What is a Balanced Diet for Dogs?

Just like us, dogs need a balanced diet for full health and vitality. Providing a dog with ad lib access to water and a balanced complete diet is vital to maintain health and prevent illness and is one of any animal’s five welfare needs according to the law (the Animal Welfare Act, 2006).

Many complete dog foods are just that; so long as fed according to the manufacturer's feeding instructions, they provide a dog with all the nutrient’s they require to maintain full health and vigour. These nutrients are just like those in our diets but are required in different amounts for different animal species and different life stages (e.g. growth, gestation, old age). They can be divided into macro-nutrients (e.g. protein, fat, fibre) and micro-nutrients (e.g. vitamins and minerals).

Dogs come in many shapes and sizes, what we recognise as breeds. Feeding a chihuahua would appear to be very different to feeding a great dane because of the amount of food each would need daily, however, apart from their daily energy requirements (chihuahua a little, great dane a lot!), the food you feed them would be quite similar.

All today’s domestic dogs originate from their omnivorous ancestor the wolf; they have the same monogastric digestive system (meaning single stomach), the same comparative digestive anatomy, and (for the most part) the same physiological requirements for baseline nutrients in their diets. This means that no matter their size all dogs require the following nutrients to form a balanced diet…

Proteins and Amino Acids

Proteins are comprised of amino acids which are the building blocks of all cells and is required for growth, repair and replenishment of cells around the body. Those amino acids which cannot be synthesized by the body are known as essential amino acids and must be provided in the diet. These consist of arginine, histidine, isoleucine, leucine, lysine, methionine, phenylalanine, threonine, tryptophan, and valine. 

Fat and Fatty Acids

Dietary fats (also sometimes known as lipids) are a source of energy in a dog’s diet, they also play a function in maintaining cell membrane stability, in producing steroid hormones within the body, and in maintaining a glossy coat and waterproofing in the fur and skin. Essential fatty acids (EFAs) are called essential because they cannot be synthesized in a dog’s body so must be provided in the diet.  Some examples of EFA’s that should be provided in a dog’s diet include omega 3 and omega 6 fatty acids.

Carbohydrates and Fibre

Dietary carbohydrates include starches, sugars, polysaccharides and fibres. They are primary sources of energy for omnivores such as humans and dogs. Simple sugars (such as glucose) should be avoided in a dog’s diet but can often be found in cheaper pet foods because they are palatable, offering a sweet taste just as they do in human food. The fibre in a dog’s diet can provide the benefit of satiety and regulate stool quality; its presence in a diet is associated with maintaining a healthy weight. 

Water

Water should not be forgotten as an important nutrient in a dog’s diet. When given ad lib access to clean fresh water, healthy dogs can self-regulate their intake to ensure their needs are met. Water has many vital roles in the canine body, indeed 60% of a healthy adult dog’s body weight comes from water; water being a major component of blood and inter- and intracellular fluids. Water allows a dog to regulate its body temperature and allows respiration, urination and defecation. Dehydration can result in a myriad of problems, some of which include difficulty passing faeces, a lack-lustre coat, and heat stroke. 

Vitamins

Some of the vitamins a dog needs in a balanced diet include:

• Vitamin A - Supports healthy vision, appetite, and skin and coat health. Natural beta carotenes also have antioxidant activity. 
• The Vitamin B Complex - Linked to efficient energy conversion from food, the metabolism and efficient nervous system functioning. 
• Vitamin C - Also referred to as ascorbic acid, vitamin C is a water-soluble vitamin that is produced naturally in the dog’s liver and is, therefore, is not strictly required in the diet. It provides protection from free-radical damage, joint health and immune support. 
• Vitamin D - Regulates and promotes the absorption of calcium and calcium balance, which is necessary for skeletal health and development. Thought to have roles in immunity and gene transcription.
• Vitamin E - Sometimes referred to as tocopherol. Vitamin E acts as a powerful antioxidant in the body and is also essential for reproduction, immune function, utilization of vitamin K in the body and red blood cell formation.
• Vitamin K - One of the only vitamins aside from vitamin D that can be generated within the body, it's needed for blood clot formation in the body.

Minerals

Just as with the vitamins, each mineral has numerous roles in the body, and all are required to maintain health. The functions listed below are just some of those functions.  

• Calcium – The most abundant mineral element found in a dog’s body. It is important for skeletal growth and maintenance, and nervous system health. It should be balanced in the diet with phosphorus at a ratio of between 1:1 and 2:1 for optimal health. 
• Phosphorus – Also important for the health of the skeletal system, to be fed in balance with calcium at the ratio stated above.
• Magnesium – Plays a role in the stability of muscle and nervous tissues, hormonal regulation and the structure of bones and teeth.
• Sodium – An important component of inter- and intracellular fluids for conducting electrical impulses around the nervous system. It also helps maintain osmotic pressure in the body.
• Potassium – An important component of intracellular fluid, and also important for bone health.
• Chloride – Found in the extra-cellular fluid of most mammals. It is important in maintaining osmotic regulation and acid-base regulation in the body.
• Trace Minerals - Although found in much smaller quantities than the macro minerals, trace minerals in the body provide equally important roles in maintaining a dog’s health and are therefore required in a balanced diet. The trace minerals include iron, zinc, copper, manganese, selenium and iodine.

Ingredients

As the domestic dog is classed as an omnivore (i.e. eating meat and plants in their diet), there are a variety of ingredients that crop up in commercial dog foods. These range from meats and fish, to grains and veg, even insect-based proteins, bacteria, yeast and algae!

Part of the reason domestic dogs evolved as omnivores were their advantageous nature as scavengers meaning they could live alongside early human settlements and benefits from any available food scraps provided. As such their digestive systems are relatively flexible and good at adapting to eat different kinds of food – hence the variety in today’s pet food market. Some dogs may have food preferences or allergies just like their human counterparts, but most are relatively good at maintaining their health on complete and balanced dog food.

Pitfalls of an Unbalanced Diet

While most people might think deficiency of a nutrient is the most common problem with unbalanced diets, the most common issue with unbalanced diets in the UK is canine obesity. Overfeeding a dog and supplying it with more energy (calories) than it needs daily is providing it with a diet that is not balanced. Weight gain leads to obesity and this alongside associative secondary health problems (e.g. diabetes mellitus, cancer, joint pain) means it’s one of the top three welfare concerns for companion animals in the UK. 

For more information on obesity in dogs or for how to help your dog lose weight why not take a look at these articles [LINKS]

References:
National Research Council. 2006. Nutrient Requirements of Dogs and Cats. Washington, DC: The National Academies Press.