Everything You Need To Know About Dog Nutrition

Published: 20 Apr 2024
Ashley Marlton
Ashley Marlton
Dr. Marlton spent her first two years in practice working as a veterinary assistant at a 24-hour emergency care animal hospital in Michigan prior to moving to Miami. Following graduation, Dr. Marlton attended Colorado State University College of Veterinary Medicine & Biochemical Sciences in Fort Collins while participating in volunteer spay neuter trips.
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Today’s pet owners possess increased awareness regarding the nutrition they present to their pets. However, despite their intention to procure only the finest for their dogs, choosing the appropriate dietary choices among the vast options available in the market, or pinpointing particular ingredients that might trigger food sensitivities, continues to be a daunting task. Moreover, it is not easy to determine which dog food brand is superior to another.

This article will help you answer these concerns and guide you with all the things that you need to know about your dog’s nutrition including points to look out for when buying your dog’s food.

Nutrient Requirements For Dogs

Nutrients for your dogs are obtained from the dog foods that you give them. They use it as a source of energy to sustain metabolic processes for maintenance and growth. As responsible dog parents, you should be well aware of the six essential classes of nutrients needed for your dog to live a healthy life.


Water plays a huge role in your pet’s health. In fact, your dog’s body accounts for approximately 60 to 70 percent of every adult dogs’ body weight. Some vital functions of water include mobility of nutrients to cells and body tissues, body temperature regulation, and flushing waste out of the body.

Having said that, as a responsible pet owner, you should provide clean and fresh water accessible for your pet at all times since the moisture content in pet foods(e.g. wet foods have 10% moisture & canned pet foods have 78%) you give your dog would not suffice.

Most importantly, the lack of sufficient water means nutritional requirements are not met. If this happens, this may lead to serious consequences to your pet as a decrease in water in the body by 10 percent may entail serious illnesses while having 15% and above water level would result in fatality.


Proteins are the basic building blocks of cells, tissues, internal organs, enzymes, antibodies, and hormones. It is also equally important for the formation and maintenance of ligaments, tendons, and cartilage. In this respect, protein in dog food helps with your dog’s individual muscle development, skin, coat, nail, and blood formation.

Protein is a much larger nutrient compound that when broken down, produces amino acids that are one of the essential nutrients for most dogs. These essential amino acids are needed for your healthy dog to maintain bodily functions. To emphasize, these essential nutrients are not naturally occurring in pups, so they should be purposely given through the dog foods you give to your dog’s daily diet.

Animal protein sources relatively have the highest concentrations of amino acids. Plant-based proteins, on the other hand, can be poorly digested because dogs can’t totally digest plant fiber compared to other protein sources[1].

If you wish to transition your pet’s diet to a completely vegetarian lifestyle and for your dog’s safety, you may want to consider talking to a veterinary nutritionist or veterinarian who practices nutritional health in order for your dog to stay healthy despite going vegan. While theories suggest that a dog can be sustained on a plant-based protein diet, it is still best to consult a professional that is knowledgeable regarding this topic to ensure the optimum health of your dog instead of deciding on your own.

Protein quality is a good indicator of how much of the protein source is processed into essential amino acids, which are absorbed by your dog’s body tissues. This quality is highly dependent on the number of amino acids present in the food, the availability, and the protein source of the dog food.

A Dog Food Formula For Your Dog's Weight Maintenance

Moreover, high-quality proteins in pet foods are labeled that way because of their capability of providing large portions of essential amino acids. Low-quality proteins, on the contrary, are sources that lack essential amino acids or can’t be absorbed by your dog. Because of this, multiple protein sources are added to some dog diets to prevent the absence of specific amino acids.

To ensure the protein quality of your dog’s food, you can use Biological Value (BV) or choose from many other methods to determine the protein quality. BV, for example, measures the mass of nitrogen incorporated into the body. To use this, you need to divide the mass of nitrogen by the protein level in the food. If the result comes out to be 100%, it means that all dietary protein consumed by your dog turns into protein in the body.

According to the AAFCO, the diet of your dog should contain at least 22% and 18% of dry matter for growth and adult dog maintenance respectively. Additionally, the minimum dietary protein required for a growing pup is 18% dry matter while an adult dog needs 8% dry matter.

Other studies suggest that the minimum amount of protein would suffice since according to them, there are no added benefits if there is an excess protein in your pet’s diet. Hence, a protein content that exceeds a maximum amount of 30% dry matter would not contribute to your dog’s growth and will not be excreted from the body since your dog cannot store protein.

However, there are some pet owners who incorporate low protein diets for the prevention and management of certain diseases from their dogs. A low protein diet is done to help decrease the amount of ammonia present in your dog.

Ammonia is created as a by-product of breaking down protein and is considered toxic to the cells. Therefore, reduction of protein intake, as well as nonessential amino acids, may lower the risks that accompany high ammonia concentration in the body.


Fats are types of lipids that are solid at room temperature. Dietary fats are the most concentrated form of energy in pet food (2.25 times more calories than carbohydrates or proteins) and mainly consist of glycerol and triglyceride with varying amounts of free fatty acids.

Triglycerides are divided into long, medium, and short-chain fatty acids. Essential fatty acids (EFAs) are long-chain fatty acids that cannot be synthesized by the body. Hence, there is a need for the dog to consume foods rich in essential fatty acids. Moreover, omega-6 and omega-3 fatty acids are two of the most important polyunsaturated fat.

Some roles of dietary fat include providing energy, help facilitate absorption of fat-soluble vitamins, and the production of the EFAs. At the cellular level, EFAs help against inflammation and provide your dog healthy coat and skin.

Although extremely rare, deficiencies in fatty acids (like linoleic acid) may result in stunted growth, heightened skin problems, decreased rate of wound healing, as well as dull and dry coat. Too much fat consumption, however, may lead to increased body fat volume (obesity). The requirement of fat for absorption of fat-soluble vitamins is only 1 to 2 percent and anything more than this would be an addition to your dog’s weight.

A Dry Food With Nutrition Label

Sources of fat in dogs include vegetable oils, pork fat, and chicken. These are good sources of linoleic acid. Linoleic acid is the precursor of arachidonic acid, which is an essential omega-6 fatty acid. On the other hand, canola and fish oil are good sources of omega-3.

Omega-3 fatty acids may be recommended by your veterinarian to help deal with inflammation caused by certain medical issues like kidney disease, dermatitis, inflammatory bowel disease, burns, cancers, and arthritis.

Carbohydrates & Crude Fiber

Dietary carbohydrates that are present in commercial dog foods are comprised of low and high molecular weight sugar, starches, cell walls, and dietary fibers. One of the important functions of carbohydrates in your dog is to supply energy. The energy being provided is in the form of glucose (sugar) and is also the main source of dietary fiber. This makes it important in dog nutrition.

Whenever the body needs glucose while it is not available, the body is forced to take away an amino acid for another process in the body. Moreover, carbohydrates also function to generate heat in the body, form the base of other nutrients and can be converted into fat.

Carbohydrates are vital when energy consumptions are high. To attain a high-energy input, the processes would include gestation, lactation, as well as the dog’s growth. A growing adult dog with a high-energy requirement should have a complete and balanced diet with at least 20 percent carbohydrates.

Carbohydrates in commercial pet foods can be broken down into three categories; simple sugars, polysaccharides, and oligosaccharides. These three equally play a crucial role in your dog’s complete and balanced diet.

Corn, rice, barley, wheat, potatoes, oats are good sources of polysaccharides (starch) for dogs. Polysaccharides are also known as complex carbohydrates which can be further defines based on how most dogs’ bodies digest the nutrients.

A Puppy Food For Calcium Absorption And Rich In Trace Minerals

There is no such thing as a bad source of carbohydrates for high-quality food. Rather, you can categorize them based on how they are digested by the dogs. Depending on its digestibility level, wheat & rice bran, and apples are good sources of carbohydrates for your dog.

The AAFCO does not have any specifics regarding carbohydrates requirement because of the traditional preparation of commercial diets. Moreover, commercial dog foods have enough carbohydrates to maintain the level of glucose in your dog’s body which is important in maintaining the dog’s nervous system and keep it functional. Grains including oat, wheat, barley, rice, and corn, provide the bulk of starch in dry food, which usually contains 30-60% carbohydrates.

On the other hand, fiber is an analogous carbohydrate or simply the edible part of the plant that is resistant to digestion and nutrient absorption. Fibers are key to dog nutrition for effective gastrointestinal function. It also keeps your dog’s colon healthy and balanced with the microorganism inside the gut.

Although fiber has no dietary requirement in dogs, it has specific health benefits if incorporated into dog nutrition. Elevated levels of fiber in your dog’s diet significantly increases fecal output, alter microflora and fermentation patterns, normalize transit time, and adjust glucose absorption and insulin kinetics.

Soluble & Insoluble Fibers 

Total dietary fiber is also made of both soluble and insoluble fibers.

Soluble fibers are fermentable fibers that can be used as an energy source of bacteria in a normal dog’s gut. These fibers retain water and which makes your dog’s feces softer as compared to a dog’s feces that do not have fiber in their diet. It produces short-chain fatty acids that are utilized by the cell inside the intestine as a source of energy (prebiotics) for metabolic processes. Common sources of soluble fiber, in commercial dog foods, are fruits and gums (viscous polysaccharides from plants and plant seeds).

Conversely, insoluble fibers from grains, act to increase the fecal bulk but do not soften the dog’s fecal output. Unlike soluble fibers, insoluble fiber does not absorb water and is added to the diet of your dog as cellulose.

Fibers are typically considered as supplements to the actual dog diets and are sometimes used to manage medical issues in dogs like diabetes mellitus, facilitation of weight loss, and other gastrointestinal issues.

Canned Pet Foods For Fluid Balance


A nutrient must possess these characteristics in order to be considered a vitamin:

  • It is essential in small amounts to achieve normal function.
  • It causes a deficiency or lessens normal functioning when it is lacking.
  • It is required to complete a diet.
  • It is an organic compound that is neither fat, carbohydrates nor protein.
  • It can’t be naturally synthesized to be sufficient to support the normal function of the body.

Vitamins are used for a variety of functions in your dog’s body including DNA synthesis, clotting of the blood, eye function, neurologic function, as well as bone development.

The consumption of vitamins over the recommended dose of AAFCO can lead to complications and toxicity. Likewise, deficiency in a specific vitamin can result in an incomplete reaction of multiple vitamins that can cause cascading issues.

Meat-based Food Rich In Folic Acid For Your Dog's Nutritional Needs

It is necessary to monitor your dog’s diet with the different sources of vitamins as vitamin excess and deficiencies may occur from the inconsistencies of raw diets like organ meats (liver, lungs, heart, etc.). Hence, the use of supplements is highly suggested to ensure the proper amounts to take. Although dogs can synthesize their own Vitamin C, you may provide supplementation which functions as a free radical scavenger.

Most of the commercial pet foods available in the market are fortified with vitamins beyond the minimal level. Moreover, you should know that the vitamins required to be present in your dog’s food are categorized into two: fat-soluble vitamins & water-soluble vitamins.

The fat-soluble vitamins include vitamin K, vitamin D, vitamin A, and vitamin E. They have the highest risk for deficiency and toxicity and they require bile salts and fat to be absorbed by dogs. Meanwhile, water-soluble vitamins are readily absorbed and used by the dog’s body.

Vitamin A

It is also known as retinol and it is important for normal vision, reproduction, growth, healthy skin and support your dog’s immunity. The AAFCO recommends 5000 IU/kg of Vitamin A dry matter for all types of food (puppy food, adult food, and senior food.)

Lack of vitamin A may lead to night blindness, weight loss, stunted growth, dull coat, and immune system issues while over-supplementation can cause abnormal bone growth and bleeding. To achieve nutritional requirements, you may give your dog natural sources of vitamin A like egg, liver, dairy products, and fish oil, as recommended by your vet.

Vitamin D

Also known as cholecalciferol and ergocalciferol, vitamin D is essential for intestinal absorption and sustenance of calcium and phosphorus levels in younger and older dogs alike. The AAFCO recommends 500  IU/kg DM of Vitamin D for dogs for all life stages.

Natural sources of this vitamin include marine and freshwater fish, beef, eggs, dairy, as well as liver, as advised by your vet. Vitamin D deficiency may lead to rickets, enlarged joints, and osteoporosis in older dogs. On the other hand, toxicities can result in hypercalcemia, weight loss, and lameness.

Vitamin E

It is also called alpha-tocopherol. Vitamin E functions as an antioxidant for your dog. Deficiency in vitamin E may lead to anorexia, immunity issues, and neurological concerns. Seeds, cereal grains, and vegetable oils are the most abundant natural source of vitamin E. According to the AAFCO, it is recommended that a dog consumes 50 IU/kg DM of Vitamin E a day.

Vitamin K

Also known as menadione, vitamin K is involved in bone development and blood clotting. The deficiency of this vitamin may lead to hemorrhage and prolonged clotting. This may occur due to some medical conditions that impair vitamin absorption in the gut.

Oilseed meals, alfalfa meals, liver, and fish meals are the main natural sources of vitamin K. The AAFCO has no recommended requirement for vitamin K in dogs.

B Complex

Vitamin B complex is composed of eight B vitamins namely: thiamine, niacin, riboflavin, pyridoxine, pantothenic acid, folic acid, biotin, and cobalamin.

Vitamin B complex acts as a co-enzyme that promotes biochemical reactions to turn carbohydrates into glucose that is used as energy for the body. It is water-soluble so the vitamins are flushed through the body in around eight hours. Deficiency of this vitamin includes excessive hair loss, anxiety and stress, increased cholesterol levels, decaying teeth, flea allergies, and constipation.

Feed Your Dog With Foods According To His Dietary Needs



100mg/Mcal of macro-minerals are required to be in your dog’s nutrition.

  • Calcium– It maintains the shape of the bones and the teeth of dogs and is important in cell communication, blood clotting, muscle function, and nerve transmission.
  • Phosphorus-It is the second structural component of bones, teeth, DNA, and RNA. It is also vital for cell growth, amino acid, protein formation, and cell energy use.
  • Magnesium– It plays a role in the metabolism of fats and carbohydrates and is a part of neuromuscular activity. It is also involved with the composition of bones. Some of its sources are soybean meal, and bone products.
  • Potassium– It maintains the acid-base & osmotic balance, nerve impulse transmission, and muscle contractility.
  • Sodium & Chloride-It maintains acid-base balance, and osmotic pressure in your dog’s body. It is also needed for the absorption of calcium and water-soluble vitamins.

Trace Minerals

These are also known as microminerals and 100mg/Mcal of them is required in your dog’s daily diet.

  • Iron-It is vital in the transportation of oxygen. The lack of this mineral can cause anemia, lethargy, stunted growth, and rough coat.
  • Copper-It is needed for hemoglobin function, bone & myelin formation, development of connective tissues, and immune function.
  • Zinc-It is involved in enzymatic reactions, synthesis of protein, and carbohydrate metabolism.
  • Manganese– It is important in carbohydrate and fat metabolism, as well as cartilage and bone development.
  • Selenium– It is responsible for protecting cells from damage caused by oxidation, and is involved in the normal function of the thyroid.
  • Iodine-It is important for the proper function of the dog’s thyroid, which is responsible for body temperature regulation, growth and development, and neuromuscular function.
A Dog Requiring Vitamin Supplementation

What To Look For In A Dog Food

AAFCO Guidelines

Association of American Feed Control Officials (AAFCO) is a nonprofit, private organization that determines the ingredients used in both animal food and pet food. This organization helps to make sure that animal feed and pet food products that your dog eats have undergone thorough analyses and contains the nutritional requirements needed for optimum growth.

With the help of AAFCO, pet parents will know and identify products that would provide your dog’s daily minimum dietary requirement by having a nutritional adequacy statement.

There are eight things that must be included in your dog’s pet food labels:

  • Ingredient statement
  • Dog food product and brand name
  • Ingredient statement
  • Feeding directions (like feeding schedule, amount, and etc.)
  • Address and name of distributor and manufacturer
  • Nutritional Adequacy Statement: This is an indication that the dog food contains a balanced and complete diet for specific life stages of your dog. Factors include growth, adult maintenance, reproduction, as well as whether it is intended for supplemental or intermittent feeding only.
  • Specifications regarding the species for which the pet foods are intended.
  • Analysis report: A complete list of the percentages of each nutritional value in the dog food.

Additionally, the AAFCO requires six essential nutrients to support body functions in dogs namely: water, vitamins, minerals, fat, carbohydrate & fiber, and protein, as discussed above.

Energy Requirements

It is vital to meet the specific daily required energy to sustain your dog’s lifestyle. The energy requirements generally depend on many factors which include: reproduction, growth, life stages, activity level, medical or behavioral issues, and breed.

Raw Foods Rich In Vitamins And Minerals

Water Requirements For Dogs

Since water plays a vital role in dog nutrition, it is considered the most important nutrient that you should incorporate into your pet’s diet. The functions of water include, and are not limited to the following: keeping a healthy nervous system, joint lubrication, dog’s body temperature regulation, providing body structure and shape, keeping eye shape, and facilitation of carbohydrates, fats & protein breakdown.

Generally, the average daily water requirement for healthy dogs is 2.5 times the total amount of dry matter in your dog’s diet. Additionally, the amount of water that your dog should consume daily should be equal to the amount of energy (food), your dog consumes in a day. However, this depends on many other factors that affect your dog’s body, like age, size, gender, diet (food volume), etc.

Water can be easily added to your dog’s diet. So, as a rule of thumb, a dog that eats wet or moist food will drink lesser water in the course of the day because of the dog foods’ high moisture content. Finally, your dog should have a constant source of potable water and have a well-monitored daily water intake to notify your dog’s veterinarian if needed.

A Dog Drinking

Life-Stage Dog Nutrition

Nutrient Requirements For Puppies After Weaning

The transition from the mother’s milk to puppy food can typically begin as early as 3-4 weeks. Helping your pup to get used to solid food is important and as veterinarians would recommend, you could use warm water to wet the puppy food you wish to give your pup to make the food soupy.

Take note that when the transition takes place, the ability of the pups to digest lactose (milk sugar) will be lost, and giving your pup milk may cause gastrointestinal issues. Whether you have small breeds or large breed puppies, they require twice the energy intake of adult dogs. They will also need a diet that contains 25 – 30 % protein for optimum growth. Make sure not to overfeed your pups as they may develop health problems.

Feeding Adult Dogs

The basis of feeding your adult dog should be based on his size and energy level. Simply put, a dog doing normal activities requires “maintenance food” energy. The immobile pampered lapdogs require fewer calories while an active pet requires maintenance plus 20 to 40% of calories.

As pet owners, you may experiment with the amount of food you give to your adult dog and incorporate some human foods that are safe for their consumption as long as you have the supervision of your pup’s veterinarian.

External factors including the ambient temperature may be a factor in how much your dog should be eating. Coping in a cold or hot environment requires energy that your dogs get from the food they eat.

Working canines, including guide dogs, sheepdogs, cattle dogs, and police dogs need an increased amount of food to cope with the stresses brought by work. Depending on the strenuous task given, a dog may need a 40% energy increase when working with a moderate workload, while a high workload requires extra energy of 50-70 percent.

Giving treats to your dog should also be in moderation, roughly five percent of your dog’s daily food intake. So, when using treats as a reward during training, consider using smaller pieces.

A Puppy Milk Containing Beneficial Bacteria

Adult dogs should be fed twice a day, with an interval of eight to twelve hours. Have two feeding schedules in a day, make sure to divide the required daily amount for your dog by two meals and prevent overfeeding.

Other methods that you may employ when feeding your adult dog include portion control feeding, timed feeding, and free-choice feeding.

Portion control feeding is the method where the amount of food that your pet consumes is being controlled by measuring the amount of food you give to your pet. This method is popular for controlling your dog’s weight and for those who might overeat if feed freely.

Timed feeding, on the other hand, refers to the method of giving a portion of food for the pet over a specific period of time. For instance, you placed food in your dog’s bowl for 40 minutes. After the allotted time, the food should be removed if it was not consumed by your dog.

Finally, free-choice feeding involves allowing your dog to eat at any time as his food is readily available. Commonly, free-choice feeding is employed to nursing mother dogs.

Feeding Senior Dogs

Age-related changes in dogs usually start to show around seven to twelve years. These changes may include immunologic, metabolic, and body composition changes which are avoidable and can be managed.

When feeding your senior dog, make sure to have the goal to maintain health and optimum body weight, minimize diseases, and slow down chronic disease development. As your dog gets old, he may experience some health issues like deterioration of the skin and coat, decreased muscle mass, gastrointestinal issues, obesity, dental issues, weakened bones and joints, and impaired immune system.

Smaller dogs have relatively longer lives than large breed dogs. With that said, size is commonly used as an indicator of when to give your dog a senior diet.

The following are rough estimates of the sizes (weight) of dogs turning to senior age.

  • Small breeds weighing <20 lbs- 7 years old
  • Medium breeds weighing 21 to 20 lbs-7 years old
  • Large breeds weighing 51 to 90 lbs- 7 years old
  • Giant breeds weighing >90 lbs- 5 years
Feed Your Dog With Senior Diets Based On His Dietary Needs

Never give your dog a senior diet where protein content is reduced. It is essential to give your old dogs foods that contain optimum levels of digestible portion to maintain healthy muscle mass. Studies suggest that the required protein in older canines does not decrease as they grow old. Likewise, protein does not cause the development of kidney failure.

The dog’s body composition inevitably changes which may be caused by a change in metabolic rate or reduced expenditure change. This may contribute to your dog’s progressive increase of body fat despite the reduced calorie intake. Nevertheless, you still have to give your dog a low-calorie and high protein content dog food to avoid gaining more weight and maintaining muscle mass at the same time.

Your dog’s aging is accompanied by the requisite supplementation of Gamma-linolenic acid (GLA) and fructooligosaccharide (FOS). Although GCAs are naturally synthesized in your dog’s liver, their production level diminishes as soon as the dog ages. GCA is needed to maintain healthy skin and a shiny coat. On the other hand, as aging affects the dog’s intestinal bacteria, it is important to take FOS supplements in order to promote the growth of the intestinal bacteria.

Give your dog antioxidants like Vitamin E and beta-carotene that may help against free radical particles which damage body tissues and may lead to heightened signs of aging. It may help boost the immune system of aging dogs. That’s why it’s important that you give your canine foods that contain a high level of antioxidants.

To assess whether there is progressing chronic disease, your dog should have frequent veterinary visits. Follow a daily routine and stick with it as abrupt changes in daily routines may become a stressful circumstance for your dog.

Senior Diets To Feed Your Dog

Frequently Asked Questions

Why is canine nutrition important? 

Canine nutrition is important in providing the overall boost to your dog’s immune system and improved health over time. Well-balanced nutrition will prevent your dog from acquiring diseases caused by any deficiencies of a specific nutrient.

What food has the most nutrients for dogs? 

There is no one specific food that contains all the nutrients that your dog needs. However, you may choose from various sources and incorporate them with your dog’s diet. Aside from food supplements, you can choose different food source that is rich in one specific nutrient and pair it with another, just make sure the this would no exceed the limit imposed by AAFCO and is advised by your veterinarian.

What nutrients are bad for dogs? 

No nutrients are bad for your dogs. However, if one nutrient exceeds or is lesser than the standards set by the Association of American Feed Control Officials (AAFCO), this may lead to complications caused by deficiencies or oversupply of a specific nutrient. Always consult your vet for the appropriate amount your dog should take and what specific nutrient is missing in your dog.

How do you make sure my dog is getting enough nutrients? 

Feeding your dog with quality dog food will make sure that your dog is getting enough nutrients to sustain body function. You may also want to add a few safe fruits and vegetables to give your dog the vitamins and minerals that they need. Additionally, you may include food supplements just to make sure that your dog is getting enough. Just make sure to talk to your vet on which fruits and vegetables are safe and harmful to your dog and what proper food supplements should they take.


As pet parents, caring for a dog is undeniably hard. When deciding on the best food for your canine friend, it’s imperative that you’re putting all effort into researching the food you feed to them.

While this guide provides ideas and insights about dog nutrition, it is still best that you talk to an animal professional to first know your dog’s health status, whether they need a special diet, or what type of nutrients do they lack. If there is none, you can proceed to have your pup’s food customized uniquely for your dog alone.

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