Healthy digestion is one of the best signs of a healthy dog. And when it comes to stool quality, fibre plays a starring role. The right balance and type of dietary fibre can help firm up loose stools, prevent constipation, and support a balanced gut microbiome.
You can also consider using probiotics in combination with fibre to improve your dog's gut health if your dog has stool issues. You can read more about probiotics in our article 🐾 Probiotics for Dogs: How They Support Gut Health & Better Stool Quality
💡 Why Fibre Matters
Fibre (non-digestible carbohydrates) is the part of plant material that passes through your dog’s digestive tract mostly unchanged. Even though it doesn’t provide energy directly, it plays several vital roles in maintaining digestive health:
Supports normal bowel movements
Regulates stool consistency
Feeds beneficial gut bacteria (prebiotic effect)
Contributes to a feeling of satiety in overweight dogs
🧬 Types of Fibre Explained
Type | Description | Common Sources | How It Affects Stool |
Soluble fiber | Dissolves in water and forms a gel-like substance. Found in fruits, vegetables, and certain grains. | Psyllium husk, beet pulp, pumpkin, oats, apples (without seeds), carrots, sweet potato, green beans, flaxseed, chia seeds. | Helps slow digestion and firm up loose stool by absorbing excess water. |
Insoluble fiber | Does not dissolve in water. Adds bulk and promotes intestinal movement. | Broccoli stalks, spinach stems, kale, cabbage, celery, wheat bran, brown rice, whole grains, root vegetable peels. | Adds bulk and helps stimulate movement in the intestines, reducing constipation. |
👉 A healthy diet for most dogs includes a mix of soluble and insoluble fibres for balanced stool consistency and gut health.
🥦 Practical Examples of Fibre Sources
Food | Fiber Type | Benefits | Preparation Tip |
Pumpkin (cooked) | Soluble | Firms up stool; gentle on stomach | Use 1 tsp–2 tbsp, depending on dog size |
Psyllium husk | Soluble (mostly) | Absorbs excess moisture and softens stool | Mix with water or wet food (½–2 tsp daily) |
Beet pulp | Soluble | Supports beneficial gut bacteria | Common in quality kibble; not raw beet! |
Carrots (cooked or raw grated) | Mix | Adds mild bulk, good for dental health | Offer as a crunchy snack or grated in food |
Green beans (cooked) | Mix | Low-calorie filler; aids stool formation | Chop and steam lightly |
Broccoli (cooked, in small amounts) | Insoluble | Adds bulk, helps move stool | Avoid excess (can cause gas) |
Sweet potato (boiled/mashed) | Soluble | Adds moisture-binding fibre; vitamin-rich | Start with 1 tbsp for medium dogs |
Flaxseed or chia seeds (ground) | Mix | Prebiotic and omega-3 benefits | Sprinkle a small amount on the food |
Wheat bran/oat bran | Insoluble | Increases stool volume and motility | Add sparingly; too much can cause diarrhoea |
⚠️ Always introduce fibre gradually over 3–5 days to avoid bloating or gas.
🌿 Psyllium Husk — The All-Round Stool Stabiliser
Psyllium husk is a unique and powerful dual-action fiber that helps normalize stool whether it’s too loose or too hard.
Made up to 80% soluble fibre, it forms a gel-like texture when mixed with water — helping balance stool consistency in both directions.
Situation | How Psyllium Works | Effect |
Loose stool or diarrhoea | Absorbs excess water in the intestine | Firms up stool and slows transit time |
Constipation or dry stool | Retains moisture in the stool | Softens stool and stimulates bowel movement |
Suggested daily amounts:
Dog Size | Daily Amount | Instructions |
Small (≤10 kg) | ½ teaspoon | Mix with water or moist food |
Medium (10–25 kg) | 1 teaspoon | Divide across meals if possible |
Large (≥25 kg) | 1½–2 teaspoons | Always ensure hydration |
💧 Important: Psyllium expands 10–15× in size when hydrated. Always serve it with sufficient water or wet food to avoid constipation.
🩺 Use short-term for stool regulation or under vet guidance for longer periods.
🥩 Raw Feeding and Constipation
Raw feeding (also known as BARF – Biologically Appropriate Raw Food) can be excellent for many dogs, but it often lacks one crucial component — dietary fibre.
Because raw diets are typically high in protein and fat but low in plant matter, they may lead to:
Dry, hard, or infrequent stools
Straining during defecation
Reduced stool volume but potential constipation risk
💡 Why It Happens
Meat, bone, and organ components are almost fully digested — leaving very little residue for stool bulk. Without enough indigestible material (fibre), the intestines have less to “push” through, which slows motility.
✅ What Helps
Add vegetable purées: pumpkin, spinach, carrots, zucchini, or green beans (lightly cooked and blended).
Introduce psyllium husk or beet pulp in small doses to improve moisture retention and stool movement.
Ensure adequate hydration — many raw-fed dogs don’t drink as much since their food already contains moisture.
Maintain about 2–5% fibre content in the overall diet for healthy bowel function.
⚠️ Watch for chalky, white stool — this may indicate too much bone and too little fibre in the raw mix.
🍪 Dry Kibble and Loose or Bulky Stool
Dogs eating commercial dry kibble often have the opposite problem — large stool volume or soft stool.
💡 Why It Happens
Kibble diets tend to:
Contain high amounts of carbohydrates and plant by-products for structure.
Include fermentable fibers and fillers (e.g., soy hulls, pea fiber, beet pulp, legumes).
It has low moisture (≈10%), which can dehydrate the stool.
In cheaper brands, use low-quality ingredients that ferment excessively, causing gas and loose stools.
This can lead to:
Bulky, smelly stool due to undigested matter.
Soft or loose stool occurs when fibres ferment too quickly or bind water inefficiently.
Inconsistent stool quality when ingredient batches vary.
✅ What Helps
Choose high-quality kibble with moderate fibre (2–4%) and named ingredients (avoid “by-product meal”).
Mix in a spoon of cooked pumpkin or psyllium husk to improve stool form.
Ensure the dog drinks enough water to balance the dryness of kibble.
Avoid overfeeding — excess food increases fermentation and stool size.
💡 Tip: If your dog’s stool volume is large or soft on kibble, it’s often a sign the diet isn’t being efficiently digested.
🧫 Fibre and Gut Health
Fibre also acts as a prebiotic, meaning it feeds beneficial bacteria like Lactobacillus and Bifidobacterium in your dog’s gut.
This supports:
A more balanced microbiome
Better immune regulation
Reduced inflammation and gas
Some specialised fibre sources like FOS (Fructo-oligosaccharides) and MOS (Mannan-oligosaccharides) are often added to high-quality pet foods for this reason.
⚖️ Finding the Right Fibre Balance
Too much or too little fibre can both cause problems.
Problem | Possible Fibre Cause | Adjustment Tip |
Loose stool | Too little soluble fibre | Add small amounts of psyllium or pumpkin |
Constipation | Too little insoluble fibre | Add broccoli, green beans, or bran |
Large stool volume | Too much total fibre | Reduce fibre slightly |
Gas or bloating | Excess fermentable fibre | Switch to less fermentable sources like beet pulp |
🧩 Integrate Fibre Tracking With Furry Fitness
When you use the Stool Tracker in the Furry Fitness app, you can log stool consistency (based on the Bristol Stool Scale for dogs) and note any dietary adjustments — like adding fibre.
Over time, this helps you see how diet changes affect your dog’s gut health.
👉 If you haven’t already, read our related article:
“Stool – The Window to Your Dog’s Gut Health”
💬 Tip: Track stool consistency daily in your app to see how changes affect your dog’s digestion.
🧠 Key Takeaway
A balanced amount of soluble and insoluble fiber — especially functional fibers like psyllium husk — supports healthy stool quality and gut function.
Start slowly, monitor stool consistency in your app, and adjust the amount as needed.
Always consult your vet before making major diet changes.
🔬 Science References
Barry, K. A. et al. (2010). Dietary fiber and canine gastrointestinal health. Journal of Animal Science, 88(11), 3966–3975.
Bosch, G. et al. (2009). The importance of fermentable fibers in canine diets. British Journal of Nutrition, 102(S1), S21–S23.
Swanson, K. S. et al. (2002). Influence of fiber source on gastrointestinal health in dogs. American Journal of Veterinary Research, 63(12), 1697–1706.
FEDIAF Nutritional Guidelines (2023). Balanced dietary fiber inclusion in dog foods.