Why We Do Not Use AAFCO For Raw?

Uncertainties in the AAFCO/NRC data

Unfortunately, there is not a great deal of good nutrition science in existence for either raw, or processed-fed pets. Most studies are small, and poorly designed, and industry sponsorship dominates. Wading through the NRC book you will find that the authors repeatedly warn us that the established requirements are a best guess based on a paucity of science. All too often people interpret the numbers in the NRC as ‘settled science,’ without considering the qualitative statements explaining how tenuous the science actually is.

So in the absence of reliable data from large controlled studies we are left with a combination of supportive data, evolutionary logic (one of the most important questions in science: “does this make sense?”), and clinical experience to decide how best to feed our pets. Clinical experience tells us that despite AAFCO compliant diets being the current dominant pet food: obesity, heart disease, skin disorders, diabetes, dental disease, renal disease and cancer are common occurrences. If our grasp of nutrition science was really good, vets and GPs would not be nearly so busy.

Take iodine as an example of the uncertainties. Although AAFCO generally follows NRC guidelines, they differ significantly in their iodine recommendations. The NRC states that:

“To our knowledge, however, there have been no detailed studies with cats to determine the range of daily iodine intake that is consistent with normal thyroid structure and function, particularly studies of iodine intake conducted over a long period of time…Until more data are accumulated concerning a possible relationship between levels of iodine intake and altered structure or function of the thyroid, it seems reasonable to recommend that pet food manufacturers should adjust the levels of iodine in their products to lie within the broad, albeit at present ill-defined, limits that have been recommended.” 1

Assessing the requirement for iodine is complicated. The NRC’s figures have been called into question:

“The recommended iodine intake across species appears to follow metabolic scaling for body weight (FIGURE 2). The recommended daily allowances for dogs and cats suggested by the National Research Council (NRC) in 2006 are in excess of NRC recommendations for other species, current AAFCO recommendations in cats, and earlier recommendations for dogs and cats based on metabolic body weight. The dietary iodine requirement in cats has recently been suggested to be closer to 0.46 ppm than to the 1.3 ppm reported by the NRC.10” 1

In 1970, recommendations fitted a metabolic scaling line along with other species. Today, cats and dogs are outliers.

The studies supporting the NRC iodine requirements had several flaws. Wedekind et al (2010)2 analysed the three studies and pointed out their weaknesses:

"The new NRC I [iodine] recommended allowances for the cat were based on three studies (Scott et al., 1961; Smith, 1996; Ranz et al., 2002) all of which failed to meet key criteria necessary for defining nutrient requirements. The Scott et al. (1961) study was never intended to be used as a requirement study; the diet used was an all meat diet (beef or sheep hearts) deficient in Ca, vitamin A and I and an imbalanced Ca:P ratio."

Focusing on single nutrients does not actually give us much information

Identifying a single nutrient requirement in isolation does not tell us how much of that nutrient an animal needs in real life. The nutrient does not exist in a vacuum. Its availability and action will be affected by multiple factors, including:

  • The form of the nutrient: Is it presented in a whole food form, or as an inorganic supplement?
  • Other ingested nutrients: For example high starch foods such as grains impair the absorption of minerals such as zinc.
  • The condition of the animal: An animal with chronic health issues, or on medication will absorb and utilise nutrients quite differently to a healthy, unmedicated animal.

Some examples of factors which affect nutrient absorption include:

  • Previous iodine intake affects the response of an individual cat or dog’s thyroid gland to future intakes.
  • “Reductions in the secretion of hydrochloric acid, gastric acid, and/or intrinsic factor, together with alterations in the permeability of the intestinal mucosa, are all examples of intestinal factors that can markedly influence the absorption of certain nutrients, but that are often ignored when setting dietary requirements.” 3 Omeprazole is a commonly prescribed drug in dogs which reduces acid secretions.
  • "Folates are produced by bacteria in the gut and are absorbed, but the contribution has not been quantified…the type of diet will affect the amount absorbed…The folic acid needs of dogs given diets based on natural constituents and not containing bacteriostatic agents [antibiotics, preservatives] may be partially met by microbial synthesis in the intestine…diets that are inadequate in choline... may increase requirements for folic acid." 4
  • "The quantity of vitamin E required in the diet depends on the rate of production of free radicals, the PUFA composition of membranes (a function of the diet), and other dietary compounds such as selenium" 4

Synthetic nutrients versus whole food nutrients - they are not the same

Two human nutrition science studies5 were pivotal in drawing attention to the difference between whole food and synthetic nutrients. Epidemiological (observational) studies identified a link between diets high in carotenoids (lots of fruit and vegetables), and high levels of serum ß-carotene with lower cancer incidence (particularly lung cancer). The correlation was particularly strong in lung cancer patients with a history of smoking. These findings led to the initiation of large controlled supplementation trials. The results were rather shocking:

  • The Alpha Tocopherol, Beta-carotene Cancer Prevention Trial (ATBC) revealed an increase in lung cancer risk in the treatment group - smokers who took the ß-carotene supplements.
  • The ß-carotene and Retinol Efficiency Trial (CARET) led to an increase in cancer among smokers and asbestos workers.

Both trials were halted before completion due to the increased death rates in the treatment groups.

More recently, evidence in pet nutrition has pointed to similar issues.

Renal (kidney) disease is common in dogs and cats. Survival time in patients with renal disease has been shown to improve when dietary phosphorus is reduced. The implication of this is that too much phosphorus is damaging to the kidneys. This led to the development of prescription renal diets (low in protein and phosphorus).

A recent paper in the British Journal of Nutrition (2019)6 made a rather astonishing finding regarding the difference between whole food phosphorus and supplementary phosphorus. The authors pointed out that “Phosphorus is present in diets as naturally occurring P from raw materials or added as an inorganic salt” but that little is known about how these two forms of phosphorus are absorbed in cats after ingestion. Using the data from several studies, the authors concluded that supplementary phosphorus led to an increase of phosphorus levels in the plasma, however phosphorus from whole food did not. So it is possible that the ubiquitous incidence of renal disease in pet cats is, at least in part, due to the presence of supplementary phosphorus which has been added to their processed diets in order to achieve AAFCO requirements.

Another paper in the British Journal of Nutrition (2018)7 adds weight to this idea. Key points in the paper are as follows:

  • “Renal disease has a high incidence in cats, and some evidence implicates dietary P as well...The bioavailability of dietary P is not only influenced by the P content of the diet, but the ratio of Ca:P and source of P have also been demonstrated to play important roles in absorption.”
  • Whole food versus supplementary forms of phosphorus affect plasma and urine levels of phosphorus differently: “Phosphates are widely used in commercial human and pet food manufacturing, where they serve a number of processing functions and as a source of required dietary P. Such P salts easily disassociate, solubilise and are readily absorbed in the intestinal tract; hence, P absorption can be greatly influenced by the chemical form ingested, with both circulating P concentration and urinary P excretion influenced by differences in dietary P availability.”
  • Supplementary phosphorus is considerably more bioavailable than whole food phosphorus, which suggests there is a greater risk for excessive phosphorus absorption on a processed diet: “Evidence suggests that over 90 % of inorganic P may be bioavailable, compared with between 40 and 60 % for naturally occurring sources.”
  • Supplementary phosphorus (compared to whole food phosphorus) may actually be harming the kidneys of healthy cats: “Our findings therefore support other reports indicating that diets including high levels of P from inorganic salts may have adverse effects on renal health in healthy cats.”

No doubt there is still much to learn about the difference between synthetic and whole food nutrients. What little we know so far is not yet accounted for in AAFCO recommendations.

If a pet food claims to meet AAFCO requirements - should we believe it?

AAFCO, despite its weaknesses, is currently the best option we have for processed foods. Or at least, it would be if consumers could be confident that packaging claims about AAFCO accreditation were true.

The Scientific Reports journal (2017) published a paper8 in which the authors analysed 177 widely available dog and cat foods to see if they complied with FEDIAF (the European version of AAFCO) guidelines for completeness. They discovered that only 8% of wet foods and 39% of dry foods complied. Pets were shown to be at risk from copper and selenium toxicity due to the high levels in some foods. The ratio of calcium to phosphorus (vital for proper bone growth) was wildly out in many products. A criticism levelled at raw feeding is that this ratio will be inappropriate. We have tested Raw Essentials products, and our ratio meets established requirements - which is unsurprising given that our diets are representative of the ratio in nature. 40% of the foods in the study had excessive ash levels, which is associated with renal disease. The authors suggested a link between the non-compliant foods and disease:

"A majority were non-compliant according to current European recommendations (FEDIAF, 2013). Many had either insufficient, excessive or an inappropriate balance of minerals which, if fed exclusively for a long period of time, could underpin a host of clinical diseases in dogs and cats including skeletal, neurological, or dermatological disease. Furthermore, foods with relatively high levels of fish or fish derivatives (i.e. ≥ 14%) also had high levels of undesirable metal elements such as arsenic, which bioaccumulate in internal organs and may contribute toward a plethora of subclinical disease"

In a New Zealand study9, Hendricks et al (1997) analysed 29 cat foods (ranging from budget to super premium) to see if their label claims of meeting AAFCO standards were true. 60% of the budget, 18% of the premium, and 43% of super premium cat foods failed to meet their stated AAFCO standards.

“The present study provides hitherto unavailable information on the nutrient composition of soft-moist cat foods sold in New Zealand, and indicates that a number of soft-moist cat foods cannot claim to be formulated to meet the nutrient profile of the Association of American Feed Control Officials.”

A study in the Journal of the American Veterinary Association (2014)10 found that 13.3% of canned cat foods from 45 different brands - all claiming to meet AAFCO standards - were below AAFCO for thiamine (and 15.6% were below NRC for thiamine), which has very serious implications for feline health. Four of these foods were manufactured in New Zealand.

The Journal of Animal Physiology and Animal Nutrition (2013) published a paper11 in which they analysed 12 hypoallergenic diets. These expensive diets are supposed to be free from allergenic proteins in order to relieve itching in pets. Ten of the twelve diets were contaminated with protein allergens not declared on the label. Another paper12 in the same journal found that four out of the four allergy diets they studied were contaminated.

The Australian Veterinary Journal published a paper (2016)13 by renowned New Zealand nutritionist, David Raubenheimer. The study analysed 10 wet and 10 dry ‘complete and balanced’ commercial cat foods, and compared the results with the labelling on the packages, and with established dietary requirements (AFFCO and NRC) for cats. The nutrient compositions and guaranteed analyses listed on the labels failed to match the chemical analyses carried out in the study. Deficiencies and excesses of various nutrients were found in nearly all the samples, many of which were identified as potentially harmful to cats ingesting the diets.

“The various nutrient deficiencies and excesses observed in a majority of the foods in this study highlight a serious issue in the nutritional composition of commercial cat foods in Australia. Both the nutrient composition and feeding guidelines require extensive review to ensure the adult cat’s unique dietary requirements are being met.”

In a 2004 study14 from the Archives of Veterinary Medicine 33 brands of dry dog food were analysed to see if they met AAFCO standards. Seven foods had an incorrect calcium:phosphorus ratio. There were inadequacies for potassium (13 foods), zinc (7), iodine (12) and selenium (1). Only 12% of the foods met the minimum requirements for protein, fats and minerals.

Additives in Pet foods

A range of additives are used to make food safe, stable, palatable, and convenient to handle and store. Long shelf lives are convenient for pet owners. But many of the additives used are controversial in terms of their effects on health. An article15 in Autoimmunity Reviews (2015) postulated

mechanisms by which food additives contribute to the rise in prevalence of

autoimmune conditions.

A paper16 in the Journal of Small Animal Practice (2021) reviewed the most common pet food additives, and found a number of concerning effects, for example: reductions in protein digestibility, potential carcinogenesis, haematological abnormalities, reduction in micronutrient availability, inflammation, and genotoxicity. Our raw diet contains no additives. It is inherently palatable. Safety and stability is maintained through proper storage and shorter shelf life.

AAFCO and Raw Essentials

AAFCO has been designed to ensure the presence of nutrients in processed petfoods within specified minimum and maximum limits. It assumes that these petfoods have been formulated from a selection of just over 1000 approved ingredients.

AAFCO may be the best option we currently have for processed foods, however it is important to recognise that it is a flawed system:

  • The recommendations are based on a paucity of science.
  • They do not take into account factors which affect nutrient absorption and utilisation - including the state of the animal, the effect of co-nutrients, and the form of the nutrients (whole food vs supplementary).
  • More often than not, processed pet foods fail to provide AAFCO compliant nutrients, despite claiming to do so on the label.

Raw Essentials does not formulate from ingredients. Rather, it is just species-appropriate food. The requirements for pets on a non-processed diet have not been fully defined by science, however enough is known to say that they are different from the requirements of a pet on a processed diet. Instead of AAFCO, we have a large body of supportive science, over a decade of clinical experience, and over 100,000 years of evolution to support the feeding of a carefully planned raw diet to cats and dogs.


  1. Zicker S, Schoenherr B. Focus on nutrition: the role of iodine in nutrition and metabolism. Compend Contin Educ Vet. 2012 Oct;34(10):E1-4. PMID: 23532759.
  2. Wedekind KJ, Blumer ME, Huntington CE, Spate V, Morris JS. The feline iodine requirement is lower than the 2006 NRC recommended allowance. J Anim Physiol Anim Nutr (Berl). 2010 Aug 1;94(4):527-39. doi: 10.1111/j.1439-0396.2009.00940.x. Epub 2009 Nov 11. PMID: 19906136.
  3. Gibson RS. The role of diet- and host-related factors in nutrient bioavailability and thus in nutrient-based dietary requirement estimates. Food Nutr Bull. 2007 Mar;28(1 Suppl International):S77-100. doi: 10.1177/15648265070281S108. PMID: 17521121.
  4. National Research Council. 2006. Nutrient Requirements of Dogs and Cats. Washington, DC: The National Academies Press. https://doi.org/10.17226/10668... J. Duffield-Lillico, Colin B. Begg, Reflections on the Landmark Studies of β-Carotene Supplementation, JNCI: Journal of the National Cancer Institute, Volume 96, Issue 23, 1 December 2004, Pages 1729–1731, https://doi.org/10.1093/jnci/d... JC, Staunton R, Colyer A, Thomas G, Gilham M, Logan DW, Butterwick R, Watson P. Not all forms of dietary phosphorus are equal: an evaluation of postprandial phosphorus concentrations in the plasma of the cat. Br J Nutr. 2019 Feb;121(3):270-284. doi: 10.1017/S0007114518003379. Epub 2018 Nov 13. PMID: 30420000; PMCID: PMC6390407.
  5. Alexander J, Stockman J, Atwal J, Butterwick R, Colyer A, Elliott D, Gilham M, Morris P, Staunton R, Renfrew H, Elliott J, Watson P. Effects of the long-term feeding of diets enriched with inorganic phosphorus on the adult feline kidney and phosphorus metabolism. Br J Nutr. 2018 Dec 21;121(3):1-21. doi: 10.1017/S0007114518002751. Epub ahead of print. PMID: 30572965; PMCID: PMC6390406.
  6. Davies, M., Alborough, R., Jones, L. et al. Mineral analysis of complete dog and cat foods in the UK and compliance with European guidelines. Sci Rep 7, 17107 (2017). https://doi.org/10.1038/s41598-017-17159-7
  7. Hendriks, WH; Tarttelin, MF, Nutrient composition of moist cat foods sold in New Zealand. Proceedings of the Nutrition Society of New Zealand (1997), 22:202-207
  8. Markovich JE, Freeman LM, Heinze CR. Analysis of thiamine concentrations in commercial canned foods formulated for cats. J Am Vet Med Assoc. 2014 Jan 15;244(2):175-9. doi: 10.2460/javma.244.2.175. PMID: 24378026.
  9. Ricci R, Granato A, Vascellari M, Boscarato M, Palagiano C, Andrighetto I, Diez M, Mutinelli F. Identification of undeclared sources of animal origin in canine dry foods used in dietary elimination trials. J Anim Physiol Anim Nutr (Berl). 2013 May;97 Suppl 1:32-8. doi: 10.1111/jpn.12045. PMID: 23639015.
  10. Raditic DM, Remillard RL, Tater KC. ELISA testing for common food antigens in four dry dog foods used in dietary elimination trials. J Anim Physiol Anim Nutr (Berl). 2011 Feb;95(1):90-7. doi: 10.1111/j.1439-0396.2010.01016.x. Epub 2010 Oct 29. PMID: 21039924.
  11. Gosper EC, Raubenheimer D, Machovsky-Capuska GE, Chaves AV. Discrepancy between the composition of some commercial cat foods and their package labelling and suitability for meeting nutritional requirements. Aust Vet J. 2016 Jan-Feb;94(1-2):12-7. doi: 10.1111/avj.12397. Epub 2016 Jan 14. PMID: 26763535.
  12. Hodgkinson, S. M., Rosales, C. E., Alomar, D., & Boroschek, D.. (2004). Evaluación químico-nutricional de alimentos secos comerciales en Chile para perros adultos en mantención. Archivos de medicina veterinaria, 36(2), 173-181. https://dx.doi.org/10.4067/S0301-732X2004000200008
  13. Lerner A, Matthias T. Changes in intestinal tight junction permeability associated with industrial food additives explain the rising incidence of autoimmune disease. Autoimmun Rev. 2015 Jun;14(6):479-89. doi: 10.1016/j.autrev.2015.01.009. Epub 2015 Feb 9. PMID: 25676324.
  14. Craig, J.M., Additives in pet food: are they safe? J Small Anim Pract (2021), 1–12 https://doi.org/10.1111/jsap.13375


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