If you want to start a heated debate with veterinarians, biologists, and canine nutritionists, ask them if dogs can digest carbohydrates.

Depending on who you ask, you’ll get an enthusiastic YES or a resounding NO.

As an animal nutritionist, my answer is…It depends.

Yes, some dogs can digest carbohydrates just fine.

No, not all dogs can digest them in the same amounts, or well.

One reason is because dogs, like humans, have a varying ability to produce enough digestive enzymes that break down carbohydrates to the sugars our cells can utilize. Other reasons include genetics, health status, activity and more.

What are enzymes, and why are they important for dogs?

Enzymes are proteins that help the body break down foods into usable nutrients. They are made by the body in the mouth, stomach, small intestine, and pancreas – but not all areas produce an effective amount. 

Among all of these enzyme factories, the pancreas is the most important. It is the body’s enzyme powerhouse. 

Several factors can influence the efficiency of the pancreas’ enzyme production, including the dog’s age, breed, health status (e.g., diseases like pancreatitis and exocrine pancreatic insufficiency), and genetics. 

There are also variables that can dictate how well an enzyme works, such as temperature and pH. For example, if the body is too hot or cold, or the pH is not within the ideal range, enzymes may not work as well as they should. 

While there are many types of enzymes, below are the three main types:

THE THREE  MAIN TYPES OF DIGESTIVE ENZYMES

Enzyme Type	Macronutrient Targeted	Examples (not comprehensive)	Can be found
Carbohydrase (often called amylases)	Carbohydrates (Sugars)	Amylase, Sucrase, Lactase, Maltase	Mouth, Pancreas, Stomach, Small Intestine
Lipase	Fats (Lipids)	Bile Salt-dependent Lipase, Pancreatic lipase, Hepatic Lipase, Gastric Lipase	Stomach, Pancreas, Small Intestine
Protease	Proteins (Amino Acids)	Trypsin, Chymotrypsin, Carboxypeptidase	Stomach, Pancreas, Small Intestine

 

The digestive enzymes responsible for carbohydrate digestion are called carbohydrases. A small amount of carbohydrase is found in saliva but is not enough to help dogs digest carbohydrates. 

Carbohydrases are produced in large quantities by the pancreas and then excreted into the stomach and small intestine, where they start breaking down carbohydrates (starches and sugars) as part of the digestive process. These carbohydrases are critical to helping dogs digest diets that are higher in carbohydrates (like kibble). 

However, dogs need to have enough carbohydrases available to completely break down carbohydrates in their digestive system. 

The primary cause of a dog not producing enough carbohydrases is genetics. This is because each type of carbohydrate has one or more genes associated with enzyme production. The dog will have difficulty digesting certain carbohydrates if there aren’t enough genes to produce a specific enzyme. 

What makes this complicated is that not all dog breeds have evolved the same regarding types of genes and numbers of gene copies. Even dogs in the same breed (or even litter) have inconsistent numbers of carbohydrase gene copies. 

Researchers in a recent study examined the relationship between amylase activity (a specific carbohydrase) and the relationship associated with higher numbers of AMY2B copies in canines. AMY2B is responsible for the production of pancreatic amylase, which starts the breakdown of starch.

The overarching finding was that the number of AMY2B varies widely among dog breeds but also within individual dogs of the same breed¹.

This is what makes the blanket statement “dogs have evolved to digest carbohydrates” untrue.  

What does all of this mean for your dog when it comes to digesting carbohydrates?

Your dog’s ability to successfully process carbohydrates is largely individualized and complex. That means your pet’s diet and nutrition deserve an individualized approach. It also explains why some diet types and food formulations work really well for some dogs and not for others – even dogs from the same lineage!

Even though the dogs share the same genes, they don’t always share the same number of genes that helps them successfully digest carbohydrates.

This is yet another example of why some diets, supplements, medications, etc work for some pets and not for others. We’ve all heard of littermates eating the same diet, with similar exercise patterns, and one of them is obese! This is because each animal (and person) is an individual and diet should be approached as such!

REFERENCES:

1. Arendt M, Fall T, Lindblad-Toh K, et al. Amylase activity is associated with AMY2B copy numbers in dog: implications for dog domestication, diet and diabetes. Anim Genet 2014;45:716-722.