Back to the knowledge base

Fibre in dog and cat diets

A short guide to the role of Fibre in dog and cat nutrition.

Fibre

Fibre is the fraction of carbohydrates that a dog's or cat's body cannot digest with its own enzymes. It is not an "essential" nutrient in the nutritional sense — there is no established minimum requirement in the NRC standards [1]. Even so, in reasonable amounts it serves useful functions in the gut. Two different types hide under a single name (see also Carbohydrates):

  • Soluble fibre (pectins, inulin, beta-glucans) — not fermented by the animal, but fermented by large-intestine bacteria into short-chain fatty acids (SCFA: butyrate, propionate, acetate), which nourish gut cells, support the gut barrier and have anti-inflammatory effects [2]. Sources: pumpkin, peeled apple, psyllium.
  • Insoluble fibre (cellulose, hemicellulose, lignin) — not fermented, mechanically increases faecal bulk and regulates transit. Sources: leafy vegetables, peels, stalks. In the cat this role is filled in nature by the bones, cartilage and fur of prey.

Where it's found: Exclusively in plant raw materials. In BARF most often from vegetables and fruit or from a deliberate addition (pumpkin, psyllium). A dog does not digest cellulose — raw, unblended vegetables pass through almost undigested, so it's worth blending or lightly cooking them. A cat needs the least plant fibre and it should not be a permanent element of its diet.

Deficiency: It does not occur as a clinical entity — there is no "fibre deficiency" in a dog or cat [1]. A meat-bone-offal diet without added fibre is correct. In practice, in some animals a very low-residue diet is sometimes associated with harder stools or (in cats) hairballs — then a small, deliberate addition of soluble fibre can help.

Excess: Too high a fibre share dilutes the nutritional value of the diet, can cause loose stools, flatulence and greater faecal volume, and can also reduce the absorption of some minerals [2]. A high fibre share (especially from legumes) is sometimes linked to a worse taurine balance in dogs — the mechanism is not fully clear [3]. That's why you should treat fibre as a tool, not as an ingredient to "sprinkle in for health".

When fibre can be useful

A small addition of soluble fibre (pumpkin, psyllium) helps with constipation and loose stools, in cats with hairballs, and in dogs with a sensitive gut or IBD it can be supportive. In animals with diabetes it slows glucose absorption, and in obese ones low-starch vegetables increase meal volume at low caloric value. These are deliberate, individual uses — not a dietary standard.

Sources

  1. National Research Council (NRC) (2006). Nutrient Requirements of Dogs and Cats — no established minimum requirement for fibre. National Academies Press. https://nap.nationalacademies.org/catalog/10668/nutrient-requirements-of-dogs-and-cats
  2. Hand MS, Thatcher CD, Remillard RL, Roudebush P, Novotny BJ (2010). Small Animal Clinical Nutrition, 5th Edition. https://www.markmorrisinstitute.org/sacn5.html
  3. McCauley SR, Clark SD, Quest BW, Streeter RM, Oxford EM (2020). Review of canine dilated cardiomyopathy in the wake of diet-associated concerns. J Anim Sci 98(6):skaa155. https://doi.org/10.1093/jas/skaa155