What do dogs need in their diet?
As omnivores, dogs have the ability to digest both meat and vegetables. Therefore they need a balanced diet of proteins, fats, carbohydrates (they are classed as macronutrients) as well as vitamins and minerals (micronutrients). Both macro- and micronutrients are important for healthy body functions, however, it is the macronutrients that provide the foundation of a dog’s (or of course human’s diet). It is important to understand what each macronutirent does to the body, why it is important and what your dog’s needs are for each. We will take you through each of them in turn.
MACRONUTRIENTS
Protein
Protein is extremely important for building and repairing muscles and other body tissues. It is needed to form new skin cells, grow hair, build muscle tissue, and more. It also assists in creating body chemicals like hormones and enzymes that are needed for normal function. It provides energy and keeps the immune system strong.
Proteins are made up of amino acids, and dogs require 22 amino acids to make necessary proteins. A dog’s body is able to make about half of these needed amino acids, but the rest must come from the food your dog eats every day. Because these amino acids are so important, they are called essential amino acids. Deficiencies of any of the essential amino acids over time can lead to health problems.
Animal proteins are complete proteins, meaning they contain all 10 essential amino acids a dog needs ( as well as some non-essential ones). Whilst plants also provide amino acids, there is only a handful which contain all the essential amino acids required in the canine diet.
10 Essential Amino Acids for Dogs
- arginine – needed for healthy circulation and blood vessel dilation
- histidine – improves oxygen circulation for the whole body
- methionine – promotes healthy skin and coat
- threonine – important for energy production
- isoleucine – protein synthesis and muscle development
- leucine – as above
- valine – as above
- phenylalanine – required for thyroid and adrenal gland function
- lysine – aid protein synthesis for growth and development
- tryptophan – supports circadian rhythm so that your dog knows when to sleep
Whilst plants provide digestible protein for energy they do not contain all 10 essential amino acids (with a few exceptions) needed in a canine diet, therefore it is important to provide sufficient meat to your dog for long-term health.
Interestingly, it is also common practice by dog food manufacturers to increase the dog food’s protein content by the inclusion of grains and plants and market them as extremely beneficial due to the added vegetables. However, the truth is that this only helps those manufacturers to keep their manufacturing cost low and their profits high as a dog cannot easily digest grains and/or inexpensive grains and vegetables do not provide all the essential amino acids required. Digestibility of a macronutrient is usually discussed with reference to its bioavailability. One fairly inexepensive but highly digestible protein source is eggs. Now check out how many dog food manufacturers use eggs in kibble! There is nothing wrong with using eggs or giving eggs to your dog, however, these manufacturers just distort the true value of their food, whilst asking for a high price on the basis that it is high in protein, has added vitamins and vegetables (more on these added synthetics vitamins later).
Digestibility of a macronutrient is usually discussed with reference to its bioavailability. One relatively cheap but highly digestible protein source is eggs, however, you never find it on the ingredients list! One reason is that it is more expensive than other less bioavailble sources (such as grains or meat meal). Manufacturers usually distort the true value of their food by not detailing bioavailability but just the ingredients regardless if they are easily digestible or not by dogs.
Fat
Fats are very important in both human and canine diets as they are needed for energy production, cell membrane integrity, hormone production, insulation and many more body functions. Fat is also required for the absorption of fat-soluble vitamins, namely vitamin A, D, E, and K. Without enough fat, a dog with an unlimited supply of those vitamins cannot benefit from them. Fat also serves as a source for essential (unsaturated) fatty acids (EFAs) that canines can’t manufacture but they are needed for cell membrane integrity.
There are 2 types of fats:
- Saturated fat, which is easily digestible and provides a great source of energy. Examples include butter, cheese, eggs, beef, salmon, coconut oil or peanut butter and many more. Saturated fat helps the absorption of vitamin A,D,E and K as mentioned above. However, some dogs can’t easily digest cow milk and for them sheep or goat milk products are better.
- Unsaturated fat includes vegetable oils, avocado, nuts and seeds, etc. Remember, that avocado is toxic for dogs and not all nuts are great either. These are detailed further in the article.
Essential Fatty Acids (EFAs)
EFAs are a type of saturated fat and as the name suggests (essential) a dog is unable to synthetise all the required EFAs and therefore they are needed in the diet. There are 2 main categories and altogether 5 EFAs. They all have common dietary sources so eating one source usually provides the rest of the EFAs. For simplicity, in this article we just break them down to the two major groups:
- Omega 3 fatty acids – rich sources include oily fish such as salmon, mackerel, herring, anchovies and sardine, flaxseed, hemp, soybean, walnut, rapeseed and dark green leafy veg are rich in these EFAs.
- Omega 6 fatty acids – rich dietary sources include sunflower seeds and oil as well as safflower oil. Animal products such as meat, eggs are also rich sources of one type of Omega 6 fats.
The ideal ratio
The Western human diet is rich in Omega 6 fatty acids and as such the ratio between Omega 3 and Omega 6 fatty acids tends to be around 10:1 (the ideal ratio is 1:1-3)! More and more dogs’ diet mimics their owners therefore their ratio can be distorted, albeit dogs do need a larger amount of meat in their diet and therefore they need more Omega 6. The ideal ratio for dogs is:
Omega 3:Omega 6 = 1-5:1:10
Kibble is often fortified with EFAs, however, this can actually cause issues for some dogs, plus manufacturers don’t always detail which type of EFAs were added to the food and in what ratio.
As well as the ratio, the source of fish oil is also important to consider. Fats and oils from poor sources will adversely impact a dog’s health. You also need to be careful with supplements as excessive Omega 3 supplementation can suppress the immune system, risk mercury accumulation and oxidative damage. In order to know more about the topic, please read Supplements for Dogs.
Carbohydrates
Carbohydrates do have a place in a dog’s diet but not all carbs are equal. When it comes to carbohydrates, we usually talk about 4 sub-categories:
- Digestible
- Absorbable
- Fermentable – this type of carbohydrate is required to feed healthy bacteria in the intestines. Fermentable carbs are also known as prebiotics and they are often present in commercial dog food in the form of chicory root. Whilst they are healthy, it is not advisable to overfeed them
- Non-Fermentable carbs are basically fibre, which is essential for healthy digestion and regular bowel movement. Fibre cannot be digested, however, it slows down digestion and keeps dogs (and humans ) fuller for longer. Specifically, it is soluble fibre refers which does this by attracting water and giving the feeling of fullness. On the other hand, insoluble fibre adds bulk and speeds the movement through the digestive system. Brown rice is a good example of insoluble fibre.
Vegetables are great sources of fibre and they also provide vitamins and minerals therefore it is great to incorporate them into the diet.
Simple vs. complex carbs
Another way to group carbohydrate is simple versus complex carbs.
Simple carbs have very low nutritional value other than they give a quick boost of energy, which doesn’t last long. Simple carbs are made up of one sugar molecule, like glucose or fructose and simple carbs often refer to the likes of white bread, pasta, cake, sugar, fruit, etc.
Complex Carbs take much longer to digest and they provide a slow-releasing form of energy, which will maintain the blood sugar level at a healthy level for longer. They are made up of several sugar molecules, which the body has to break up in order to digest and this takes some time hence the slow-releasing energy. Complex carbs, like brown rice, usually contain fibre and other nutrients as well, making them a healthier choice.
MICRONUTRIENTS
The word micronutrient encompasses vitamins and minerals, which are still essential for a dog but they are needed in much lower quantities.
VITAMINS
Vitamins play an important role in immunity, energy production, and many more. They can be sub-categorised into water- and fat soluble vitamins.
Vitamins are abandunt in fruits and vegetables. Whilst vitamins are added to commercial dog food, they are usually the cheap, synthetic version, making them difficult to absorb. As such, it is advisable to incorporate fruit and veg into your dog’s diet (Please read our article , Vegetables for Dogs to know which veg to feed to your dog to be on the safe side).
Vitamins are organic and can be broken down by heat, air or acid.
MINERALS
Minerals are important for healthy cell function, growth, repair and many more. They are found in both animal and plant origins.
Macro minerals are required in larger amounts than the trace minerals and are found in greater amounts in your dog’s body. Macro minerals include calcium, phosphorus, magnesium, sodium, chloride, potassium and sulphur. Trace minerals include iron, zinc, copper, chromium, iodine, selenium, manganese and fluorine.
Significant interactions exist between many of the minerals. Thus, minerals need to be balanced with each other to provide optimal health. Too much of one mineral and not enough of another can affect growth and cause other problems in the body. Problems with mineral nutrition in dogs are often a result of excess of imbalance from interactions with other nutrients. Supplementing your dogs food with minerals should never be done without expert advice. The health risks from excessive amounts or improper balance are too severe
A word on ’ash’
When a food is analysed for energy all nutrients other than minerals are removed. The remaining material is made up if minerals, commonly referred to as ‘ash’ – also one of the most frequent misunderstood terms in dog food. High quality dry food generally contain between 5%-8% ash.
Summary on Dogs’ Nutritional Requirements
Dogs nutritional needs is similar to humans. As omnivores, they need healthy sources of protein, carbohydrates, fats, vitamins and minerals. As a nutritionist, I believe it is better to provide all of these in the most natural form, therefore as food which the body can easily absorb and digest as opposed to synthetic versions found in supplements. However, supplementation can be a good idea should your dog be severely deficient.
Hopefully the above information will guide you choosing the right food for your beloved dog. Should you wish to cook for your dogs or address nutritional deficiencies, it is best to speak to a pet nutritionist.