Dog Nutrition: Guide to Dog Food Nutrients

Tiffany Tupler, DVM, CBCC-KA
By Tiffany Tupler, DVM, CBCC-KA on Feb. 1, 2021

In recent years, pet parents have become more and more aware of what they are feeding their dogs. However, with all of the different dog food formulas and brands, it can be hard to figure out what really makes a dog food nutritious and balanced.

This article will explain everything you need to know about dog nutrition and provide a guide for what you need to look for in a dog food.

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What Goes Into a Nutritional, Balanced Dog Food?

A complete and balanced diet includes proteins, fats, carbohydrates, vitamins, and minerals. Water is also essential to life and is needed daily. This may seem very simple and easy with the basic ingredients broken down, but understanding how each nutrient is used in a dog’s body, understanding the processes, and knowing how much of each nutrient is needed for a healthy dog at all life stages is very complex.

In fact, this process is so complex that an entire specialty in veterinary medicine is dedicated to small animal nutrition—the American College of Veterinary Nutrition. But as a pet parent, the main things you need to know about dog food nutrition are:

Complete and Balanced Dog Food Should Follow AAFCO Guidelines

AFFCO is a private, nonprofit organization that defines the ingredients used in animal feed and pet food.

AAFCO helps ensure that animal feed and pet food products have undergone the appropriate analyses and have the necessary, required nutrients. A nutritional adequacy statement by the Association of American Feed Control Officials (AAFCO) helps pet parents identify products that meet their dog’s daily nutrient requirements.

AAFCO Label Requirements

Every pet diet and supplemental diet should include a statement from AAFCO and proper labeling to help consumers understand how much of each nutrient is needed daily and for what life stages. Keep in mind that pet food labels are different than human food product labels, which makes comparing food products difficult.

There are eight things that 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. Quality statement

  4. Guaranteed analysis. This lists the percentage of each of the nutrients in the food. It must be given in a particular order, in specified units, and as a minimum or maximum, depending on the nutrient.

  5. Ingredient statement

  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

AAFCO Nutrient Requirements

AAFCO states that are six essential nutrients that are required in order to support life and function in dogs. These are:

  1. Water

  2. Carbohydrates (including fiber)

  3. Vitamins

  4. Minerals

  5. Fat

  6. Protein

Balanced Dog Food Should Meet Your Dog’s Energy Requirements

Energy requirements for dogs can vary depending on many factors. It is important to meet your dog’s specific energy requirement to sustain their daily lifestyle. Some factors include:

  • Growth

  • Reproduction (intact vs. altered)

  • Adult age groups (young, middle, and older)

  • Activity level

  • Breed

  • Medical and behavioral conditions

A large portion of energy in the diet comes from fats and proteins, followed by carbohydrates. The energy content of a diet determines the quality of the food and how much food should be consumed on a daily basis. The diet should meet the daily energy requirements of your dog’s individual needs.

All nutrients should be balanced to ensure they are absorbed properly by the body and appropriately used for each bodily system. If the diet does not supply enough energy, your dog's gastrointestinal tract will physically be unable to consume enough of that diet and they will not be able to get their required nutrients.

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

The only way to determine if a diet has enough energy is to undergo a feeding study to ensure that the ingredients are enough to maintain a healthy daily life.

Protein in Dog Food

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

When protein is broken down, it creates amino acids that are essential nutrients for dogs. Amino acids help create energy for dogs and sustain life. There are 10 essential amino acids that 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 since dogs cannot digest plant fiber as easily as other sources. In theory, dogs can be sustained on a completely plant-based protein diet, but that diet may need various sources of protein in order to reach a daily minimum that can safely be absorbed.

For the safety of your dog, it is best to consult with a board-certified veterinary nutritionist or a primary care veterinarian who practices nutritional health if you are considering a vegetarian or vegan lifestyle for your dog. It is very important that vegetarian diets have undergone food trials and are formulated and balanced by a board-certified veterinary nutritionist.

You should also have a bi-yearly nutritional recheck to ensure that your dog is in good health. These rechecks consist of a physical examination, ideal body weight review, body condition scoring, and blood and gastrointestinal absorption testing.

What Does Crude Protein Mean?

Crude is just a word to encompass all the ways that protein is 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.

One of many methods used to determine protein quality is the Biological Value (BV). It measures the mass of nitrogen incorporated into the body divided by the mass of nitrogen from protein in the food multiplied by 100.

A value of 100% means all of the dietary protein eaten and absorbed becomes protein in the body.

Protein Quality

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

  • Protein source

  • Number of amino acids in the food

  • Availability

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

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

In many cases, to avoid this, multiple protein sources may be fed in one diet to prevent the absence of certain amino acids.

How Much Protein Does My Dog Need?

The minimum dietary protein requirement for a growing dog is 18% dry matter, or DM, and 8% DM for an adult dog. This is based on feeding a high-quality protein and again, is a minimum amount.

AAFCO recommends that the daily requirements for dog diets should contain at least 22% DM for growth and 18% DM for maintenance.

Current research states that there is no added benefit to excess protein in the diet. The maximum amount for any life stage should not exceed 30% DM.

Excess protein is otherwise excreted from the body, and in some conditions, 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 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 occurs in many locations in the body, but 90% of it is in the kidneys and liver.

Reducing total protein intake and nonessential amino acids can help minimize the workload on these organs. It is best to consult with your veterinarian or a board-certified veterinary nutritionist if you are considering a protein-specific diet due to your dog’s condition.

Can Dogs Be Allergic to Certain Proteins?

Food allergies in dogs are uncommon and are determined after ruling out environmental and seasonal allergies. About 85% of itchy dogs have an allergy to insect bites (a condition called flea allergy dermatitis, or FAD) that causes a mild to severe immune response that can mimic other conditions.

Typically, dogs that present with skin and ear issues have a higher chance of having environmental or seasonal allergies.

Common skin allergies can often be managed by therapies such as:

  • Canine-specific allergy medications

  • Monthly parasite preventatives and repellants

  • Supplements

If you are 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

Fats are lipids that are solid at room temperature and are composed mainly of triglycerides. Dietary fats are the most concentrated form of energy in pet foods (2.25 times more calories than proteins or carbohydrates).

Fat has many roles in the body, such as providing energy and helping with the absorption of fat-soluble vitamins. One of the most important roles is providing essential fatty acids (EFAs). EFAs help with inflammation at the cellular level and help dogs maintain healthy skin and coat quality. There are two important polyunsaturated fatty acids—omega-3 and omega-6 fatty acids.

Deficiencies in fatty acids can decrease wound healing and create a dull and dry hair coat, and they may increase certain dermatological conditions. High-fat diets can increase the risk of obesity and also require an increase in vitamin E supplementation since it is involved in antioxidant protection.

The requirement of fat for absorption of fat-soluble vitamins is 1% to 2% of the food.

Sources of Fat in Dog Food

There are quite a few sources of essential fatty acids that support a dog’s health.

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, eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), may or may not be essential in a dog's daily diet.

Omega-3 fatty acids may be recommended by your veterinarian to help reduce inflammation caused from conditions like arthritis, certain cancers, burns, dermatitis, inflammatory bowel disease, and kidney disease. Omega-3 is also is 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 are needed in a dog’s daily diet as they 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 with carbohydrates, then it will take amino acids 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 and health. It keeps the colon healthy along with the microbes of the gut.

The measure of fiber is reported as crude fiber (the insoluble portions). 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 (gums also improve canned food texture). Gum is a term used for a group of viscous and sticky polysaccharides found in seeds and plants.

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

Insoluble Fiber

Insoluble fiber comes from grains in a dog’s diet. It generally increases fecal bulk but does not soften feces as it cannot absorb water. It is 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.

Sources of Carbohydrates

Carbohydrates can be broken down into three groups:

  • Simple sugars

  • Oligosaccharides

  • Polysaccharides

All three play a crucial role in the daily diet of dogs.

Polysaccharides, also known as complex carbohydrates, can be further defined based on how they are digested in the body. Sugars can be found in fruits and honey. Corn, wheat, rice, barley, oats, and potatoes are all good sources of starch (a polysaccharide) for dogs.

Depending on the level of digestibility (slow, moderate, or fast), wheat bran, rice bran, apples, and guar gum are good sources of starch for dogs. For a healthy dog, there is no such thing as a bad source of carbohydrates, but you can define them based on how they are digested in your dog’s body.

The glycemic index ranks dietary carbohydrates based on how they affect the blood sugar (glucose). Carbohydrates that are lower on the index are considered for dogs that have glucose intolerance and may be used in certain medical conditions. There are a small number of clinical diseases that can be managed with these diets.

As always, these diets should only be used under the guidance of a board-certified veterinary nutritionist or your primary care veterinarian. If you are considering a nontraditional diet for your dog that is limited ingredient or without carbohydrates, it is very important that you speak with your primary care veterinarian or a board-certified veterinary nutritionist to determine what diet is best for your dog’s individual needs.

Many of these diets are used during food trials, but due to potential health risks should be used under the direct supervision of your primary care veterinarian or a board-certified veterinary nutritionist.

How Many Carbs Does My Dog Need?

There is no specific required amount of carbohydrates for dogs. AAFCO does not have a requirement for carbohydrates due to traditional preparations of commercial diets.  

Commercial dog foods contain enough carbohydrates to meet the daily amount of glucose that is needed. Glucose is needed to maintain the nervous system and keep it functioning normally.

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 due to commercial preparations. It’s important to note that a diet without any added carbohydrates 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 neurologic function.

There are five characteristics for a nutrient to be considered a vitamin:

  1. The nutrient must be an organic compound that is not a fat, carbohydrate, or protein.

  2. It is a required component of the diet.

  3. It is essential in small amounts for normal function.

  4. It causes a deficiency or decreases normal functioning when missing.

  5. It cannot be naturally synthesized (made in the body) in quantities sufficient to support normal 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 since multiple vitamins are sometimes needed to complete a reaction.

It’s very important to monitor sources of vitamins in a dog’s diet since deficiencies and excessive amounts can occur due to the inconsistencies in natural food products (liver, lungs). It may be preferred to use a vitamin and mineral supplement to ensure proper amounts.

Which Vitamins Do Dogs Need?

There are quite a few vitamins that dogs require from their food. They can be separated into two categories: fat-soluble and water-soluble.

Fat-Soluble Vitamins

Fat-soluble vitamins require bile salts and fat in order 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 deficiency and/or toxicity.

Vitamin A

Vitamin A, also known as retinol, is essential for normal vision, growth, reproduction, immune function, and healthy skin.

AAFCO recommend 5,000 IU/kg DM for dogs for all life stages.

Vitamin A deficiency can cause night blindness and skin issues. Toxicity can occur with over-supplementation and can cause bleeding and abnormal bone growth and formation.

Natural sources with the highest amounts of vitamin A include:

  • Fish oil
  • Liver
  • Egg
  • Dairy products

Vitamin A is not stable on its own, and in many cases, needs a protective coating to ensure absorption. Deficiencies can cause decreased eating or anorexia, stunted growth, dull hair coat, and weakness. Toxicities can cause stunted growth, anorexia, and bone fractures.

Vitamin D

Vitamin D, also known as cholecalciferol (D3) and ergocalciferol (D2), is essential for dogs since they are unable to produce it naturally in the body. Vitamin D helps the intestine with absorption and helps to retain calcium and phosphorus in the bone.

AAFCO recommends 500 IU/kg DM for dogs for all life stages.

Marine fish and fish oils are the richest natural sources, but they can pose a risk for overdose. Other sources include freshwater fish, eggs, beef, liver, and most dairy. The most common synthetic sources are vitamin D3 and vitamin D2 supplements.

Deficiencies can cause rickets, enlarged joints, osteoporosis, and other bone issues. Toxicities can include hypercalcemia, decreased eating or anorexia, and lameness.

Vitamin E

Vitamin E, also known as alpha-tocopherol, functions as an antioxidant in the body.

Deficiency can cause decreased eating or anorexia, skin and immune issues, and neurologic concerns in dogs. It is the least toxic fat-soluble vitamin. Toxicity is rare but can interfere with clotting times and mineralization of the bones.

AAFCO recommends 50 IU/kg DM for dogs.

Only plants synthesize vitamin E. Vegetable oils, seeds, and cereal grains have the richest sources of vitamin E for dogs.

Vitamin K

Vitamin K, also known as menadione, is involved in blood clotting and bone development.

There is no recommended allowance for vitamin K in dogs, but AAFCO recommends 1.64 mg/kg for puppies and adults.

Deficiencies of vitamin K can cause prolonged clotting times and hemorrhage. They can occur due to underlying medical conditions that impair absorption of vitamin K in the gut (such as inflammatory bowel disease). Certain forms of vitamin K can cause anemia and jaundice.

If vitamin K supplementation is recommended by your veterinarian, ask which sources would be best for your pet. Foods such as alfalfa meal, oilseed meals, liver, and fish meals are rich sources of vitamin K.

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 common.

There are nine essential water-soluble vitamins in dogs:

Thiamin (B1)

Thiamin (B1) is involved in many enzymatic reactions in the body and also helps with the nervous system.

AAFCO requires 1mg/kg DM for dogs regardless of their life stage.

Thiamin-rich sources are whole grains, yeast, and liver. Animal tissue and meat can be good sources as well.

Thiamin deficiencies are rare due to the adequate amount of thiamin that is present in commercial dog food. A deficiency can cause heart and nervous system issues such as decreased eating or anorexia, weight loss, muscle weakness, seizures, ataxia, and enlargement of the heart.

Overdoses can cause decreases in blood pressure and heart and respiratory issues.

Riboflavin (B2)

Riboflavin (B2) is involved in many systems in a dog’s body.

AAFCO requires 2.2 mg/kg DM for dogs.

Deficiencies are uncommon, but they can cause stunted growth and weight loss, as well as neurological, skin, heart, and eye issues. Overdoses are not common and have minimal side effects.

Pyridoxine (B6)

Pyridoxine (B6) is involved in amino acid metabolism along with other body systems. It also helps with the creation of neurotransmitters.

The AAFCO recommended amount is 1mg/kg.

Vitamin B6 is found in many sources of foods and in the highest amounts in meats, whole-grain products, vegetables, and nuts.

Deficiencies can cause decreased eating or anorexia, weight loss, stunted growth, anemia, convulsions, weakness, and kidney issues. Toxicities appear to be rare, but they may include signs of ataxia, signs of weakness, and falling down.

Niacin (B3)

Niacin (B3) is involved in many enzymatic and physiologic reactions in a dog’s body.

The AAFCO requirement is 11.4 mg/kg DM.

Foods rich in niacin are yeast, animal/fish by-products, cereals, legumes, and oilseeds. Niacin is added to most commercial pet foods.

Deficiencies include decreased eating or anorexia, diarrhea, dermatitis, dementia, stunted growth, soft tissue damage to the oral cavity (such as necrosis of the tongue), drooling, and in some cases, death. Toxicities are rare but can cause blood in the feces and convulsions.

Pantothenic Acid (B5)

Pantothenic acid (B5) helps with the metabolism of fat, protein, and carbohydrates, along with other body systems. It plays a crucial role in the production of energy.

AAFCO recommends 10mg/kg DM for dog s of all life stages.

It is found in all foods, but highest in meats (liver and heart), rice and wheat bran, alfalfa, peanut meal, yeast, and fish. Calcium pantothenate is the predominant form added to pet foods.

Deficiencies are very rare, but they can cause weight loss, a weakened immune system, and heart issues. No toxicity levels are noted in dogs, but it can cause gastrointestinal upset in large doses.

Cobalamin (B12)

Cobalamin (B12) is the largest and most complex of the B vitamins. It is involved in the metabolism for many systems in a dog’s body, such as folate, and is important to cell function.

The AAFCO requirement is 0.022 mg/kg for dogs.

Certain microorganisms are able to create cobalamin. Plants have very small amounts of vitamin B12. Meat and some milk products are good sources.

Deficiencies are not common, but they can cause anemia, poor growth, and neurologic issues. Long-term feeding of certain vegetable-based diets can lead to a lack of vitamin B12. Toxicities are not known in dogs but can cause abnormal reflexes and other neurologic conditions.

Folic Acid (B9)

Folic acid (B9) helps with the synthesis of DNA and purines.

AAFCO recommends 0.18mg/kg DM for dogs.

Folic acid is found in many foods (liver, egg yolks, and green vegetables), but it can be unstable or destroyed by heating, freezing, and storing in water.

Deficiencies can include decreased eating and an inability to maintain or gain weight, decreased immune function, and blood issues (anemia, clotting issues). Certain medications (sulfa drugs) can interfere with absorption. No toxicities are known in dogs.

Biotin (B7 or H)

Biotin (B7 or H) is involved in many reactions in a dog’s body that help with metabolism of fats, sugar, and amino acids.

There is currently no recommended amount for dogs.

Biotin is present in many foods, but in low quantities. Oilseeds, egg yolks, alfalfa meal, liver, and yeast have the most biotin. Many times, commercial pet foods have biotin supplemented.

Deficiencies in dogs are rare but can occur after feeding raw egg whites and certain antimicrobials. Raw egg whites can bind to biotin and make it unavailable to a dog’s body. A decrease in biotin can cause an increased production of keratin, along with dermatitis, hair loss, and a dull coat. There may be signs of stunted growth along with neurologic issues. No toxicities are known.


Choline is found in cell membranes. It decreases fat absorption in the liver, is important in clotting and inflammation, and helps with other body functions. Dogs can synthesize choline in the liver. It is not considered a vitamin but is essential and is added to many commercial diets.

AAFCO recommends 1,200 mg/kg DM for dogs.

Egg yolks, glandular meals, and fish are the richest animal sources, while cereal germs, legumes, and oilseed meals are the best plant sources.

Deficiencies include fatty livers (in young dogs), increased blood clotting times, stunted growth, kidney issues, and decreased eating or anorexia. No toxicities are known in dogs. All-natural fats contain some choline. Lecithin is an effective emulsifying agent in foods and is the form of choline ingested in most foods.

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.

Diets that have an AAFCO statement should be complete and balanced with all required vitamins. Even though confirming the percentage of vitamins in the diet is difficult, supplementation of a dog’s daily diet 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 a board-certified veterinary nutritionist to ensure that your pet is meeting his or her daily nutritional requirements.

They can also discuss supplements and confirm any questions regarding pet food labeling. Over-the-counter human and canine supplements in many states are not required to undergo food studies or bioavailability testing, meaning some products may not be readily available for dogs.

Bioavailability can only be confirmed through clinical and safety trials, which show the percentage of what is available, what the active and inactive ingredients are, and what can be absorbed.

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

Minerals are main structural components of the body’s organs and tissues, body fluids and electrolytes, and muscle contractions. They are involved in enzyme and hormone systems.

There are two kinds of minerals: macro-minerals and trace minerals. Both have daily requirements for dogs, but in different amounts.

Minerals help with many functions of a dog’s body and support structures. Without a completely balanced mineral profile, many biological systems will stop functioning, which can lead to serious medical conditions and even death.

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.


Macro-minerals are required at greater than 100mg/Mcal. Below are the required macro-minerals.

Calcium (Ca)

Calcium (Ca) makes it possible for teeth and bones to maintain their shape and is actively involved in balancing calcium in a dog’s bone. It is also very important in cell communication and is involved in blood clotting, muscle function, and nerve transmission.

About 99% of all calcium is stored in the teeth and bones.

Too little or too much calcium can create an imbalance in phosphorus-calcium levels. Deficiencies in calcium can cause bone reabsorption, decreased growth, decreased eating or anorexia, limping, lameness, fracturing of the bone, loose teeth, and convulsions. Low calcium can occur in kidney failure, pancreatitis, and eclampsia.

Supplementation may be required but should be done under the strict supervision of a veterinarian due to the risks of mineral imbalance. Excess amounts of calcium can cause limb lameness and joint swelling. It can also cause certain conditions such as secondary hyperparathyroidism.

Phosphorus (P)

Phosphorus (P) is vital in many tissues and functions in a dog’s body. It is the second structural component of bone, teeth, RNA, and DNA. It is important for cell growth, cell energy use, and amino acid and protein formation.

AAFCO recommendations are 0.8% for growth and 0.5% for maintenance (adults).

Most of the phosphorus comes from a dog’s diet and is available more readily in animal-based ingredients than plant-based ingredients (phytic acid). Meat tissue (poultry, lamb, fish, beef) is high in phosphorus, followed by eggs, milk products, oilseeds, protein supplements, and grains.

Deficiencies can cause pica, decreased growth, poor hair coat, and bone fractures. Excessive amounts can cause loss of bone mass, urinary stones, the inability to gain weight, and calcification of tissues and organs.

Magnesium (Mg)

Magnesium (Mg) is involved with the structural composition of bones, plays a role in the metabolism of carbohydrates and fats, and is a part of neuromuscular activity.

AAFCO recommends 0.04% DM for growth and 0.08% DM for maintenance (adult dogs).

Bone products (such as bone meal or lamb meal), oilseed, flaxseed, soybean meal, unrefined grains, and fibers are good sources of magnesium.

Deficiencies can cause stunted growth, muscle contraction and mobility issues, and decreased eating or anorexia. High levels can cause stone formation and paralysis. Kidneys are very important in the regulation of magnesium. The use of certain drugs (cyclosporin, diuretics, etc.) and certain medical conditions can cause an imbalance.  

Potassium (K)

Potassium (K) is the most abundant inside the cells of a dog’s body. It helps in many functions of the body, such as maintaining acid-base balance and osmotic balance, transmitting nerve impulses, and muscle contractility. It is not stored in the body and needs to be supplemented in the diet.

AAFCO recommends 0.6% DM for dogs in all life stages.

Soybean meal, unrefined grains, fiber sources, and yeast are excellent sources of potassium.

Deficiencies can cause decreased eating or anorexia, lethargy, and trouble walking. Over-supplementation is rare but can cause heart and muscle issues.

Sodium (Na) and Chloride (Cl)

Sodium (Na) and chloride (Cl) are important in maintaining osmotic pressure, acid-base balance, and what enters and leaves the body’s cells. Sodium is also important in calcium absorption and the absorption of several water-soluble vitamins.

Deficiencies can cause decreased eating or anorexia, weakness, fatigue, and hair loss. Over-supplementation does not typically occur unless good, quality water is not readily available, but it can cause constipation, seizures, and in some cases, death.

Trace Minerals

Trace minerals, also known as microminerals, are required at less than 100mg/Mcal. Below are the required trace minerals.

Iron (Fe)

Iron (Fe) Iron is very important for oxygen transport throughout a dog’s body. Deficiencies can cause anemia, a rough coat, lethargy, and stunted growth.

AFFCO recommends 80mg/kg for dogs in all life stages. Foods rich in iron are most meat ingredients (organ meats—liver, spleen, and lungs) and some fiber sources.

Excessive amounts in the diet can lead to decreased eating or anorexia, weight loss, and liver issues.

Copper (Cu)

Copper is important in the formation and actions of different enzymes in a dog’s body, hemoglobin formation (oxygen movement), cardiac function, bone and myelin formation, connective tissue development, and immune function. The liver is the main location of copper metabolism.

AAFCO recommends a minimum of 7.3mg/kg DM for dogs.

Most meats (organ meats from cattle in particular) are rich in copper. The availability of copper in food can vary, making it hard to supplement.

Deficiencies can cause abnormal growth, changes in hair color, bone issues, and neurological conditions. Certain breeds of dogs are susceptible to liver toxicity from too much copper (Bedlington, West Highland White, and Skye Terriers). Excessive amounts can cause hepatitis and increases in liver enzymes.

Zinc (Zn)

Zinc is involved with over 100 enzyme functions, protein synthesis, carbohydrate metabolism, skin and wound healing, and the immune system. Zinc is not a toxic substance, but over-supplementation is not recommended since it can interact with other minerals and decrease absorption.

AAFCO recommends 120mg/kg DM for dogs. Foods high in zinc are most meats and fiber sources.

Deficiencies include decreased eating, stunted growth, hair loss, a weakened immune system, and growth disorders. Certain arctic breeds can have deficiencies (Alaskan Malamutes and Siberian Huskies) that may require supplementation even with adequate dietary food levels.

Manganese (Mn)

Manganese is involved in many systems, such as fat and carbohydrate metabolism and bone and cartilage development.

AAFCO recommends 5 mg/kg DM for dogs.

Foods rich in manganese are fiber sources and fish meals.

Deficiencies can cause deformities of the bone and poor growth.

Selenium (Se)

Selenium is involved with the immune system, protects cells from oxidative damage, and is involved in normal thyroid function.

AAFCO requirements are 0.11mg/kg DM for dogs.

Fish, eggs, and liver are food products that are high in selenium.

Deficiencies are rare since vitamin E can act as a replacement for selenium in some functions. Prolonged deficiencies can cause a decrease in eating and edema of the body. Excessive amounts can cause vomiting, muscle spasms, falling and weakness, excessive drooling, decreased eating or anorexia, trouble breathing, foul-smelling breath and odor from the mouth, and nail issues.

Iodine (I)

Iodine is involved with proper function of a dog’s thyroid. The thyroid helps regulate body temperature and is involved in growth and development, skin and hair repair and care, and neuromuscular function.

AAFCO recommends 1.5mg/kg DM for dogs.

Fish, eggs, and iodized salts are food products that are high in iodine. Iodine supplements typically found in commercial foods include calcium iodate, potassium iodide, and cuprous iodide.

Deficiencies and excessive amounts cause the same medical issues such as a goiter, including enlarged thyroid glands, hair loss, lethargy, weakness, decreased eating or anorexia, and fever.

Water Requirements for Dogs

Water is considered the most important nutrient since it performs 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.

In general, the average daily water requirement for a healthy, altered dog is 2.5 times the amount of dry matter they eat.

Another way to think of the amount of water a dog should consume daily is that it is equal to the amount of energy (food content) that is taken in. This depends on many factors that affect the body (age, gender, size, stress, etc.) and the volume of dry matter that is consumed through the diet.

On average, a dog being fed a moist diet will drink less water throughout the day due to higher moisture content (about >75% less).

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 completely possible, and with some medical conditions, may be needed. Keep in mind that not all foods that benefit people can be absorbed, tolerated, or are even safe for your dog.

As a pet owner, you should consult with an expert in the field to ensure that your pet’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.

In the meantime, BalanceIt is a website created by board-certified veterinary nutritionists to help with the creation of homemade pet food diets. This website should be used in conjunction with a nutritional consultation and with the help of your veterinarian to ensure the correct amounts of ingredients are added for your pet’s individual needs.

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Tiffany Tupler, DVM, CBCC-KA


Tiffany Tupler, DVM, CBCC-KA


Dr. Tiffany Tupler is a graduate from the University of Florida College of Veterinary Medicine with a certificate in shelter medicine and...

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