Dog Nutrition: A Guide to Dog Nutrients

With so many dog food formulas and brands available, it can be hard to figure out what really makes a dog food nutritious and balanced. 

Ahead, learn everything you need to know about dog nutrition, including what to look for in a dog food. 

What Goes Into a Balanced Dog Food?

According to the Association of American Feed Control Officials (AAFCO), six essential nutrients are required to support life and function in dogs: 

1. Water

2. Carbohydrates (including fiber)

3. Vitamins

4. Minerals

5. Fat

6. Protein

This may seem like a simple list, but understanding how each nutrient is used in a dog’s body and knowing how much of each nutrient is needed for a healthy dog at all life stages is very complex. 

Complete and Balanced Dog Foods Should Follow AAFCO Guidelines 

What Is the AAFCO? 

The AAFCO is an independent, nonprofit organization that helps ensure that animal feed and pet food products have undergone the appropriate analyses and have the necessary required nutrients.  

AAFCO Label Requirements 

Pet food labels differ from human food product labels, which makes comparing food products difficult. 

The following eight elements should be included on the bag or can: 

1. Brand and product name 

2. Name of species for which the pet food is intended 

3. Quantity statement (net weight or volume) 

4. Guaranteed analysis (the percentage of important nutrients in the food) 

5. Ingredient statement (list) in order, from most to least predominant by weight  

6. Nutritional adequacy statement that “indicates that the food is complete and balanced for a particular life stage, such as growth, reproduction, adult maintenance or a combination of these, or intended for intermittent or supplemental feeding only” 

7. Feeding directions 

8. Name and address of manufacture or distributor 

Food manufacturers' diets that meet AAFCO standards for complete and balanced nutrition include brands like Hill’s, Purina, and Iams. 

Balanced Dog Food Should Meet Your Dog's Energy Requirements 

Energy requirements for dogs can vary depending on many factors. It’s important to meet your dog’s specific energy requirement to prevent unwanted weight gain or loss. 

A large portion of energy in the diet comes from fats, followed by proteins and carbohydrates. The energy content of a diet determines how much food should be consumed daily, and the concentration of other nutrients needs to be based on that. 

For example, dogs eating a diet that is high in energy will eat a smaller amount. It’s important in this case to ensure that the percentage of other essential nutrients is high enough to meet the smaller volume consumed. 

Protein in Dog Food

Proteins are important in the formation and maintenance of muscle, skin, hair, nail, cartilage, tendons, and ligaments. Protein in dog food also assists with hormone, antibody, and blood formation. 

When protein is broken down, it creates amino acids that can be reassembled into the proteins a dog needs. Proteins can also be a source of energy for dogs.  

Ten essential amino acids are needed for dogs to maintain a healthy life. These nutrients cannot be created in the body and must be supplied in the diet. 

Sources of Protein in Dog Food 

Animal protein sources have the highest amounts of essential amino acids. Proteins from plants tend to have a lower digestibility, but dogs can be sustained on a completely plant-based protein diet. 

For the safety of your dog, it’s best to consult with a board-certified veterinary nutritionist or a primary care veterinarian who practices nutritional health if you’re considering a vegetarian or vegan lifestyle for your dog.

It’s very important that vegetarian diets have undergone food trials and are formulated and balanced by a board-certified veterinary nutritionist. 

What Does Crude Protein Mean? 

Crude is just a word that encompasses the ways that protein levels are calculated and determined in the diet. It does not provide information about the protein quality or the nutritional value of the protein source in your dog’s diet. 

Protein Quality 

Protein quality is how much of the protein source is converted into amino acids that can be used by the body. It’s dependent on the: 

• Protein source 

• Number and types of amino acids in the food 

• Digestibility and availability 

Proteins that provide large portions of all essential amino acids are considered high-quality proteins. 

If that protein source lacks essential amino acids or they cannot be absorbed by the body, then it is considered a low-quality protein. 

In many cases, multiple protein sources are fed in one diet to ensure that all essential amino acids are present. 

How Much Protein Does My Dog Need? 

The AAFCO minimum dietary protein requirement for a growing dog is 22.5% dry matter (DM) and 18% DM for an adult dog. This is based on feeding a high-quality protein, and remember, this is only the minimum amount. 

The maximum amount for any life stage should not exceed about 30% DM. There is no added benefit to excess protein in the diet. 

Extra protein is broken down and used for energy, and in some conditions, it can be harmful. 

Low-Protein Diets 

Feeding a high-protein or low-protein diet for prevention and management of certain diseases is a debated topic in veterinary nutrition. 

Low-protein diets may be recommended for certain conditions (chronic kidney disease or hepatic encephalitis, for example) to decrease the amount of ammonia that is present in the body. Ammonia is toxic to tissue and cells and is created as a byproduct of protein breakdown.  

Ammonia is eliminated from the body by the kidneys and liver. Reducing total protein intake and nonessential amino acids can help minimize the workload on these organs.  

It’s best to consult with your veterinarian or a board-certified veterinary nutritionist if you’re considering a protein-specific diet due to your dog’s condition. 

Can Dogs Be Allergic to Certain Proteins? 

Proteins are the usual trigger for food allergies. However, food allergies in dogs are uncommon and are diagnosed after ruling out much more prevalent environmental and seasonal allergies. 

If you’re concerned about your dog having a potential food allergy or food aversion, speak with your primary care veterinarian or a board-certified veterinary nutritionist about a clinical food trial. 

Fat in Dog Food

The AAFCO minimum levels for fat in dog foods are 8.5% DM for growth and reproduction and 5.5% for adult maintenance. Dietary fat has many roles in the body, such as:  

• Providing energy: Fat is the most concentrated form of energy in pet foods (2.25 times more calories than proteins or carbohydrates). 

• Helping with the absorption of fat-soluble vitamins 

• Providing essential fatty acids (EFAs) that help with inflammation at the cellular level and help dogs maintain healthy skin and coat quality 

Deficiencies in fats (particularly omega-3 and omega-6 fatty acids) can decrease wound healing, create a dull and dry hair coat, and increase certain dermatological conditions. High-fat diets can increase the risk of obesity. 

Sources of Fat in Dog Food 

Both plant- and animal-based ingredients can be important sources of fats and essential fatty acids in a dog's diet. 

For example, linoleic acid (LA) is the precursor of arachidonic acid, (AA) which is an essential omega-6 fatty acid. Good sources of linoleic acid are vegetable oils, chicken, and pork fat. 

Omega-3 fatty acids can help reduce inflammation caused from conditions like arthritis, certain cancers, burns, dermatitis, inflammatory bowel disease, and kidney disease.

Omega-3 is also a major player in keeping cartilage healthy and functional.

Flaxseed, canola, and marine fish oils are good sources of omega-3 fatty acids. 

Carbohydrates in Dog Food

One of the most important reasons for carbohydrates in a dog’s diet is to supply energy. 

Carbohydrates in a dog’s daily diet provide energy in the form of glucose and are a main source of dietary fiber. The body craves glucose, and if it is not available from carbohydrates, then it must use protein, taking it away from other processes in the body. 

Carbohydrates also: 

• Generate heat in the body 

• Form the base for other nutrients 

• Can be converted into fat (some carbohydrates) 

Growing animals and dogs that have high-energy needs should be fed a diet with at least 20% carbohydrates. 

Fiber From Carbohydrates 

Fiber, a form of carbohydrate, is very important for a dog’s normal gastrointestinal function. It keeps the colon healthy along with the microbes of the gut. 

The measure of fiber is reported as crude fiber (the insoluble portions) on dog food labels. Total dietary fiber is composed of both soluble and insoluble fibers. 

Soluble Fiber 

Soluble fiber retains water and generally makes a dog’s feces softer.  

Common sources of soluble fiber are fruits and gums (a term used for a group of viscous and sticky polysaccharides found in seeds and plants). 

Many soluble fibers are also fermentable. Fermentable fibers (also called prebiotics) can be used by a dog’s normal gut bacteria as an energy source. They also produce short-chain fatty acids that can be used by cells in the intestines as an energy source. 

Insoluble Fiber 

Insoluble fiber comes from grains in a dog’s diet. It generally increases fecal bulk, but because it cannot absorb water, it does not soften feces. It may be added in the form of cellulose. 

Many fiber types used for supplementation are mixed fibers with mostly soluble fiber characteristics. High-fiber diets are sometimes used to manage medical diseases such as diabetes mellitus, as well as certain gastrointestinal conditions and weight management regimens. 

Sources of Carbohydrates 

Carbohydrates can be broken down into multiple groups, all of which play a crucial role in the daily diet of dogs: 

For a healthy dog there is no such thing as a bad carbohydrate, but dog foods that are given to help manage certain health conditions may rely on one source more than another. For example, diets for dogs with diabetes are often low in simple sugars, but they contain polysaccharides and fiber to prevent spikes in glucose levels after eating.   

As always, these diets should only be used under the guidance of a board-certified veterinary nutritionist or your primary care veterinarian.  

How Many Carbs Does My Dog Need? 

There is no specific required amount of carbohydrates for dogs.  

Dry dog foods typically contain 30–60% carbohydrates, with the majority being starch. Grains such as corn, rice, wheat, barley, and oats provide the bulk of starch and are well tolerated and absorbed in dogs.

It’s important to note that a diet with lower levels of carbohydrates (some wet foods, for example) will be higher in proteins and fats. 

Vitamins in Dog Food

Vitamins are very diverse and perform many different functions in a dog’s body, such as the creation of DNA, bone development, blood clotting, normal eye function, and neurological function. 

Consuming too many vitamins over the recommended dose can lead to toxicity and other complications. Deficiencies in one vitamin can also cause a cascade of issues, because multiple vitamins are sometimes needed to complete a reaction. 

Which Vitamins Do Dogs Need? 

Dogs need quite a few vitamins in their food. These can be separated into two categories: fat-soluble and water-soluble. 

Fat-Soluble Vitamins 

Fat-soluble vitamins require bile salts and fat to be absorbed in a dog’s gut. There are four fat-soluble vitamins: A, D, E, and K. Due to the way fat-soluble vitamins are stored and used by the body, they are at the highest risk for toxicity. 

Water-Soluble Vitamins 

Water-soluble vitamins are readily absorbed and used in a dog’s body. Because of their rapid use and no available storage in the body, deficiencies are a bigger worry than toxicities. 

There are nine essential water-soluble vitamins in dogs: 

Do Dogs Need Vitamin Supplements? 

A completely balanced and formulated diet has all the daily vitamins that your dog would need. Many commercial pet food diets are fortified to meet your dog’s vitamin requirements. Supplementation is often not needed, and in many cases, can pose a risk of toxicity. 

It is very important when choosing a diet for your dog that the AAFCO statement is included.

If you are feeding a nontraditional diet that does not have an AAFCO statement, consult with a primary care veterinarian who practices advanced nutritional health or with a board-certified veterinary nutritionist to ensure that your pet is meeting their daily nutritional requirements. They can also discuss any supplements that might be needed. 

If you are considering a supplement, look for products that have a quality seal from the National Animal Supplement Council (NASC) to ensure adequate bio-availability and safety. Some medical conditions may require vitamin supplementation. This should only be done under the direct supervision of your primary care veterinarian. 

Minerals in Dog Food

There are two kinds of minerals: macro-minerals and trace minerals (also called micro-minerals).  

• Macro-minerals are needed in large amounts because they are the main structural components or are vital parts of body fluids.  

• Trace minerals are present in smaller amounts but are important parts of metabolic processes. 

Which Minerals Do Dogs Need? 

There are different types of macro-minerals and trace minerals that are needed to create a complete and balanced dog food. 

Water Requirements for Dogs

Water is considered the most important nutrient, performing many important functions such as: 

• Regulating body temperature 

• Breaking down carbohydrates, proteins, and fats 

• Providing shape and structure to the body 

• Keeping the shape of the eye 

• Lubricating joints 

• Protecting the nervous system 

Dogs get water through their diet and by simply drinking water. A dog being fed a moist diet will usually drink less water throughout the day due to the higher moisture content of the food. 

Dogs should have continuous access to clean and fresh water. It is also important to monitor their daily intake and notify your veterinarian of any increases or decreases. 

Can I Make My Own Balanced Dog Food?

Nontraditional diets, including home-prepared meals for dogs, are possible, and with some medical conditions, may be beneficial. However, most recipes you find online and in books do not provide complete and balanced nutrition for dogs. 

As a pet parent, you are responsible for ensuring that your dog's individual daily requirements are met.

Consider a consultation with a board-certified veterinary nutritionist or a primary care veterinarian who practices advanced nutritional health to ensure that all meals are balanced and formulated for your dog’s lifestyle and needs.