Updated: Oct 15, 2021
“Natural” diets have become all the craze with consumer awareness about healthier eating and better nutrition for ourselves and our animal family members. Pet food companies are picking up on this and creating new lines of “natural” dog foods all the time. But what they call “natural” and what you would consider “natural” are probably not aligned based on the AAFCO regulations, at least if you live in the United States of America.
Additionally, many of these “natural” foods are a far cry from the “Natural Feeding” which is the focus of this article. First we are going to take a look at the requirements to label a food “natural”. Then we are going to take a closer look at the fresh food feeding approaches called “Instinctual” and “Ancestral” feeding, what these mean, and some information about the effect of these feeding approaches on the physiology of dogs and cats compared to feeding processed commercial foods.
So, if you're interested in some science behind feeding for well-being, this post is for you.
Intention Setting: Metta Pets Style
Anyone that knows me well, as a human beyond my "veterinary oncologist" label, knows that I always try to lead any new endeavor, any class I am facilitating and any important conversation by setting a clear intention and heart space. It is this clear intention that allows us to move forward with clarity, kindness and compassion and toward new understandings in a world that is largely chaotic and populated with many differing life experiences, opinions and belief systems.
We are going to explore Natural Feeding from the starting point that every pet parent and every veterinarian is currently doing what they genuinely believe to be right based on their belief system, training, social conditioning and current understanding. Because I do truly believe this to be true. From that starting point we are going to embark on a journey of curiosity. Of answer seeking. Because a scientific mind is a curious mind. And a curious mind is always asking questions, seeking to evolve its current beliefs and worldviews. And a compassionate heart is always looking to help others more effectively, whether they be two-legged or four.
Now, on with the Science....
We are going to explore some science behind Natural Feeding by reviewing a 2014 article published in the Journal of Animal Science called "Natural Pet Food: a review of natural diets and their impact on canine and feline physiology." If you are so inclined, you can access the article here.
Balance and Perspective
One more thing before we start... It is accurate (although sometimes uncomfortable) to remember that our scientific understanding of healing and supporting optimal well-being is still evolving. While we have made huge strides in our approach to wellness, our understanding is still incomplete. This is true of every field in western biomedicine, human and animal, including nutrition and my field of oncology. When we understand and believe that we don't have all the answers yet, we are better positioned to find them. This is the heart of a true scientist...curiosity.
Medicine is a landscape that consists of strong opinions from intelligent and highly educated people, which can be conflicting. This creates a fertile opportunity for positive growth if we are willing to engage in interesting and respectful discussions. To acknowledge what has been effective while continuing to ask questions about how to be better. Formulating better questions is key to the success of scientific inquiry. This truth highlights the need for mutual respect, kindness and objectivity when engaging in these discussions with each other.
Thinking outside the box
I like this quote by Albert Einstein: "We can't solve problems by using the same kind of thinking we used when we created them." At the heart of this blog today is my desire to find better answers for cancer patients, to ask questions where my 18 years of clinical oncology experience is not supporting my previous views or what I was taught in my veterinary school training. Until we are curing every cancer, or we stop getting cancer in the first place, there are pieces to the puzzle that we are missing. Finding these missing pieces necessitates thinking outside the box and considering other factors we haven't previously accepted as being important. Science is beginning to make our box a little bigger, and work is always being done to gain understand about other ways of thinking. That's what this blog is about.
Here's to us identifying a more effective path to optimal well-being, and being kind to each other while we are on that journey together.
*Note: reference links, when available, can be found by hovering over underlined text. Additional references at the end of the article. I've done my best to include a balanced representation of relevant information from this article. The information here, other than my obvious commentary, is from the scientific review article cited above. For expounded information I recommend reading that article directly.
“Natural diets, including instinctual or ancestral diets, are based on feeding pets according to their physiological capabilities or preferences, rather than simply meeting the regulatory definition of a natural pet food product.” - Journal of Animal Science, 2014
What does “Natural” on a dog food package really mean?
It is important for pet parents in the United States to understand that the term “natural” on a pet food bag does not mean it is a "Natural Diet". The regulations on using the label "natural" on a dog food primarily refer to ingredient processing, and only to the degree that synthetic and chemical methods cannot be used to produce or process the ingredients. AAFCO (The Association of American Feed Control Officials) does nothing to regulate processing beyond this definition and only requires that parts of whole foods (not actual whole foods) without synthetic additives be used. Additionally, nutrient profile and use of genetically modified ingredients are not addressed.
As a point of contrast, in Europe whole non-GMO ingredients are the only food stuffs allowed to comprise “natural” pet foods (European Pet Food Industry Federation; FEDIAF). Additionally, these ingredients cannot have been subjected to any processing that changes the nutrient profile of the whole food. Notably, rendering and heat processing, common practices in the U.S. pet food industry, are not allowed.
“The inclusion of whole food ingredients in natural pet foods as opposed to fractionated ingredients may result in higher nutrient concentrations, including phytonutrients. Additionally, the processing of commercial pet food can impact digestibility, nutrient bioavailability, and safety, which are particularly important considerations with new product formats in the natural pet food category.” - Journal of Animal Science, 2014
Despite some claims I have heard to the contrary, there are studies evaluating fresh food feeding in dogs and cats. Additionally, much of the information guiding current choices and nutrient profile for processed pet food are not made based on whether the nutrient profile and processing provides ideal nutrition for dogs and cats, but heavily weighted toward economic and environmental considerations and the justification that certain nutrient profiles, which fit these agendas, have not been proven to be detrimental in a clinical trial setting. This is not the same as being nutritionally ideal.
You Have Power
This is an important fact to keep in mind when integrating the vast array of information going around about the nutrient content of pet foods. It is important to know that you have choices. And that your choices matter!
understanding is power in feeding for well-being and healing
Most commercial pet foods have a very high percentage of carbohydrates compared to what may be physiologically and metabolically ideal, based on information later in this article.
The way raw ingredients are processed makes a difference in ultimate nutritional bioavailability and biological activity in your pet's body.
High quality ingredients and minimal processing cost more.
The Great News!
You have choices.
Pet food manufacturers pay attention to your choices.
This is your power as a pet parent and conscious consumer.
If we are interested in feeding for well-being, we need to look deeper and ask respectful questions. And we must do this with a mindset of empowerment. Because, remember, these foods exist because people buy them. And they persist because people choose cost over content. So, as a conscious consumer and pet parent, you have power to help change the pet food industry's approach to diet formulation. And you have power to help your pet live a healthier more vibrant life, no matter what stage of life they may be in right now. That matters!
So, as we embark on our journey of educating ourselves on "alternative" feeding, we must understand the basic truths about what we do and don’t understand about optimal nutrition based on published research. In other words, we must differentiate what has and has not been scientifically evaluated yet from what is and is not nutritionally important.
Does a “balanced diet” mean physiologically ideal?
Despite many advances in the field of veterinary nutrition, standard “balanced” food recommendations and their significant benefit to companion animal health to date, our understanding of optimal nutrition, especially for cancer patients, with a focus on wellness and thriving (not just staying alive) is still developing. A perfect example of this is the conflicting opinions among experts on the optimal vitamin D level in companion animals, both to obtain optimal health and to potentially treat certain disease conditions. Vitamin D blood levels in companion dogs and cats eating a nutritionally balanced commercial diet based on AAFCO regulations vary widely and the previously held baseline vitamin D level may not be ideal for preventing disease. This same learning objective is a huge focus on human medicine now as well. We now know that many diseases are related to low vitamin D levels. This clearly illustrates that, even just in this one area, there is a need for the evolution of our current understanding of feeding our canine and feline companions.
If we are paying attention to the epidemic of chronic disease in companion animals being fed "complete and balanced scientifically validated" commercial diets, we must admit that any logical, scientific, and rational mind would wonder what pieces of the picture we are missing. And, in that curious state of mind, allow our beliefs about diet to evolve beyond what we have been told in the past. To me, this was the vital question that prompted me to think beyond what I was taught in veterinary school:
In light of the current epidemics of cancer, degenerative disease and obesity/metabolic syndrome in both people and pets,
what actually constitutes a diet that feeds for
well-being, disease prevention and healing?
With this goal, a curious and intelligent mind, kindness and compassion for where we have all come from and where we can support each other in evolving our understanding, let’s take a look at some of the research on Instinctual and Ancestral feeding versus Commercial processed diets.
Natural Feeding Definitions
Instinctual and Ancestral feeding philosophies are "Natural Feeding" approaches based on feeding for well-being, meaning feeding for ideal physiological and metabolic health. Both approaches contain more protein and less carbohydrates than most dry pet foods.
This approach feeds animals based on their innate preferences with the belief that pets will self-select the nutrients they need. Macronutrient balancing is known to be a primary driver for foraging in herbivores, omnivores, and carnivores. This finding has also been supported for cats and dogs.
A number of studies have evaluated the macronutrient profile of the innate diet preferences of dogs and cats. In a study by Hewson-Hughes et al in 2013, dogs of various breeds selected a macronutrient profile of 30% protein, 63% fat, 7% carbohydrates. Dogs appear to find fats highly palatable and healthy dogs have minimal adverse health events associated with high fat diets. This is particularly interesting in light of the current conventional thought that fats are bad for dogs and lead to development of pancreatitis.
Fats: Looking Deeper
We might consider this singular observation about fats, for example, based on our experience of pancreatitis in dogs after eating high-heat altered or rancid fats such as those found in processed dog foods and highly processed and cooked human meat foods like bacon and fast food hamburgers. The adverse events associated with ingestion of these fats usually occurs while dogs are eating a daily diet markedly higher in carbohydrates (40-50%) than what would naturally be selected for based on the research cited above. I can't tell you the number of patients who have ended up hospitalized after well-intentioned pet parents have "treated" them to a McDonald's hamburger. So this issue is real. But if we engage our curious mind and look deeper, we might ask the questions:
"How does heat processing alter the biological activity of fats in the body?" and
"Is there a biological reason pancreatitis develops with fat ingestion that is related to chronic consumption of a high carbohydrate diet and/or the metabolic shifts that occur when eating a diet that is much higher in carbohydrates than would be naturally selected?"
Cats select for a macronutrient profile of 52% protein, 36% fat, 12% carbohydrate. A separate 2017 study corroborated this finding showing that cats fed canned food options regulate their macronutrient intake to attain a macronutrient profile of 53% protein, 36% fat and 11% carbohydrate. Interestingly, it was also documented that when this profile is unattainable, cats have a ceiling for carbohydrate consumption that will limit food intake and cause them to assume deficits in their protein and fat intake relative to these ideal ratios rather than over-consume carbohydrates. The ability to select for foods to balance this macronutrient profile was not affected by moisture or texture of the foods provided. Additionally, a 2016 study by Hewson-Hughes et al evaluated the impact of taste and smell on foods chosen by cats. It showed that selection is based on balancing protein and fat content and is independent of taste and smell. So, our stubborn kitties may be stubborn for a very good reason. They may be trying to tell us something.
This approach feeds pets based on the diet of their evolutionary ancestors with the belief that this will be more biologically appropriate to meet physiological needs and metabolic capacities.
Domestic dogs evolved from wolves. Wolves consume diets that are 52% protein, 47% fat, 1% carbohydrate and primarily consist of large game. This information comes from an analysis of 50 diets consumed by wolves. [reference: Hendriks, W.H. 2013. The Nature of canine and feline nutrition. In: the WALTHAM International Nutritional Sciences Symposium, Portland, OR. p. 21-22]. Feral dogs and jackals consume a wide variety of foods based on what is readily available in their environment, such as fruits, berries, grass, small prey. The conclusion is that dogs are highly adaptable omnivores based on what is available with minimal energy expenditure. There is research suggesting close human contact has led to genetic shifts which have increased the capacity for starch digestion in domestic dogs compared to their wolf ancestors. This ability to tolerate and digest higher amounts of carbohydrate is one of the arguments for supporting inclusion of grains and higher starch content in commercial dogs foods. However, this capacity to digest carbohydrates does not provide scientific information on the health effects of this kind of feeding on well-being, diet-related longevity or the physiology and metabolic health of dogs.
My Curious Mind Says:
I can eat ice cream, potato chips, and hot dogs. I can not die, at least not immediately or noticeably, when I eat a diet of completely processed packaged food and a good multivitamin. Does that mean it supports optimal physiological and metabolic function? Does that mean these foods are part of a nutritionally ideal diet that supports my healing and well-being? Of course not! This is how my mind works when I read the literature on food ingredients for dogs and cats...and humans.
I ask these questions because I have had to take a closer look at my own diet. The significant stress of Veterinary School and Residency training took a significant toll on my body's ability to thrive. It is common knowledge that stress creates a situation where the body is less able to adapt to suboptimal nutrition. Stress on the body can come in many forms: environmental, physical, emotional, illness, chronic sub-optimal nutrition....cancer.
I have personally experienced the transformative effects of eating a cleaner diet focused on well-being and thriving. I have experienced how this results in significantly improved energy levels and capacity for my body to heal and thrive.
I have, likewise, experienced the happy surprise of countless pet parents who report the same notable effects in their beloved pets when switched to a cleaner, less processed, lower carbohydrate diet.
Experience is one type of evidence.
It is this experience that inspires and informs new research and new understanding, that fuels new hypothesis and engages curious minds. That causes us to ask important and interesting questions. That brings us to new levels of understanding and well-being.
So, I’m wondering, how curious are we?
Analysis of mitochondrial DNA has shown that domestic cats are most closely related to the European wildcat, African wildcat and the sand cat. Behaviors are conserved between these groups. Feral cats have been shown to consume a diet that is 52% protein, 46% fat, 2% carbohydrates, consisting of mostly small mammals, birds, fish, reptiles and bugs. Interestingly, the actual macronutrient content of these typical feral cat prey animals has been shown to have a higher protein and lower fat ratio of 62% protein, 11% fat and 13% carbohydrates (calculated value based on 100% - 62% protein - 11% fat - 14% ash reported in the article). This natural prey also has a moisture content of 67% according to this same study. One might wonder, then, if even cats in the wild are selecting for a certain macronutrient profile rather than just consuming the entirety of the prey they hunt.
Domestic cats, unlike dogs, have retained the dietary preferences and digestive function of their wild counterparts based on comparison of macronutrient digestibility between various captive exotic felids. This truth is also reflected in the fact that, for cats, the macronutrient profiles for Instinctual and Ancestral eating are very similar. The information cited in these articles it would suggest that diets much lower and carbohydrates and higher in protein than most commercially available dry foods, which tend to be around 40-55% carbohydrates, may be more appropriate for cats.
Physiological and Metabolic Considerations
While it has been shown that cats have the enzymatic ability to digest carbohydrates in their diet, it has also been reported that cats can develop digestive disorders when fed high amounts of carbohydrates. Numerous studies have been conducted evaluating the impact of various macronutrient profiles in cats and their effect on insulin sensitivity. There is evidence to support carbohydrate restriction in cats. One example, a 2002 study by Farrow et al reports: "High‐ and Moderate-carbohydrate diets increase postprandial glycemia (post-meal blood sugar) in healthy cats compared with diets high in fat or protein... Avoidance of high‐ and moderate‐carbohydrate diets can be advantageous in cats at risk of diabetes." Contradicting this report, another showed insulin resistance was seen with home-made low (7%) carbohydrate diets. Furthermore, it has been shown that high fat content reduces metabolic tolerance of glucose (carbohydrates) in cats. This suggests the complex metabolic processes at play in this carnivorous species and the sometimes conflicting nature of the scientific studies illuminating our ongoing process of identifying optimal feeding approaches and nutritional nuances for certain disease states.
Dogs generate twice the amount of energy from fat oxidation relative to humans. This means they are naturally equipped to very efficiently use fats as a fuel source. Numerous studies have shown, however, that dogs have responses to carbohydrates similar to humans, in that higher carbohydrate diets result in higher spikes in post-prandial blood glucose. We have already seen based on some of the evidence in cats about why high carbohydrate and high fat in combination may be metabolically problematic. The Journal of Natural Science article referenced here also outlines numerous studies showing that higher protein and fat improved exercise performance and aided weight loss in dogs as well as some additional information in cats, for those interested in additional details. To summarize all the research articles here would be another article entirely, or even a book!
Studies exist that support that
the macronutrient profiles of Instinctual Nutrition may be more ideal for canine and feline physiologic and metabolic capacities,
especially when under stress when optimal nutrient range is more narrow, such as illness, growth or athletic training.
Interesting fact: macronutrient profile of the Instinctual Diet for dogs is almost identical to the Phase 1 ketogenic diet for health maintenance.
Canine Instinctual Diet:
63% fat, 30% protein, 7% carbohydrates
69% fat, 30% protein, 1% carbohydrate
The preferred macronutrient profiles of Instinctual Feeding are substantially different from NRC recommended allowances and minimal requirements (NRC, 2006. Nutrient requirements of dogs and cats. The National Academies Press, Washington, DC.) This, along with the studies evaluating digestive physiology and carbohydrate metabolism, suggest that additional research is warranted to continue to improve our understanding of optimal macronutrient ratios in dogs and cats and evolve standards in veterinary nutritional recommendations.
Commercial Dog Food: What you want to know about Ingredients, Processing & Effects on Nutrition
The argument often stated for continued higher carbohydrate food content is that dogs and cats, when in a state of health or "maintenance", can use a broader range of nutrient profiles than the instinctual or ancestral diet. These carbohydrate food ingredients provide for a more sustainable pet food industry, because more economically costly and environmentally taxing meat and fat sources are minimized. The competition for human grade meats and other human food ingredients is another reason for the ingredient selection in pet foods (this is outlined in Advanced Nutrition: Nutritional Sustainability of Pet Foods by Swanson, Carter, et al). These facts bring to light why commercial pet foods may chose ingredients to optimize economic and environmental considerations, accepting sub-optimal nutritional profiles, and how these issues influence the ingredient formulation of pet diets.
Understanding Standards in Commercial Food Processing
Each step in food processing impacts the "naturalness" and nutritional bioactivity of the final product. This starts with crop and livestock production and ends with ingredient processing, preservation, extrusion and canning. To really understand the nutritional impact of a food, a thorough understanding of ingredient production, preparation, processing and preservation is necessary.
The US regulatory organization, AAFCO, allows the following processing approaches in "natural" food ingredients: physical processing, heat processing, rendering, purification, extraction, hydrolysis, enzymolysis and fermentation. Lets take a closer look at the impact of rendering and heat processing, in particular, on food quality. In Europe, these processing practices are not allowed for "natural" labeled foods because they change the natural composition of the food.
The definition of “natural” pet feed varies between countries
In the US, the definition of “natural” according to AAFCO is:
“...A feed or ingredient derived solely from plant, animal or mined sources, either in its unprocessed state or having been subject to physical processing, heat processing, rendering, purification, extraction, hydrolysis, enzymolysis or fermentation, but not having been produced by or subject to a chemically synthetic process and not containing any additives or processing aids that are chemically synthetic except in amounts as might occur unavoidably in good manufacturing practices. (AAFCO, 2013)”
According to The European Pet Food Industry Federation (FEDIAF):
“The term “natural” should be used only to describe pet food components (derived from plant, animal, microorganism or minerals) to which nothing has been added and which have been subjected only to such physical processing as to make them suitable for pet food production and maintaining the natural composition. (FEDIAF, 2011)… Processing of components including freezing, concentration, extraction (without chemicals), drying, pasteurization, or smoking (without chemicals) is acceptable as far as it maintains the natural composition. Microbiological and enzymatic processes, hydrolysis, or natural fermentation processes (without the use of genetically modified organisms) are acceptable with the use of the term natural (FEDIAF, 2011).”
The Nutritional Impact of Rendering Meats
Rendering is a process that separates waste animal tissues that are not fit for human consumption into fat and bone/protein, yielding grease and various “meals” - meat meal, bone meal, protein meal, poultry by-product meal. This process is important when considering the health benefits of whole food ingredients versus parts. It is also important in understanding the starting quality of the "meat stuff" in many commercial pet foods.
There is a big difference between raw animal products and rendered products. The nutritional value of rendered animal products has been shown to be highly variable and dependent on the way the products are processed and what "by-products" are included in the rendered animal material. Feed-grade poultry by-product meal, for example, includes feathers and heads. The nutrient quality of this type of "feed-grade" rendered chicken is much less consistent than "pet-food-grade" poultry by-product that does not include feathers and heads. Rendered poultry products are also known to be less digestible compared to raw animal products. Additionally, these issues in nutrient variability are highly impacted by supplier handling, processing and preservation.
The Nutritional Impact of Heat Processing
Heat processing has been shown to significantly decrease digestibility of food matter in a number of recent studies. High heat processing used to make canned foods has been shown to decreases amino acid digestibility. For dry foods - these are called "extruded" foods because the ingredients are subjected to heat and then forced through a mold to form a kibble shape - standard high heat processing (over 392F) used to make these foods decreases nutrient content compared to using lower heat (under 320F). For example, this study showed a decrease in lysine, linoleic acid and linolenic acid with high heat processing of dog food. In yet another study, digestibility of dry kibble cat food was compared to digestibility of both raw beef and cooked beef diets. This study showed that digestibility was significantly less for the extruded food compared to the raw beef and cooked beef diets, which were equally digestible.
Heat processing also decreased the moisture content of the food. If following a philosophy of "Natural Feeding" a moisture content similar to animal prey would be in alignment with the nutritional aspects of Natural Feeding. As mentioned previously, one study showed that feral Cats in California consumed prey that are 67% water. In domesticated cats, moisture content of the diet has been shown to impact health. For example, high moisture foods (over 73%) were shown to decrease urinary tract disease in cats. This is a significant consideration given the widespread incidence of urinary tract disease in domestic cats which not only affects quality of life, but also often results in euthanasia.
High heat processing not only decreases nutrient quality in pet foods, but it also results in production of certain carcinogens such as Acrylamide (from Carbohydrates) and Heterocyclic amines (from meats). This is a huge topic in itself, which also has important implications in human health. I do talk a little about Acrylamides in a previous blog on grains in processed foods. This is a topic we will further explore together later.
The Importance of Whole Foods
Food synergy is a concept based on the idea that the entire composition of naturally occurring food components within a food type have a biological activity that is different from the individual food components on their own. The basis of this philosophy is that our understanding of the complexities of food composition and its effects on health are incomplete. Because of this, nutritional recommendations based on individual nutritional components, as is the standard of our nutritional approach in veterinary medicine at this time, may result in undervaluing or excluding as of yet unidentified nutritional components from foods which may have a beneficial impact on health. Applying this concept to veterinary diets is not that far a stretch considering what is being discovered about the value of whole food nutrition in humans.
A number of studies in human medicine have proven this concept of food synergy to be true. And we know that this applies to the biological effects of herbal medicines and spices. There are even some studies in rodents that show food synergy from fruits had positive effects on antiproliferative and anticarcinogenic processes. Another study showed that feeding a whole apple was more effective at protecting from mammary cancer in rats than feeding the apple flesh without the skin.
Safe Handling of Raw Meat Diets
This is also a lengthy topic when exploring the true zoonotic risk of dogs passing on bacteria from their feces to humans. In short, pasteurization of raw animal products in raw diets, or thorough microbiological testing, can help decrease incidence of bacteria shedding in the stool of raw fed pets. Also, application of common sense safe food handling practices will contribute to lower risk of this particular issue if you do choose to feed raw food. Although all the studies I am aware of that have been done to date, actual transmission of pathologic bacteria to people from pet dogs has not been documented, it is wise to exercise caution. Additionally, I don't normally recommend raw diets in my patients receiving chemotherapy due to the alternations in the gut which occur with chemotherapy and the possibility that this might potentially increase risk of clinically relevant infection if bacterial contamination of the food is present. (This is a logical concern that has not been scientifically proven to be true in dogs and cats, yet it makes sense to me to be cautious in this situation based on what I understand about the adverse effects of chemotherapy on gut integrity.)
If you are preparing raw meat diets, safe food handling practices are important to prevent food-borne illness. Use stainless steel or glass bowls and food preparation surfaces that can be sterilized after each meal. Handle all raw meats using the same common sense safety measures you use when preparing raw chicken or hamburger for your human family. Wash hands and all food preparation surfaces to disinfect before and after handing raw meat. Use the freshest meats possible and do not allow the meat to stay unused in the refrigerator for an extended period of time. Freezing meats can also decrease risk of certain food-borne parasites. If immune compromised people or young children live in the household, there is theoretically an increased risk of transmission of bacteria and cooked diets may be preferable in these situations.
These studies illustrate the many opportunities we have to further investigate Natural Feeding in order to better understand the impact of these feeding approaches on nutrient bioavailability, physiology, metabolism and disease prevention.
We can see from this brief overview of the published research from only one published review article that claims that no research exists evaluating Natural Feeding approaches for dogs and cats are simply inaccurate. Natural Feeding, however, is not the same as throwing a bunch of fresh food in a bowl. There is a method to doing this too in a way that supports optimal physiological and metabolic health. Our understanding in this area is growing. The bottom line is that nature is smart. Whole foods provide comprehensive nutritional effects in the body that we are only now beginning to appreciate in the scientific field, both on the human and animal side.
Change takes effort. Furthermore, changing foundational beliefs is uncomfortable, threatening and scary for most people, as it challenges the solid ground on which we have built our current approach to life. And our understanding of optimal nutrition is always evolving. For these reasons, to facilitate effective change, kindness and understanding is imperative when communicating with each other about these kinds of topics. And the best approach forward is always one in which we take personal responsibility for what is in our power to control. That means we use the power of our choices and our own intellect. And as we respect where others are on their own path to better understanding, to the best of our current understanding and capacity, we focus on what we can do as individuals to make a positive impact in the lives of our pets, and in the world in general.
As always, I recommend working closely with your veterinarian when making major changes to your pet's diet. Transitioning a pet onto a diet with a significantly different macronutrient ratio than they are accustomed to takes care and understanding about how to do that safely. If you want to learn more about ketogenic feeding in dogs (remember the canine Instinctual Diet is almost identical to the Phase 1 ketogenic diet, which is the maintenance phase) you can read the ins and outs about it here. Just like people, there is not one specific diet that is ideal for every pet and every situation. Especially if your pet has an acute or chronic ongoing medical condition, disease-specific therapeutic dietary approaches may be most appropriate. For example, for pets that require a low fat diet for whom more natural feeding is desire, there are fresh food options that provide a low fat, low carbohydrate diet that are not subjected to high heat processing. Additionally, there are now some options for unprocessed diets for kidney disease as well.
The most important factor in developing or altering a feeding program for your pet is to have respectful communication with your veterinarian so that your goals and your pet's needs can both be factored into an effective treatment approach. Creating a strong team that is working together for your pet's well-being is a vital and rewarding experience when embarked upon with mutual respect, compassion and open communication. Additionally, there are many factors that go into the choices you ultimately make for your pet's feeding regimen including lifestyle, finances and medical conditions. If the world were black-and-white it would be easy. Instead, it's interesting :)
To Sum It Up
Instinctual Feeding: the macronutrient profile that pets instinctually consume when allowed to freely choose their macronutrient ratios
Dogs: 30% protein, 63% fat, 7% carbohydrates
Cats: 52% protein, 36% fat, 12% carbohydrates
Ancestral Feeding: the macronutrient ratios that mimic the diets of their non-domesticated counterparts in the wild
Wolves: 52% protein, 47% fat, 1% carbohydrate
Feral Cats: 52% protein, 46% fat, 2% carbohydrates
Most dry kibble diets are 40-55% carbohydrates
The Instinctual Canine Diet macronutrient profile is almost identical to the Phase 1 ketogenic diet for dogs
What Research Says:
Both Instinctual and Ancestral diet macronutrient levels are significantly different from minimal requirements and recommended allowances outlined by the NRC
Some studies do exist supporting that the macronutrient profiles of instinctual nutrition may be more ideal for canine and feline physiologic and metabolic capacities, although some information is conflicting
Whole foods provide more health benefits than fractionated foods or single nutrients (“food synergy”)
Rendered meats have lower digestibility than raw animal products
Heat processing used to make canned foods results in decreased digestibility
High temperatures (over 392F) used in extruded foods (dry pet foods) lower nutrient content compared to lower heat (under 320F)
High moisture foods (over 73%) were shown to decrease urinary tract disease in cats
Digestibility of dry kibble was significantly less than a raw beef or cooked beef diet, which were equally digestible
Pasteurization of raw animal products in raw diets, or thorough microbiological testing, can help decrease incidence of bacteria shedding in the stool of raw fed pets