Why Fibre Matters in Your Dog's Diet

At a glance

• Fibre supports gut motility — the movement of food through the digestive system — and helps prevent both constipation and loose stools
• Prebiotic fibre feeds beneficial gut bacteria, which directly affects immune function, digestion, and mood
• There are two types: soluble fibre (fermented by gut bacteria) and insoluble fibre (adds bulk and keeps things moving)
• Dogs need both types — the right balance depends on the individual dog and their health
• Chicory root is one of the most effective prebiotic fibre sources in dog food

What does fibre actually do for dogs?

Fibre keeps your dog's digestive system working the way it should. It slows digestion enough to allow proper nutrient absorption, adds bulk to stools, and feeds the microbiome — the community of bacteria living in your dog's gut that influences almost every aspect of their health.

Without enough fibre, dogs are more prone to loose stools, constipation, anal gland problems, and blood sugar spikes. With the right amount, their digestion runs consistently, their gut bacteria stay balanced, and their immune system has a stronger foundation to work from.

It is one of the most overlooked nutrients in dog nutrition — not because it is complicated, but because it does its job quietly in the background.

What is the difference between soluble and insoluble fibre?

These two types of fibre work differently, and dogs need both.

Soluble fibre dissolves in water and is fermented — broken down and used as fuel — by the bacteria in your dog's gut. This is the type that feeds and sustains a healthy microbiome. Good sources include chicory root, oats, and chia seeds. Chia seeds in particular offer both soluble fibre and omega fatty acids in a single ingredient, which is why they appear in some better-quality fresh food recipes.

Insoluble fibre does not dissolve. It passes through the digestive tract largely intact, adding bulk to stools and helping food move through the gut at the right pace. Think of it as the physical scaffolding that keeps things regular. Common sources include vegetable matter and linseeds.

Too much insoluble fibre can actually speed digestion up too much, reducing how well nutrients are absorbed. Too much soluble fibre can cause gas and bloating. Balance is everything.

Which fibre sources are best in dog food?

Not all fibre sources are equal. Some are genuinely functional. Others are cheap fillers that add bulk to a recipe without doing much useful work.

Chicory root is one of the most researched prebiotic fibre sources for dogs. It contains inulin — a type of soluble fibre that selectively feeds beneficial bacteria like Lactobacillus and Bifidobacterium. The evidence for chicory root's impact on gut microbiome health in dogs is well established, and it is far more effective than generic fibre fillers found in lower-quality foods.

Linseeds (also called flaxseeds) are another solid option. They provide both soluble and insoluble fibre alongside omega-3 fatty acids, making them particularly useful for dogs with sensitive digestion or dry, dull coats. The benefits of linseeds extend well beyond fibre alone.

Marleybones includes chicory root in every recipe as a functional prebiotic, alongside chia seeds, linseeds, and hemp seeds — all of which contribute meaningful amounts of fibre rather than padding the recipe. The meals are vet-developed and FEDIAF compliant, so the nutritional balance has been properly considered rather than just ingredient-stacked.

Contrast this with many dry kibbles, where fibre often comes from beet pulp or rice hulls — cheap, low-value sources that tick a box without delivering the prebiotic benefit that genuinely supports the gut.

How does fibre affect common dog health issues?

Fibre has a direct impact on several conditions that owners deal with regularly.

Anal gland problems. This is one of the most common reasons vets recommend increasing fibre. Firm, well-formed stools naturally express the anal glands as a dog goes to the toilet. Loose or inconsistent stools do not, which leads to impaction and discomfort. Adequate insoluble fibre is the most straightforward dietary fix.

Loose stools and diarrhoea. Soluble fibre absorbs excess water in the gut and can help bulk up loose stools. It is one reason that a well-supported gut recovers faster from digestive upsets.

Weight management. Fibre slows gastric emptying — the rate at which food leaves the stomach — which helps dogs feel fuller for longer. For dogs prone to weight gain, a fibre-rich diet can reduce begging behaviour and calorie intake without reducing meal volume.

Blood sugar regulation. Soluble fibre slows the absorption of glucose into the bloodstream. This matters for diabetic dogs and is relevant for any dog prone to energy spikes and crashes after meals.

If your dog has persistent digestive problems that are not improving with dietary changes, speak to your vet. Chronic loose stools, significant weight loss, or blood in the stool warrant a proper clinical assessment rather than a diet adjustment alone.

For dogs who need extra gut support beyond food alone, a targeted prebiotic and probiotic supplement can work alongside a fibre-rich diet to help restore balance more quickly.

Every dog is different — build your personalised Marleybones feeding and health plan tailored to your dog's age, size, and health requirements.

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FAQs

How much fibre does a dog need per day?

There is no single universal figure, but most adult dogs do well with a diet containing 2–5% crude fibre by dry matter. Dogs with digestive issues, anal gland problems, or weight concerns may benefit from the higher end of that range. Check your dog's food label and look at the crude fibre percentage in the guaranteed analysis.

Can too much fibre harm a dog?

Yes. Excessive fibre — particularly insoluble fibre — can reduce the absorption of key nutrients including calcium, zinc, and iron. It can also cause loose stools, bloating, and excessive wind. More is not always better. The goal is balance between soluble and insoluble types, matched to your dog's size, age, and health.

What are signs that my dog is not getting enough fibre?

The most common signs are recurring anal gland problems, irregular stools (either very loose or very firm), and inconsistent digestion. Some dogs also show increased hunger between meals when their diet lacks enough fibre to slow digestion adequately.

Is chicory root safe for all dogs?

For most dogs, yes. Chicory root is well tolerated and widely used in quality dog foods as a prebiotic fibre source. In very large amounts it can cause loose stools, but at the levels used in properly formulated recipes it is safe and beneficial. Dogs with known gut conditions should have any significant dietary change discussed with a vet first.

Does Marleybones include fibre in its recipes?

Yes. Every Marleybones meal includes chicory root as a functional prebiotic fibre source, alongside chia seeds, linseeds, and hemp seeds. The recipes are vet-developed to ensure the fibre content supports gut health rather than simply bulking out the food.

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