Psyllium versus cellulose in healthy cats

Direct · cat. Nine healthy neutered adult cats.

Tested form: Food containing approximately 6% psyllium husk powder. Dose: Approximately 6% (Percentage of food). Duration: 10 days. Comparator: Approximately 6% cellulose food, always fed second after a four-day washout.

Measured finding: Mean daily bowel movements were 1.6 versus 1.1; mean stool scores were 3.2 versus 2.6. Median moisture was 72.9% versus 66.5%.

Limitations: Small sample, fixed treatment order, and short collection periods. Psyllium stools were softer than the study’s optimal score; constipation relief was not measured.

Abstract reviewed · Checked 25 September 2026 · Evidence.pet study summary · Primary source

Psyllium-containing diets for chronic constipation in cats

Multi ingredient · cat. Cats with chronic constipation; 49 enrolled and two excluded. Diet-switch analyses included 26 test and 30 control diet observations, not 56 independent cats.

Tested form: Psyllium husk incorporated into a complete gastrointestinal diet. Dose: 0.5% psyllium as fed (Percentage of the complete diet as fed; oral feeding). Duration: 6 months. Comparator: Complete gastrointestinal test diet containing 6% psyllium as fed.

Measured finding: Failure was reported for 26.9% of test-diet observations versus 73.3% of control-diet observations. Clinical signs improved with both diets.

Limitations: Whole-diet comparison and diet-switch observations; sample counts across analyses must not be added as unique cats. Authors included Royal Canin employees. Product inclusion level and formulation need separate verification.

This ingredient was part of a combined formulation; the study does not isolate its contribution.

Abstract reviewed · Checked 2 October 2026 · Evidence.pet study summary · Primary source

Psyllium-containing diets for chronic constipation in cats

Multi ingredient · cat. Cats with chronic constipation; 49 enrolled and two excluded. Diet-switch analyses included 26 test and 30 control diet observations, not 56 independent cats.

Tested form: Psyllium husk incorporated into a complete gastrointestinal diet. Dose: 6% psyllium as fed (Percentage of the complete diet as fed; oral feeding). Duration: 6 months. Comparator: Complete gastrointestinal control diet containing 0.5% psyllium as fed.

Measured finding: Failure was reported for 26.9% of test-diet observations versus 73.3% of control-diet observations. Clinical signs improved with both diets.

Limitations: Whole-diet comparison and diet-switch observations; sample counts across analyses must not be added as unique cats. Authors included Royal Canin employees. Product inclusion level and formulation need separate verification.

This ingredient was part of a combined formulation; the study does not isolate its contribution.

Abstract reviewed · Checked 2 October 2026 · Evidence.pet study summary · Primary source

Resistant starch, psyllium and methylcellulose: a dog microbiome comparison

Direct · dog. 17 healthy dogs transitioned to the same complete food.

Tested form: Psyllium husk supplement; dose and detailed preparation not reported in the reviewed abstract. Dose: Not reported in the reviewed abstract (Supplement amount and feeding basis not reported). Duration: Not reported in the reviewed abstract. Comparator: Measurements before and after each supplement, with washouts.

Measured finding: Psyllium had minor taxonomic effects in this small study; the abstract does not establish a clinical benefit.

Limitations: Small healthy population. Sequencing results cannot establish clinical benefit or harm; findings concern the tested fibre preparations.

Abstract reviewed · Checked 25 September 2026 · Evidence.pet study summary · Primary source

Treatment of chronic idiopathic large-bowel diarrhea in dogs with a highly digestible diet and soluble fiber: a retrospective review of 37 cases

Multi ingredient · dog. Dogs with chronic idiopathic large-bowel diarrhoea; 37 retrospective cases.

Tested form: Psyllium-containing Metamucil combined with a highly digestible diet. Dose: Not reported in the existing abstract (Oral feeding; amount not reported). Duration: Not reported in the existing abstract. Comparator: No randomised control.

Measured finding: Most dogs improved on the combined diet and fibre regimen.

Limitations: Retrospective uncontrolled combined treatment; cannot isolate psyllium effect. Not a Tuggs product study.

This ingredient was part of a combined formulation; the study does not isolate its contribution.

Abstract reviewed · Checked 25 September 2026 · Evidence.pet study summary · Primary source