Review scope

The full paper was reviewed for this summary.

Question and design

Nine healthy neutered adult cats. A food containing approximately 6% psyllium for ten days. Comparator: Approximately 6% cellulose, always fed second, after a four-day washout.

What was measured?

Bowel movements, stool consistency, moisture and wet weight.

Main findings

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%.

Study strengths

Within-cat comparison and measured moisture alongside visual scoring.

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.

Researchers’ conclusion

The authors supported further evaluation for constipation management.

Evidence.pet interpretation

Stool softening may be relevant to constipation, but softer is not automatically healthier in an already healthy cat.

Funding and conflicts

Royal Canin/Mars Petcare funded the work; five authors disclosed company employment.

Source and review date

Keller E et al. Psyllium husk powder increases defecation frequency and faecal score, bulk and moisture in healthy cats. Journal of Feline Medicine and Surgery. 2024;26(4):1098612X241234151.

Read the primary source · DOI record

STU-038. Reviewed 25 September 2026. Next review 25 December 2026.