Carbohydrates for Dogs – Sorting the fact from the fiction

Over recent years we have seen certain trends relating to the carbohydrate content of dog food.

On the one hand we see dog foods that have been formulated to be, ‘low carbohydrate’, like a wolf
would eat (sometimes termed, ‘species appropriate’) or they may have a particular type of
carbohydrate excluded, for example, ‘grain-free’.

On the other hand, the type of carbohydrate in the food may be promoted as ‘wholesome’ or ‘nutrient rich’.

With these opposing views in mind, what is the best option for our dogs?

Do we need to avoid carbohydrate or is it just as case of looking for the best type of carbohydrate in their food? In this article, we will take a look at what carbohydrates are, whether dogs need them and if so, what are their potential benefits.

What are Carbohydrates?

Carbohydrates are found in two forms in foods:

• Simple sugars (glucose and fructose) also known as monosaccharides and can be joined together to form disaccharides.

• Complex carbohydrates (starch) made up of long chains of glucose molecules joined together also known as polysaccharides.

Starch is the main form of carbohydrate found in dog foods. Cereal grains such as corn, wheat, barley and rice are the main ingredients which provide starch.

The body stores starch in the form of glycogen in the liver and muscles where it a readily available source of energy.

Fibre is also a complex carbohydrate, but the body cannot digest it so it has no energy (calorie) value.

However, it does provide benefit in terms of helping to improve stool quality (preventing constipation) and providing a source of nutrition for the good bacteria in the large intestine to flourish therefore creating a healthy gut microbiome.

Do Dogs Need Carbohydrate?

Dogs are omnivores and although they have no specific requirement for carbohydrate, and although they could survive without it, this does not mean that is the best or optimal nutritional situation for them.

Dogs can digest cooked carbohydrate in the amounts that are present in conventional dog foods. In fact, dogs can obtain a large percentage of their energy from carbohydrate on a daily basis. This can be especially beneficial for those dogs who need a medical diet where the amount of fat or protein need to be limited.

The striking genetic difference between dogs and wolves is that dogs have significantly more copies of the gene that codes for amylase, the enzyme produced by the pancreas to digest starch (complex carbohydrate) in a meal.

This study, published in the Scientific Journal Nature in 2013, was ground-breaking because it showed overwhelmingly that dogs have evolved from wolves to be more efficient at digesting carbohydrate.

This is thought to be a direct result of dogs living side by side with humans over the past 10,000 years and sharing their carbohydrate containing diet.

The Benefits of Carbohydrates

Carbohydrate is a valuable source of energy in the diet.
If we consider the energy in carbohydrate compared to fat we can see the potential benefit of
including it in their diet:

We can see that carbohydrate and protein have half the calories for every gram, than fat. Typically,
low carbohydrate diets are high in protein (meat) and fat goes hand in hand with animal protein. By
including carbohydrate, the fat content can therefore be lowered and this can be beneficial not just
for those dogs who need a lower fat diet (senior dogs, dogs with pancreatitis, dogs who are
overweight) but it also makes for a better portion size and helps to keep the dog fuller for longer.

In addition, if adequate carbohydrate is supplied in the diet, protein will be spared from being used a
source of energy and can then be used for growth and repair. This is also beneficial for senior dogs
to help maintain their muscle mass which would otherwise naturally decline with age. If dogs can
maintain their muscle mass with age, they are likely to be able to stay active in their senior years.

Which Type of Carbohydrate is Best?

Different carbohydrates offer different nutritional benefits, they are not simply cheap fillers in a dog
food:

• Oats: rich in soluble fibre and the essential fatty acid, linoleic acid
• Wheat and beans: high in protein and low in fat
• Sweet potatoes: rich in potassium and beta carotene (the body uses it to make vitamin A)

References

Axelsson, E., Ratnkumar, A., Arendt, ML, et al. The Genomic Signature of Dog Domestication Reveals
Adaptation to a Starch Rich Diet. Nature 495, 360-364 (2013). https://doi.org/10.1038/nature
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The Nutritional Requirements of Cats and Dogs: FEDIAF