Best Sources Of Fiber For Dogs

fiber in dogs

Do you think your dog doesn’t need fruit and vegetables in his diet? That they’re not part of a species-appropriate diet? You might want to think again. Because, even without the vitamins and minerals these foods bring, the value of dietary fiber alone is essential to your dog’s health.

What Is Fiber?

Fiber is a type of carbohydrate that passes through the small intestine. Digestive enzymes can’t break it down so it remains undigested. Once in the colon, the resident bacteria digest or “ferment” the fiber, creating gases like carbon dioxide, hydrogen and methane. This also produces important short chain fatty acids (SCFA) like acetate, propionate and butyrate.

Short Chain Fatty Acids (SCFAs)

SCFAs remain in the colon or travel to other parts of the body.

  • SCFAs are a source of energy for the cells in the colon. They’re involved in cell division and help form the protective mucus membrane in the gut.
  • They reduce glucose and cholesterol levels, and protect against metabolic disease and obesity.
  • SCFAs, especially butyrate, help build T cells in the immune system, which reduce inflammation. 

SCFAs get absorbed through the wall of the large intestine and help water pass through. Most of the SCFAs then travel to the liver where they’re cleared. Acetate is eventually used by muscles for energy. Proprionate converts in the liver to a coenzyme used in other functions, and butyrate oxidizes in the intestinal mucosa. Here it’s used as fuel for the colonocytes. These cells make up the colon lining that makes up a large part of the immune system

 Those are some pretty important functions from SCFAs that come from fiber.

Types Of Fiber

Here are a few types of bioactive fibers.

Soluble Fiber

Soluble fiber forms a hydrated mass with water. It’s digestible fiber because it’s fermented in the colon by the beneficial bacteria living there as their main source of food. It forms SCFAs essential in fighting pathogenic bacteria.

Here are examples of soluble fiber:

  • Pectin from fruit
  • Beta-glucan from mushrooms
  • Seaweed
  • Some grains
  • Guar gum, extracted from guar beans
  • Methylcellulose, a chemical compound extracted from cellulose

Soluble fibers also include prebiotics … 

Prebiotics

Prebiotics come in the form of inulin or fructooligosaccharide (FOS) found in fruits and vegetables. They feed beneficial bacteria in the gut like Bifidobacteria and Lactobacilli.

Insoluble Fiber

Insoluble fiber doesn’t get hydrated. It bulks up the food to help it pass through the colon. Cellulose is an example of this type of fiber.  

Resistant Starches

These starches are resistant to enzyme digestion in the small intestine so they’re virtually unchanged when they reach the colon where they form SCFAs.

So … in case you’re still wondering …

Do Dogs Need Fiber In Their Diets?


Yes, dogs need dietary fiber because it breaks down into short-chain fatty acids that provide vital functions related to health. SCFAs are a source of energy, protect the gut lining and support the immune system. And fiber has many more health benefits such as a prebiotic and indigestion.

Fiber is an essential nutrient that has many reasons to be part of your dog’s diet.

9 Health Benefits Of Fiber For Dogs

Here are some important things fiber can do for your dog.

1. Antioxidant Properties

A study found that fiber binds as much as 80% of cancer-stopping antioxidant polyphenols in fruits and vegetables. This protects the antioxidants from being digested in the stomach and small intestine. Fiber then provides safe passage of the antioxidant nutrients to the colon. In the colon they’re released by the beneficial bacteria during fermentation where they protect against disease and cancer. 

RELATED: Learn how antioxidants benefit your dog …  

2. Strengthen The Immune System

Fiber feeds the beneficial bacteria in your dog’s gut. That increases the production of SCFAs, including butyrate. Butyrate helps build T cells in the immune system, and that helps reduce chronic inflammation. It’s inflammation that leads to most diseases. Fiber also feeds lactic acid bacteria. This increases the acidity of the colon to fight the growth of bad bacteria that can lead to disease. 

RELATED: Boost your dog’s immune system with these foods … 

3. May Help Prevent Cancer

Fiber reduces the risk of colon cancer in dogs because it speeds up elimination in your dog’s digestive system. The faster potential carcinogens pass through, the less exposure your dog has to them. And fiber binds to carcinogens.

RELATED: Here’s a special fiber to fight cancer …

4. Aid Digestion

When your dog’s food has higher fiber content, it increases the volume of food and the amount of stool making it flow faster and easier through the gastrointestinal tract. Fiber helps moderate the flow so nutrients and water are better absorbed from the intestines into the blood. And some fibers create mucilage helping food slide through the intestines. Others increase the rate at which the stomach empties while others slow it.

5. Regulate The Bowels

The beauty about things in nature is that they often serve multiple functions … and some can be contrary to each other. Like with constipation and diarrhea. In cases of diarrhea, it can slow the muscular contractions (peristalsis) that push the food through the intestines. And it speeds up the contractions if your dog has constipation. Fiber promotes good colon health and stool quality.

6. Clean The Gut

Fiber does a great job of massaging the gut to reduce inflammation and clean the mucous membranes. Fiber can also bind to toxins in the gut and then eliminate them in the stool. It maintains a healthy balance in the gut, which regulates the bowels and keeps the colon healthy.

7. Manage Weight

Obesity is one of the leading causes of illness in dogs. So show your dog you love him by including fiber in his diet. He’ll feel fuller, get more nutrients and still feel satisfied. Studies support the satiating effects of high protein, high fiber diets. They really work!

8. Control Diabetes

When you add higher amounts of fiber to a diabetic dog’s meals, the flow of food through the digestive tract slows … and so does the absorption of sugars into the bloodstream. This results in a more stable blood glucose level over time. 

Caution: If your dog takes diabetes medications, talk to your holistic veterinarian before you add fiber to your diabetic dog’s diet.

RELATED: How diet can help with your dog’s diabetes … 

9. Improve Anal Gland Issues

When a dog has anal gland issues or trouble pooping, adding fiber to his diet can make things easier. Fiber increases the bulk of the stool, and a bulkier stool can help empty the anal glands. 

RELATED: How to manage anal gland problems in your dog … 

How Much Fiber Do Dogs Need?


There isn’t a set amount for dogs. For people, 25 to 35 grams of fiber per day is average. A dog’s diet should contain no more than 10% fiber to avoid overdoing it. Gauge your dog’s needs and feed accordingly. Aim for 5% and increase or decrease as you monitor his stool.

Now that you know why your dog needs fiber in his diet, here are some ways you can add it.

Best Source Of Fiber

Here’s a list of the best sources of fiber for your dog. This gives you lots of choices so you can rotate them through your dog’s diet to provide extra fiber and a larger variety of vitamins and nutrients as well.

Broccoli

Broccoli has amazing health benefits because it’s high in fiber, vitamins and minerals. It’s a member of the cruciferous family that includes its fiber-rich cousins, cabbage, kale, cauliflower and Brussels sprouts. It’s best to chop them and lightly steam or blend them to make them easily digestible for your dog.

Microgreens

If you want even more of a nutrient and fiber boost than broccoli, add microgreens to your dog’s diet. Microgreens are the first shoots through the ground, and they have more nutritional value than the mature plant. You’ll want to keep them at less than 5% of your dog’s diet as they’re very nutrient-dense.

Berries

Berries do triple duty in your dog’s diet. They are fiber-rich, packed with lots of vitamins and … lots of antioxidants. Blackberries and raspberries are especially high in fiber. Raspberries, blueberries and cranberries have lower sugar content … just don’t overdo it. Plus, too many berries can cause the runs.

Kelp

Kelp is a sea vegetable that’s high in iron and fiber. It’s available as fresh, dried or a powdered supplement. Kelp is easy to add by just sprinkling it on your dog’s food. It’s pretty concentrated so you don’t need much if you’re using a dried form … ¼ to 1 tsp of flakes depending on your dog’s size.

Shiitake Mushrooms

Shiitake mushrooms contain beta-glucan, soluble fiber that makes them great as prebiotics too. Most mushrooms are medicinal but the shiitake has medicinal benefits in addition to tasting great in your dog’s dinner and yours. Fresh shiitakes are fiber-rich and can give your dog a feeling of fullness. Be sure to cook them first. Shiitakes also have lentinan, a beta-glucan that boosts the immune system by increasing killer T cells and NK cells. 

If you’re using a powdered mushroom product as a prebiotic, check the label to see that it’s from whole mushrooms … not just mycelium. Mycelium is only part of the mushroom. It’s grown on grains making it higher in starch and lower in beta-glucans, giving mushrooms medicinal benefits

Leafy Greens

Kale shares its benefits with dogs and people. It’s a great source of fiber as well as iron, thiamine, folate and riboflavin. Other dark leafy greens like spinach or Swiss chard are also excellent sources. Chop them up or puree them to make them more digestible for your dog.

Apples

Apples can be a refreshing high fiber, low calorie treat for dogs. But remember, they do have sugar so you don’t want to overdo it. The skin is fine to eat (filled with antioxidants) but don’t give your dog the core or seeds. 

Carrots

Like apples, carrots are low in calories. Carrots are great for fiber, can help control diarrhea,  and help fill your dog if he’s struggling with his weight. You need to grind or lightly steam them so they’re more digestible. 

Green Beans

Anyone trying to get their dog to lose some weight has probably tried the green bean diet. The idea is to remove some food from your dog’s bowl and replace it with low-calorie, fiber-rich green beans. They’ll help your dog feel full without the calories. 

Pumpkin

Pumpkin is an excellent source of nutrients and fiber. It’s often the go-to suggestion when a dog has digestive issues. You can add pumpkin to your dog’s meal or even freeze it in cubes for a summer treat. If you’re using canned, be sure to get plain pumpkin and not pumpkin pie filling. Start with a teaspoon or less and monitor the results.

Are Raw Fed Dogs Low In Fiber?

Yes, they can be if they aren’t getting fruits and vegetables in their diet. Your dog’s poop is the window to his raw diet. It’s often chalky and white … meaning he’s getting a lot of bone which can lead to constipation.

When his poop is too chalky, he needs more liquid and fiber. And you can feed him as much as 10% of his diet in fiber giving you lots of room to add what’s needed.

How To Know When Your Dog Needs Fiber

As you’ve seen, dogs DO need fiber in their diets. Or sometimes they need fiber for short-term or long-term health issues as you aim for good quality, regular bowel movements.

The first indication that your dog needs fiber is from his stool. If your dog is constipated or has loose stools, either can indicate a need for fiber. When you start adding fiber, you’ll want to ensure your dog gets frequent walks to avoid accidents.

Chronic digestive conditions like exocrine pancreatic insufficiency (EPI) affect the small intestine. When you add soluble fiber, it will slow the flow so nutrients absorb better. A dog with one of these conditions may be under the care of a holistic veterinarian so ask for help determining the amount of fiber.

Is There Enough Fiber In Dog Food?

No, there’s usually not, because the “Guaranteed Analysis” label lists a maximum amount rather than the actual amount. And that makes it pretty much impossible to do a calculation. Plus dog food labels don’t specify the type of fiber. They only report “crude fiber,” which is basically insoluble. And it’s listed as a maximum so it could be any lower amount.

The fiber in different commercial dog foods can also vary dramatically. Even though diets promoted for seniors or weight control are high fiber or fiber-rich foods, they vary a lot. And pet foods often use fiber like cellulose, which is basically sawdust … and has no nutrients. When you compare dry food with wet, dry food lists a higher percentage of fiber than canned because of its water content. Serving for serving, the fiber content of dry kibble and wet food are not very different.

Can Your Dog Have Too Much Fiber?

Even in high doses fiber is usually okay. But if you really overdo it, too much insoluble fiber can decrease the diet’s nutrient value by binding to minerals. It can lead to weight loss, poor coat quality, vomiting, diarrhea and flatulence.

And just as fiber can aid your dog’s digestion and relieve constipation, too much fiber can also cause gas and diarrhea. It’s a delicate balance. 

Fiber is an important addition to your dog’s diet. It’s always best to add fresh foods like those listed earlier. Then in addition to fiber, he’s getting extra nutrients that contribute to his long term health.

References

Andoh A, Tsujikawa T, Fujiyama Y. Role of dietary fiber and short-chain fatty acids in the colon. Curr Pharm Des. 2003;9(4):347-58. 

Lattimer, James M., et al. Effects of Dietary Fiber and Its Components on Metabolic Health. Nutrients. 2010, 2(12), 1266-1289. 

Zeng, Huawei, et al. Mechanisms linking dietary fiber, gut microbiota and colon cancer prevention. World J Gastrointest Oncol. 2014 Feb 15; 6(2): 41–51.

Weber, Mickael, et al. A High-Protein, High-Fiber Diet Designed for Weight Loss Improves Satiety in Dogs. Journal of Veterinary Internal Medicine. Volume 21, Issue 6.

Hilton, John. Carbohydrates in the nutrition of the dog. Can Vet J. 1990 Feb; 31(2): 128–129.

Otles, Semih, et al. Health Effects Of Dietary Fiber. Scientiarum Polonorum. University of Izmir, Turkey. Acta Sci. Pol., Technol. Aliment. 13(2) 2014, 191-202.

Mezes, Miklos, et al. Antioxidant effect of the fibre content of foods. Orv Hetil. 2018 May;159(18):709-712.

Padayachee, A., et al. Binding of polyphenols to plant cell wall analogues – Part 1: Anthocyanins. Food Chemistry. Volume 134, Issue 1, Sept 2012, Pages 155-161.

Alves, J.C., et al. The use of soluble fibre for the management of chronic idiopathic large-bowel diarrhoea in police working dogs. BMC Veterinary Research. Volume 17, Article number: 100 (2021).

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