Hello, Wizard-in-Training!

So, you wish to learn more about pet nutrition?

Shazaam! For lack of a better phrase, you really ARE in the right place! This is the place where you can learn, ask questions, receive mentorship, and overall just have support, from a specialist who has dedicated their time and energies to the study, research, and dissemination of nutritional science of companion animals.

The guides I will provide will walk you through the very basics, to get you started on what you need to know in order to start choosing food, treats, and supplements for your dog, cat, or small pet (separate guides will be provided for the little pets!) in a manner that will optimize their health inside and out!

For support and consultations on your pet's nutrition from the wizard herself, visit facebook.com/groups/askthewizard. You can also listen to the pet nutrition podcast at anchor.fm/anw (which can also be found on iTunes, Spotify, and other podcast apps).


In this Guide, you will learn the basic physiology of your pet's Digestive System, from end to end, and how it pertains to your pet's dietary needs. This is a vital beginning step to understanding the nutritional needs of your dog or cat, equipping you to meet those needs, and creating a foundation of knowledge to build upon.

If you find, while going through these guides, that you desire more in-depth information, and you crave complex nutrition guides that include the explanations of complicated processes in your pets body, and more, that will truly make you a Wizard in Pet Nutrition, then please go visit my Patreon page, patreon.com/askthewizard.

Wizard's Note: The more advanced Patron Guides will be available shortly after these Beginner Guides, as they take longer to create. So keep your eyes peeled for announcements of new Guides both on my Patron page and here.
As supporters of the time and effort I put into my studies and research, Patrons will be getting in-depth Guides and videos to learn from. I will go over the ins and outs of…

  • Food processing
  • Synthetic vitamins versus whole food complexes
  • Macronutrients and micronutrients
  • Minerals versus trace minerals
  • Vitamin premixes and why you should avoid them
  • The concerns with Carbohydrates
  • Calculating your own pet's energy requirements
  • How to read and calculate the guaranteed analysis to determine the amount of calories coming from specific macronutrients
  • Demystify labels and their meanings
  • AAFCO definitions, guidelines, and protocols
    And much, much more..

At the end of my Patron Guides my Wizardship Graduates will receive a small token of appreciation for the dedication to learning, and for supporting the creation of my educational organization.

In the meantime - If you are ready to get started, let's go ahead and begin our Apprenticeship with the first lesson!

Okay, you wonderfully curious, magical human being - let's learn about the real magic…of nutrition!

Herbivore vs. Carnivore

You've probably heard of "species appropriate diets" many times. But what does it mean, exactly? Both carnivores and herbivores have the same nutritional needs, essentially. In fact, whenever a carnivore eats an herbivore, it's getting nutrition from what the herbivore ate. In this way, carnivores make herbivores do all the work of eating the fiber, while the carnivores spend most of their time hunting.

That's the biggest difference between carnivores and herbivores - one spends most of their time eating (as one must do when eating low-energy, high fiber foods like plants), and the other spends most of their time hunting (which one would have to, when their meals consist of high-energy proteins and fats but food is much more work, and sometimes hard to come by).

An Herbivore is an animal that obtains its nutrients from plant sources. Herbivores will spend up to 20 hours a day eating, and Carnivores instead usually have several small meals throughout the day, or one large meal. The Herbivore's food is very high in fiber, whereas a Carnivore's diet is very low in fiber. The Herbivore has a large belly, with what is essentially an internal fermentation factory. Ruminants, such as cows, for example, have a series of complex stomachs - simply for eating grass and hay!

This is a diet that is extremely low energy, low nutrition, and high fiber - so their bodies have gone to great lengths to develop complicated systems to obtain nutrients from it. Their stomachs are very low acid, especially in comparison to Carnivores, as their diets don't include the kind of pathogens you find in meat. And some Herbivores, such as rabbits and chinchillas, even have developed a system where they must re-ingest their own fecal matter (known as Caecotrophs [See-Kuh-Troughs]) in order to obtain the nutrients they missed out on during the first pass through their digestive tract.

All in all, plants are very hard to digest! Even in the case of true Omnivores, you may look at them as Carnivores that have the ability to digest some plant matter, rather than as Herbivores that have the ability to digest some meat. Simply because of the incredible lengths the body must go to in order to obtain nutrients from a plant-based diet.

Now, there are basically four steps in the digestion process for your pet, and that is the mechanical, then chemical breakdown of food, the absorption of nutrients, and then the elimination of waste and indigestible bits. The digestive tract of an animal will help dictate what kind of food should be in their diet; plants, or meat.

Firstly, 'Digestion' is the process of turning raw ingredients (the food eaten) into metabolizable and absorbable nutrients. For example, when you eat a burger, or a salad, your body goes to work breaking down all the components of that burger or salad into smaller and smaller units, obtaining the nutrients from within, and disposing of the bits it couldn't (or shouldn't) digest or absorb.

When you eat food that your body is ready and capable of breaking down, you can obtain more nutrients from the food, and avoid symptoms of indigestible food affecting your health - such as gas, bad breath, dry skin, brittle hair, inflamed bowels, and much more.

What about your pets?

Well, both dogs and cats are classified as Carnivores.

Yes, you may have heard that your dog is an Omnivore, and much of the time you will want to consider the source. If you perform an internet search to ask if your dog is an Omnivore, the largest players in the pet industry, including Purina, Hill's Science Diet, and Royal Canin, will tell you that your dog is an Omnivore, and can digest starches just fine! So why not buy their starchy kibble?

Wizard's Note: Starch is a Polysaccharide: A Carbohydrate whose molecules consist of a number of sugar molecules together. This is also known as a Complex Carbohydrate, which takes longer than Simple Carbohydrates, such as table sugar and syrup, to break down, because it has so many molecules of sugar bonded together. Throughout this guide, I may use the terms Starch and Carbohydrate intermittently. Examples of Starches/Complex Carbohydrates include: Peas, Beans, Oatmeal, Quinoa, Barley, Potatoes, Sweet Potatoes, Whole Grains, and Vegetables.

Dogs are of the Order Carnivora, and they have the second shortest digestive tract of all mammals, the first shortest belongs to the cat. And short digestive tracts, you will learn through this guide, are not ideal for breaking down tough, fibrous plant matter (such as starches).

The best way to describe your dog and your cat, in terms of their dietary designations, is that your dog is a Scavenger or Facultative Carnivore, and your cat, the truest of carnivores, is an Obligate Carnivore.

A Facultative Carnivore, or Scavenger, is primarily a meat eater, best equipped for a diet high in protein and fat, but which can survive on plant matter if absolutely necessary. Dogs do not thrive on a high-starch diet, but they can certainly survive on one.

An Obligate Carnivore, like your cat, is an animal that must eat meat to survive, and will thrive only on a diet high in animal protein, moderate in fat, and very low in carbohydrate.

So, when you hear about "species appropriate diets", that's what it means. It is in reference to the Order designation of your pet, and what they are built to eat and thrive on - or their "Physiological Food".

For both dogs and cats, that is meat.

Now let's talk about how they go about digesting that meat!

Mouth and Teeth

The function of your pet's teeth is primarily for tearing and gripping food. Adult dogs have 42 teeth, 10 of which are molars with the same function as human molars - which is to help grind foods. Adult cats have 30 teeth, none of which, including their molars, have what are called grinding surfaces (the surfaces needed to properly grind plant matter).

Both dogs and cats lack the ability to move the jaw horizontally which allows for grinding/chewing (like Herbivores ). Omnivores and Herbivores also have large, flat molars that allow them to grind plant matter. If you were to look at pictures of many Herbivores mouths, you would likely see their teeth are generally very flat and wide, and that their jaws move side to side whilst chewing. This allows for the mechanical first step of breaking down fibrous plant matter.

In a Carnivores mouth, the mechanical first step is to rip and shred meat from bone, and this is why their teeth are all sharp and/or long, and curved. One concern many cat owners have are their cats not chewing their food. This is because cats don't really "chew", they aren't built for it. Their teeth are not meant to chew, and their jaws are physically unable to make the correct "chewing" motion. Many cats will break up kibble in their mouths, however, and this is interpreted as normal chewing behavior. But for the majority of cats, chewing is a somewhat unnatural, and difficult part of eating.

The cat's mouth is more adapted to a prey diet than most other carnivores. They also have a rough tongue that helps them remove flesh from the animals they eat.

Also in the mouth, of course, is saliva, which is 98% water, but also includes a mixture of sodium, and other minerals and phosphates as well as immunoglobulins, proteins, enzymes, and nitrogenous products, such as ammonia.

Here is an interesting difference between humans and our dogs and cats; In humans, our saliva contains an enzyme that breaks down Carbohydrates into simple sugars. For us, chemical digestion actually begins in the mouth - before food even reaches our stomach!

Most mammals, in fact, have this enzyme in their mouths - but dogs and cats do not. And this reflects their expected diet, consisting primarily of meat, organs, and bones from prey. As carnivores, they are less well adapted, from tooth to tail, for eating grains and vegetation.

In fact, any starch they eat gets stuck in their teeth because of this lack of enzyme to help break it down, which also means Carbohydrates in the diet help lead to plaque, tartar, and tooth decay. As I have discussed in one of my live Q&A Sessions, kibble does not clean teeth. This is part of the reason why kibble, which is anywhere from 30% - 70% Carbohydrate, is not a method of keeping your pet's teeth clean and healthy.

The Digestive Tract

The stomach wall is folded and muscular, which increases the surface areas, and mixes and blends the food. The stomach also houses several glands which produce "digestive juices", mainly to break down protein, bone, and destroy bacteria that are sensitive to strong acids (which is why your dog and cat are so well adapted for eating raw meat). The stomach will store food and liquid, mixing and digesting them in these juices, and slowly empty, eventually, into the small intestine. There is quite a bit more that goes on here, but these are just the basics.

Now, the entire Gastrointestinal Tract, or GI Tract, is lined with a mucus membrane that protects it. Both from sharp edges such as from bone or claws in their food, and from the powerful enzymes, built to break down tissue, coming from the upper gut. As these enzymes are designed for breaking down tissue, it's very important to keep that mucus membrane healthy - for it prevents the GI Tract from digesting itself!

In the small intestines more specialized enzymes break the foods down further. Fat, Carbohydrates, and Proteins are broken up into usable units at different stages.

Situated away from the central point of the stomach (or distal) is the Pancreas, which is both an organ and an endocrine gland, whose main job is to produce hormones and pancreatic juice - a digestive enzyme blend to help digest and absorb nutrients in the small intestine.

The pH of the stomach largely dictates the actions the pancreas takes in digestion, and a compound called Trypsin Inhibitor keeps the enzymes within the pancreas inactive until they reach the intestines. These Inhibitors are crucial - to protect the pancreas from being destroyed by its own enzymes - which is essentially what acute pancreatitis is, and why it's potentially fatal.

Many more enzymes are found in the lining of the wall of the small intestines, that perform a variety of functions, continuing the process of the food breakdown.

The food then passes through its last stop, the large intestine (or the colon). It's main role is really water regulation; it absorbs liquid and sodium before the food is passed out of the body as feces.

In cases of bacterial infection or food poisoning it can also do the opposite and add water into the feces in order to help flush the irritants out of the body. The results of which are uncomfortable, as anyone who's experienced food poisoning would know, but they do serve an important purpose.

The beneficial bacteria within the large intestine also play a huge role here - in digesting food and keeping out bad bacteria. They also produce valuable micronutrients as a by-product of eating some of the food passing through. This is one of the many Microbiomes I will discuss throughout these guides, and it is pivotal to your pet's health. Protecting your pet's Microbiome is the best, and really only way, to have a healthy, thriving animal.

Again, the dog and cat have the shortest digestive systems of any mammals. A short digestive tract is typical of carnivores. It can take 8-9 hours for food to pass through the entire digestive system. This process is slower in puppies and kittens, because their system isn't mature yet. It takes time for the gut and microbiome to become fully functional.

For comparison, the ratio of body length to intestinal tract in an Herbivore like a Horse is 1:12, whereas for your Obligate Carnivore, the cat, it's 1:4! For dogs, it's 1:6.

Wizard's Note: Just as a fun aside, for humans, the ratio is 1:15.

The large intestines of both dogs and cats are far smaller than that of Herbivores or Omnivores like horses and pigs which allows food to pass through much quicker. The large Intestines and hind guts of Herbivores are largely for fermenting fiber so they must be much longer.

But remember, Omnivores, like pigs and humans, still have an easier time digesting meat than plants, as we are not Herbivores, and therefore don't have the complex systems in place that rodents and ruminants have to really obtain the most nutrients from plants. As omnivorous primates, humans can thrive on a variety of foods; meats, organs, fish, eggs, fruits, and vegetables. And, while our systems are much longer than our pets, even we don't thrive on a diet that is heavy on starches and sugars.

Wrapping Up...

And that is the basics of your pet's Digestive System. You are now able to easily tell the difference between an Herbivore and a Carnivore, have a basic understanding as to why a short, acidic digestive tract is not designed for plant matter but for meat and bone, and you can now see that our dogs and cats are Carnivores, and that their physiologically appropriate diet is one that consists of meat.

Stay tuned for the next Guide!