Dog catching a kibbleCarbohydrates for dogs are a necessary food component. Some people may find this strange, but if you continue reading you’ll find out about the different types of carbs and their different functions.

Though your dog can convert some protein’s amino acids to carbs, his body will function much better when carbohydrates are readily available in his dog food. Based on the molecular structure these nutrients either deliver energy or fiber.

More commonly used names for carbohydrates are sugars, starches, and cellulose.

Active dog in waterSugars and starches can readily be broken down by your dog’s digestive system into the basic building blocks, making them small enough to be absorbed and put to use.

This is not the case for cellulose which is only found in vegetable sources.

Dogs don’t have the required enzymes to digest cellulose unlike herbivores, such as cows and deer. So for a dog, cellulose is a non-digestible carb that we then call a filler ingredient when it’s present in dog food.

Filler carbs, or better called ‘dietary fiber’, do have a function though which you will find out if you continue reading.

Functions of carbohydrates for dogs


Carbs deliver energy just as proteins and fats do. It is the fuel for your dog which keeps him going. Energy requirements differ by life-stage and age, by activity level and even by outside temperature.


The smallest carbohydrate is glucose. Enzymes will digest and break down other carbs to this small molecule. Only glucose is small enough to cross the blood-brain barrier and as such, it is the only nutrient available to that grey thinking matter inside your doggie’s head.

Despite its necessity, there is no need to add glucose to dog food! Glucose is the result of digestion of protein and carbohydrates such as starches, which do need to be present in the canine menu. However, glucose is sometimes added to the dog food recipe for palatability reasons (in other words: to make it taste better).

Intestinal Health

Prebiotics (not PRObiotics) are certain fermentable carbohydrates that stimulate the growth of beneficial gut bacteria.

Water Regulation In The Intestines

Certain indigestible carbs help regulate water in your dog’s intestines. Dietary fiber also reduces energy intake by diluting nutrients. As such it can reduce the growth rate of your canine. For this reason, light dog food or weight loss dog food typically has higher percentages of fiber.

Should the dog food you’re feeding now be too low in dietary fiber for your pooch then you may notice this by loose stools. When there is not enough fiber, the formation and elimination of feces is affected.

Too much fiber is not good either as it makes digestion and absorption of nutrients less efficient. Stools, in this case, may appear hard and compact. You see? You can tell a lot by looking at dog poo if you just know what to look for.

Different sources of fiber exist and these differ in quality. For instance, cheap weight-reducing dog food can be filled with peanut hulls. This is just for volume purposes; when your dog’s stomach is filled with indigestible crap, he will eat less. Would you eat peanut hulls to stop feeling hungry when you’re dieting?

A better source of fiber is beet pulp since this also delivers carbohydrates.

Building Blocks

Glucose delivers carbon-atoms to construct other organic compounds required in dog metabolism.

More About Their Classification Specific For Dogs

We can distinguish 4 groups of carbohydrates based on their behavior or function in a dog’s body. This classification may NOT be the same for other animals species as they can differ in digestive systems because of genetics.

Absorbable Carbohydrates For Dogs

The smallest carbohydrates are called monosaccharides. These are small molecules that can be absorbed directly without enzymatic processing. Examples are glucose and fructose. These nutrients are present in cereal and legume grains, which you often find in dog food.

Digestible Carbohydrates For Dogs

These molecules consist of two monosaccharides linked together. This bond can be broken by enzymes present in your dog’s intestines, resulting in absorbable monosaccharides. Examples are lactose, sucrose, and maltose.

One remark about lactose: Under certain conditions, there may not be enough of the specific enzyme lactase present in the small intestines to digest it; a condition called lactose intolerance. Lactose is then fermented in the colon (and in that condition classified as ‘fermentable carbohydrate’).

Lactase activity typically decreases with age, which is why puppies and kittens drink milk but not grown-ups. Notice the same difference in sheep, horses, cows etc. Adult dogs with low levels of lactase may suffer from diarrhea when fed a lactose-rich dog diet.

Continue reading about enzymes for dogs »

Fermentable Carbohydrates For Dogs

These carbs consist of multiple mono-saccharides linked together through glycosidic bonds and are called oligo-saccharides or polysaccharides. These escape both absorption and digestion and just pass through the intestines to the colon.

Tip: Certain carbohydrates, called MOS and FOS, are VERY beneficial for your dog’s immune system. They work by inhibiting bad bacteria or promoting good bacteria. Also, the absorption of nutrients is increased which also contributes to good health.

Learn about these functional dog food ingredients »

In the colon these compounds are fermented by microbes; a process that is accompanied by the production of gases. So should your dog be farting a lot, then perhaps he has difficulties digesting certain carbohydrates (for instance lactose) in his current diet. An adult maintenance diet should be limited in lactose content to prevent these difficulties.

Tip: Is your dog farting a lot? Then he could have problems digesting certain food ingredients. Try switching dog food to find a better digestible food for him.

Certain types of these, such as the inulin-type fructans, can be classified as prebiotics. These do more than just passing through as these stimulate the growth of the “good” bacteria in your dog’s intestines.

Non-Fermentable Carbohydrates For Dogs

Examples are cellulose (the stuff plant walls are made of) and wheat bran. These compounds cannot be digested at all and directly contribute to the volume of your dog’s poo. When present in dog food these carbs reduce intestinal transit time.

Cellulose has no nutritional value and does not contribute to the energy amount of the food. For this reason, it can be used in low-calorie dog food as a bulking agent.

Reasons To Modify Carbohydrate Content In Dog Food

Dog food with altered carbohydrate contents is manufactured specifically for the following conditions:

  • Weight control issues and canine obesity.
  • With age, a dog becomes less able to regulate its blood sugar levels. This can ultimately result in canine diabetes.

Pin It on Pinterest