidized and with that creating free radical toxins to lay the seeds for various degenerative diseases.

Display Packaging Causes Free Radicals – Light, as well as air, can promote free radical production. Retail display pet packaging that is clear or light permeable permits light to catalyze the free radical (disease promoting) process.

Frozen Pet Products Are Not Inert To Degradation – In frozen storage there is deterioration in organoleptic quality – meat texture, fat turning granular and crumbly, and discoloration. Microbial enzymes also remain active, especially lipases that break down fats increasing their susceptibility to oxidation.

Frozen Pet Foods Can Lead To Acidemia – Tissue degradation and oxidation under high heat freezing (above 29° F), which occurs along the supply chain with RF pet products also leads to acidification. Increasing acid consumption can contribute to acidemia that lies at the base of virtually every chronic degenerative disease plaguing modern pets. (See references below.)

Temperature And Time Are Critical – Ice nucleation, as opposed to ice crystallization, is the primary vector in producing a stable, tasty, frozen pet product. Freezing is a technically complex process based on the optimum combination of temperature and time, amongst other factors. In the wrong processor's hands, slips in proper freezing care can lead to a microbiologically unstable product and/or a sensory inferior one. Rapid freezing leads to nucleation, thereby preventing undesirable large ice crystals from forming throughout the product. With rapid freezing the molecules don't have time to form positions in the characteristic six-sided snowflake, so nucleation overrides crystallization. On the other hand, slow freezing (the usual RF pet food situation) creates large ice crystals, which on thawing causes cellular damage to the meat. This in turn causes meat to "drip" – lose juiciness – and form a perfect liquid medium for bacterial growth.

The High Risk In Thawing – Thawing is another critical phase in the freezing process as it involves a change from crystal ice to melted water, which upon reabsorption results in microbial reactivation. Pathogenic bacteria inherently contaminate raw meat, fish, and poultry and will begin to multiply again when the temperature reaches just 29.3º F – which is below freezing! Thus a product that may appear subjectively frozen could be a veritable incubator of pathogens. When consumers attempt to thaw RF pe foods, dangers dramatically increase. The surface temperature rises long before the interior is sufficiently thawed to serve. For example, it takes about 15 hours for the middle of a 22-pound turkey to get to 32º F. In the interim the surface temperature rises to 53º F. In this amount of time there would be about 4 multiplications of spoilage bacteria as well as non-detectable multiplications of pathogens.

The FDA Model Food Code (1999) recommends that food be thawed in the refrigerator or in flowing water. Thawing RF food in the refrigerator can be inefficient and time consuming, in addition to occupying refrigeration space required for other food items. Most of all, this lengthy procedure can lead to the risk of cross-contamination when the drip from the raw meat comes in contact with ready-to-eat food stored in the refrigerator. In the alternative, consumers usually put the RF pet food out at room temperature, creating the perfect circumstance for pathogen proliferation.

Undetected Freeze-Thaw Cycles – The transit time of RF pet foods from the processor (or John Doe's kitchen) to the distributor, to the stores and eventually to the consumer is very critical. Although freezer delivery trucks might putatively maintain stable product temperatures, lack of thermocouples fitted in the truck to show temperature readings, and/or inadequate TTIs (time-temperature indicators) can lead to microbiologically infested products without any visible spoilage signs. If the refrigeration in any part of the supply chain fails temporarily and then goes back to frozen (freeze-thaw-freeze), the consumer would never know of this abuse and danger.

Supply Chain Time Dangers – Time is the enemy of nutrition and safety. The longer the time between the farmer's field and the belly, the greater the potential problems. RF pet foods create the illusion that time is not a factor. Because the frozen state masks toxins and odors, the consumer can be given the impression of value and freshness when, in fact, they may be getting age and toxicity.

Microwave Thawing Dangers – If RF pet foods are thawed in the microwave as a matter of convenience, the value of the food is greatly compromised. Microwaves can virtually boil the liquid phase within cells and electromagnetically alter important food components rendering them not only useless nutritionally, but toxic as well.

Mycotoxins Go Undetected – RF pet foods, particularly those that are a mix of cooked grains (which of course negates the claim for "rawness") and vegetables, can contain mycotoxins. None of the RF pet food producers surveyed addressed this problem.

Frozen Product Mixtures Make No Health Sense – In an attempt to cover every conceivable base and not miss any opportunity for profit, many RF pet food producers mix every manner of ingredient. For example, watermelon, grains, persimmons, liver, lamb, etc. Not only would creatures in the wild never eat such a smorgasbord gruel at one sitting, such combinations in the fresh state can cause serious digestive stress. Many of the exotic RF pet food ingredients do not keep well in the fresh frozen state (for example, freeze watermelon alone and see what happens, let alone combining it with meat). Also, the combination of fruit sugars with proteins can potentially create toxins such as glycation end products, acrylamides (particularly in those "RF" pet foods containing cooked carbohydrates) and reaction products of proteins with plant tannins, phenols and flavonoids. Producers "throwing the book" at RF pet food formulations in desperate attempts to capture market share make evident their motives and their scientific, health and technical naïveté.

Parasites Are Ignored – A wide range of parasites can be found within RF pet foods. Although there is technology in terms of freezing and natural ingredients that can be used to thwart this problem, none of the producers examined employed any of it that we could detect.

Packaging

The best packaging for any pet food, particularly RF pet foods, is light- and oxygen-barrier and modified atmosphere flushed. In the absence of this, oxidation proceeds rendering the lipids toxic. None of the producers surveyed employed these technologies that we could detect. Even if they did, the other problems and dangers listed above would remain.

Environmental

We live in an age of pollution and energy diminishment. RF pet foods require a tremendous amount of refrigeration and equipment all along the supply path. Freezing is energy inefficient and consumes valuable energy resources. Since RF pet foods are 70% water (at least) there are huge resources wasted in freezing and transporting the tons of this food-contained water through the supply chain. Along with all the equipment, trucking, freezing and frozen water handling inefficiency comes the pollution that parallels such industry.

Quality

In order to make their foods anywhere near affordable, RF pet food producers must search the ingredient market for items that can carry the name of real food but may in fact be only a hollow shell of the real thing. Inferior meat and organ ingredients, heat processed grains and vegetable riffraff (for example "broccoli" on a label may really be broccoli stems – like eating a branch from an apple tree rather than the apple) are used because they are of low cost. That is not to say the marketing brochures and labels do not make it appear as though the brand is not a true gourmet meal. If one reviews the various labels it becomes clear that the race is on to see who can put the fanciest and most exotic ingredients on labels ... as if that is the road to pet health. (It is not.) In a brief ingredient survey this is what we found:

Every manner of "pureed" vegetable Organic beef, rabbit, chicken, turkey, goat, lamb, duck, pork Organic honey Organic papaya, persimmons, blueberries, oranges, apples, pears Organic yogurt Organic alfalfa, millet, quinoa and barley sprouts Wheat grass Nettles Bok choy Cultured kefir Cod liver oil Capsicum Watermelon

The reader is challenged to go to the store and total up the cost of such ingredients. Some of the organic ingredients can cost over $15 per pound. But the RF pet diets containing them can retail for as little as $2-4 per pound. Take away margins for distributors and retail stores and the producer is selling them wholesale for close to a dollar per pound. Now on top of the cost of ingredients is the production, advertising, packaging, freezing and in some cases a sales force making six figures. Something most certainly does not add up. The only thing that can be missing is true ingredient quality. But how can the label say these expensive ingredients are in the food? All the RF pet food producer needs to do is put in pinches of the expensive ingredients just to say they are there.

The only economic hope for a RF pet food producer is to create the perception of "value added." They simply could not put the costly ingredients in the food to any degree and make a profit for themselves and all the middlemen up and down the chain. The price they would have to charge would be ridiculous. In effect, in order to be successful, producers must become accomplished at propaganda, not health and nutrition.

Consumers interested in cutting through to the truth do themselves and their pets a service by going to the grocery store with a list of the ingredients ostensibly in a RF pet diet. Although some RF diets in the lower price range appear to not be attempting to mislead, consumers should do the math comparing the exotic ingredients in RF pet foods to the prices for the real thing in the store and decide for themselves whether either value or honesty resides in RF pet products.

Economics

Consumers are under the mistaken assumption that a nondescript package mix of ingredients with an officious label and from a producer posing as a nutritional authority (none of the producers we examined had people at the helm with expertise or credentials) would be the best choice. Little do they realize that they could avoid essentially all of the caveats listed above by simply going to the grocer and buying fresh meats and produce. Pets do not require every nutrient in existence at every meal, as is the impression given by the 100% complete RF pet food producers, and for that matter the rest of the pet food industry. Why would people choose to pay a producer to mix inferior ingredients, package them, label them, freeze them, transport them, advertise them and pay the margin for the producer, the distributor, sales force and the retailer when they can avoid all that cost and put their money into real quality fresh foods? Some people are so convinced that RF pet food manufacturers perform some sort of magic that they will pay to have such foods put in special insulated containers packed with dry ice and overnight delivered! This is particularly ridiculous when one considers that no real convenience – and certainly no health or nutritional value – is added in the process. The consumer still has to go to the store and buy something.

At the grocer a person can buy fresh, raw, untainted meats and produce appropriate for pet carnivores at less than $1 per pound. Slightly out-of-date meats, sale items, trimmings or other still excellent products that cannot be put in the meat case can be even less. True, if you are to purchase the ingredients listed above in perfect human grade organic form (as many RF pet food producers boast) the cost could be far greater. But at least you would know what you are getting. RF pet foods can cost as much as $7 per pound with an average of about $3-4 per pound (not including shipping to the customer's door) and most of that cost is going into freezing, transportation and profits through a whole chain of participants. Here is a case where a consumer gets to pay more (a whole lot more) and get less (a whole lot less).

A Better Alternative

Fresh foods fed in variety are without question the perfect form of nutrition. Appropriately designed cat and dog supplements to help reduce the risk of food-borne pathogens and oxidation, and to help balance high meat meals and provide a spectrum of vegetable-based nutrients and nutraceuticals such as Wysong has developed can also be of great benefit. Anything less than this is a compromise. The next best alternative is packaged dried raw foods that have incorporated in them food technology to impede pathogens, parasites and oxidation. The low water activity of these products is a great inhibitor of pathogens and the low level of moisture make storage and shipping efficient and environmentally friendly. (See our Wysong TNT™ raw dog and cat foods .) Good quality table scraps and properly designed dry pet foods and canned pet foods can be mixed into the diet rotation with benefit as well.

Consumers must learn the principles of fresh foods fed in variety and to trust in nature. Every pet owner desires the best for their pet and they are correct in thinking food is an essential element in achieving that goal. But it is incorrect to believe that another person can do more for their pet's health than they can do themselves. All that is required is a little understanding and use of common sense. To that end we provide a free e-Health Letter, a free one-hour CD by Dr. Wysong entitled, "The Thinking Person's Master Key To Health," healthy product alternatives designed intelligently with health as the number one objective, and books and recipes for anyone wanting to take control of their own and their family's and pet's health destiny so as not be led down health destructive primrose marketing paths.

(Note: Although the authors are associated with the technical development of the Wysong products mentioned above, the reader should not misconstrue the information as a commercial inducement. Wysong will teach people for free how to fresh-food-feed using only products purchased in the meat and vegetable aisles in the grocery. Although Wysong products provide convenient and supplemental alternatives and variety, no Wysong product is required to be purchased in order to achieve this superior method of feeding. The position is taken at Wysong that health professionals [which we are] have an ethical responsibility to help people prevent disease and thus are duty bound to teach people how to not need their services. So that is exactly what we do. Wysong pet products are a mere tool to help people along that path to the ideal goal of health self-sufficiency.)

References: Cano-MuÃ±oz, G. (1991). Manual on meat cold store operation and management. FAO Animal Production And Health Paper 92. Food and Agriculture Organization of The United Nations, Rome. FDA Food Code (1999). U.S. Public Health Service, U.S. Dept. of Health and Human Services. Pub. No. PB99-115925. Washington, D.C. 20250 Food Safety and Inspection Service (2004). FOCUS ON: Freezing. U.S. Dept. of Agriculture. Washington,
D.C. 20250 Klose, A.A., Lineweaver, H., and Palmer, H.H. (1968). Thawing turkeys at ambient air temperature. Food Tech. 22:1310-1314.
Muldrew, K. and McGann, L.E. (1999). Cryobiology - A Short Course. http://www.ucalgary.ca/~kmuldrew/cryo_course/cryo_chap13_1.html
Snyder, O. P. (1999). Thawing At Ambient Temperature On The Counter. Hospitality Institute of Technology and Management, St. Paul, MN.
Wysong, R. L. (2004). Nutrition is a Serious Health Matter: The serious responsibility of manufacturing and selling. Wysong Institute, Midland, MI.
Wysong, R. L. (1990). Lipid Nutrition: Understanding Fats and Oils in Health and Disease. Midland, MI: Inquiry Press.
Wysong R. L. (1993). Rationale for Animal Nutrition. Midland, MI: Inquiry Press.
Wysong, R. L. (2000-2005). Wysong e-Health Letter. Wysong Institute, Midland, MI.
Wysong, R. L. (2002). The Truth About Pet Foods. Midland, MI: Inquiry Press.
Wysong, R. L. (2003, January 14). What to do to reverse and prevent acidemia. The Wysong e-Health Letter. Wysong Institute, Midland, MI.
Wysong, R. L. (2004). The Thinking Person's Master Key to Health (60 Minute CD Discussion). Wysong Institute, Midland, MI.

Sections of the above article have been rebutted by Steve's Real Food. That, and Wysong's response, follows.

Wysong Rebuttal to Steve's Real Food (SRF) Response

Dr. Wysong has previously published a critique of raw frozen pet foods and outlined their dangers. Here is that original article, followed by a response (SRF), and then, in bold, our rebuttal to that:

The Case AGAINST Raw Frozen Pet Foods–Dr. R. Wysong (the original article)

For some 25 years I have alerted the public to the dangers of exclusively feeding heat processed foods. Companion animal feeding has progressed - actually digressed - from table scraps and real foods the family could spare to today's "100 % complete" processed foods in primarily kibble form, with some canned and semi-moist also available. The foods appear to be scientific and improved, but they're far worse for the animals. Not only is nutrient value diminished by heat, but a spectrum of toxins is created. Additionally, the singular feeding of processed food has led to the spurious "100% complete and balanced" claim that is both logically and scientifically flawed.

SRF Response – For the last 25 years hasn't Dr Wysong has been selling heat processed dry food?? We agree that the labeling as complete and balanced according to AAFCO regulations is flawed because there is much more involved with nutritional content than simply measuring protein, fat and fiber content. We believe this because protein and caloric content can evolve from ingredients that are not from sources beneficial or readily bio-available to pets. Historically commercial pet foods have been developed from human food bi-products. This is why, up until recently, most pet food companies were owned by human cereal food processors like Nabisco, Standard Brands, Nestle, Ralston and many others. A smart guy said" why don't we run that waste back through the extruder and make a kibble for dogs to eat". Dogs wouldn't eat it because they didn't want to eat corn and wheat so they coated it with yellow grease, tallow and rendered digest and dogs ate it growing obese and loosing immune system properties. No wonder most all dogs life span started to shorten after WW2 when commercial dry and canned pet foods became popular.

We do not deny the apparent Wysong contradiction. We have long taught that if people follow Dr. Wysong's advice perfectly, they need not feed any commercial pet food–even Wysong's. However, our world is not ideal. People are not about to turn their pets loose into the wild to seek their most natural food. Nor are most people going to home prepare raw foods mimicking prey. Most are going to seek convenient packaged products. Thus, part of Wysong's activities is to produce the least compromised foods possible, including raw diets. Wysong does not just produce heat processed foods as SRF implies. In fact, it is Dr. Wysong who introduced the concept of raw food feeding to the pet food industryâ€¦and to SRF. Therefore, most of the arguments made in the SRF rebuttal do not apply to Wysong.

This rebuttal is not to suggest that processed pet foods are the ideal diet, it is to give balance and perspective regarding SRF's incorrect and exaggerated claims about pet foods other than theirs in order to promote their own commercial interests.

For example, pet foods other than theirs are not, as SRF claims, made of "waste" and "by-products," in the sense the public would normally interpret these terms: useless and harmful junk fit only for a toxic waste dump or land fill.

Most pet foods are comprised of highly nutritious ingredients and, although not "human grade," are far superior to most human foods. Humans would consider much of the natural diet of carnivores–the entire carcass of their prey–waste and by-product, yet this is the most healthful diet of all. White flour, white sugar, white salt, and white oils may seem pure, clean, and wholesome for human consumption, but they are nutrient impoverished. White flour and white rice with the by-product brans removed can create serious diseases that have killed thousands, such as Beri Beri. The "waste" bran had all the important nutrients and vitamins. Other discards from the human food industry can also be highly nutritious. For example, chicken by products–bones, organs, entrails, meat trimmings, digests–are far more nutritious than a "human grade" white chicken breast (or "human grade" twinkies, wieners, Fruit Loops, etc.), and a lot less costly too.

Pet foods other than SRF are not made of corn and wheat coated with "grease" and other unspeakables. Not only is this not true, as anyone can discern by reading the label of modern quality pet foods, but SRF's undocumented claim of decreased life span of pets since WW2 is untrue as well. Carnivores in the wild, given a sufficient supply of prey, have the most robust and long-lived health. That was not the state of pets prior to WW2. If anything, canning, baking, and extruding pet foods afforded most pets with a better opportunity for adequate (not to be confused with ideal) nutrition and longer life. Many people have used Wysong heat processed foods through generations of animals (contrary to our advice, but done because of ease and economy) and have had remarkable success with health (see testimonials).

Grains and food processing are, in fact, responsible for the burgeoning human population around the world. Although the best human diet is that which we could find in the wild, as the wild has run out, and agriculture (corn, wheat, etc.) took over, there has been an increased average life span. Although food abundance and heat processing is in large part responsible for this, such foods are, admittedly, not ideal. But neither are they the devil as SRF implies.

The reality of our world is that the grain food supply has taken population beyond the earth's natural carrying capacity. To sustain the present population of people and pets requires aggressive agriculture and prudent use of all food materials (including highly nutritious human food "waste" and "by-products") until a real solution for sustainability is found and enacted. Not only that, it is unethical and inhumane to raise animals for food and harvest only those parts that are cosmetically pleasing to us and discard the rest. It's like fishermen killing sharks, cutting off their fins for soup, and then throwing the body back in the ocean.

Expensive, high energy consuming SRF-type frozen pet foods made only of cosmetically sounding ingredients do not address these realities and ethical concerns.

Entrepreneurs have seized upon this information to create a spate of raw frozen (RF) foods to capture a market niche and to fill the demand from consumers wanting a raw alternative to standard heat processed canned, semi-moist and dried pet foods. This market trend, as with most others, may begin with some truth (raw food is the best food) but gets distorted, if not perverted, once economic opportunity enters the picture. This paper will examine the rationale of these products, their economics and dangers. A more intelligent and healthy alternative will be proposed.

Dangers

1. Weakened Pets And Highly Virulent Organisms - A raw state and the presence of moisture in food provide the perfect environment for the growth of pathogenic organisms. Although prey foods in the wild often putrefy and are teeming with microorganisms, carnivores in the wild are immunologically adapted to these organisms and even benefit from the probiotic effects of some. On the other hand, domestic pets eating sterilized heat processed foods are immunologically compromised and are threatened by mutated and highly virulent pathogenic strains created by modern circumstances and antibiotic resistance. Freezing at appropriate temperatures puts pathogens in a state of arrest but does not eliminate them. Although all foods contain some pathogens, unless they are sterilized (requiring high heat or other measures that greatly diminish the nutritional value and create toxins), it is the load of these pathogens that must be of concern to consumers. RF foods are a potential reservoir and vector of large numbers of pathogens.

SRF Response – To say that pets have evolved immune systems because of eating commercial sterile food for that last 40 years or so is preposterous. It take