Do Dogs Need Carbohydrates? Carbs in Dog Food Explained

By Tailwisp Editorial TeamUpdated October 17, 20263 min read

Carbohydrates are often cast as the bad guys of the pet food world. But the biology is more balanced. Dogs are not wolves, and they can make good use of cooked starch. The details matter though, so here is what to know.

What carbohydrates are

Carbohydrates include simple sugars, starches and fibres. In dog food, they come from ingredients such as rice, corn, wheat, oats, barley, potatoes, sweet potatoes, peas and lentils. They provide energy and, in the case of fibre, support digestion. See our guide to fibre for dogs.

Do dogs need them?

Dogs have no minimum dietary requirement for carbohydrates, as they can make glucose from protein and fat. But carbohydrates are an efficient, inexpensive energy source, and cooked starches are well digested by most dogs. Compared with wolves, dogs have extra copies of genes for starch digestion, a result of domestication.

Digestibility

Raw starch is poorly digested, so cooking and processing matter. Well-cooked grains and potatoes are highly digestible. Some carbohydrate sources, such as legumes, contain more fibre and protein. Digestibility varies by source and processing.

Common carbohydrate sources

• Rice: Highly digestible, used in sensitive stomach diets.
• Oats and barley: Provide fibre and slow-release energy.
• Corn and wheat: Common and digestible when cooked, though some dogs are sensitive.
• Potatoes and sweet potatoes: Starchy and digestible.
• Peas, lentils and chickpeas: Add fibre and plant protein, but have been discussed in relation to heart disease concerns. See our guide to grain-free dog food.

Estimating carbohydrate content

Pet food labels list protein, fat, fibre and moisture but not carbohydrate. You can estimate it:

1. Add crude protein, crude fat, crude fibre, moisture and ash. If ash is not listed, estimate around six to eight percent for dry food.
2. Subtract the total from one hundred.

The result is the approximate nitrogen-free extract, mostly starch and sugar. Convert to dry matter to compare foods. See our guide to reading a dog food label.

Carbs and weight

Calories matter more than macronutrient ratios for weight control. Starchy foods are not fattening by themselves, but calorie-dense diets and overfeeding are. See our guide to dog obesity.

Carbs and diabetes

Dogs with diabetes need consistent meals and often a diet with controlled starch and good fibre. This must be directed by a vet.

Protein, fat and carbs together

A balanced diet depends on the combination, not any one nutrient in isolation. See how much protein dogs need.

Low-carb and high-carb marketing

Some marketing frames low-carb diets as superior. Evidence for general health benefits in dogs is limited. Choose a diet that is complete, suits your dog and maintains healthy weight.

Treats

Treats and table scraps can add many carbohydrate calories. Keep treats under about ten percent of daily calories. See healthy dog treats.

A worked example

Suppose a dry food lists crude protein at 26 percent, fat at 15 percent, fibre at 4 percent and moisture at 10 percent. Assuming about 7 percent ash, the estimated carbohydrate is 100 minus 62, which equals 38 percent. That is an average figure for a kibble, since most dry foods contain starch to form the pieces. A wet food with 78 percent moisture and a few percent protein will look very different until converted to dry matter, which is why that conversion matters when comparing products.

When to talk to your vet

Dogs with diabetes, chronic diarrhea, pancreatitis or obesity may need specific carbohydrate levels and fibre types. Do not guess. Ask your vet about a suitable diet, and avoid changing food abruptly. See our guide to switching dog food safely.

The takeaway

Dogs do not need carbohydrates, but they use them well. Focus on overall diet quality, digestibility and your dog's health.

This article is general educational information, not veterinary advice. Every dog is different. If your dog is unwell, or you are unsure about a symptom, diet change or medication, contact your veterinarian.