Review scope

This summary is based on the published abstract. We have not appraised the full methods, tables or supplementary material. Details absent from the abstract remain unverified.

Question and design

Six healthy adult cats in a randomised crossover; three weeks per food. The same complete dry food hydrated to approximately 25%, 53% and 73% moisture. Comparator: The original food at 6.3% moisture.

What was measured?

Fluid intake, urine volume, specific gravity and calculated crystal supersaturation.

Main findings

At 73.3% moisture, urine was more dilute and calcium-oxalate relative supersaturation was lower than with dry food. Struvite differences were not significant.

Study strengths

The nutritional composition was held constant while moisture changed.

Limitations

Small healthy sample. Calculated supersaturation is a risk marker, not observed stone incidence or recurrence.

Researchers’ conclusion

The authors linked the highest moisture level with improved urine dilution and a lower calcium-oxalate risk marker.

Evidence.pet interpretation

This informs moisture research but does not show that all wet foods prevent urinary stones.

Funding and conflicts

Not verified from the abstract; full declarations have not been reviewed.

Source and review date

Buckley CMF et al. Dietary water intake, urine dilution and crystal relative supersaturation in cats. British Journal of Nutrition. 2011. Title shortened; PMID 22005408 identifies the paper.

Read the primary source

STU-037. Reviewed 25 September 2026. Next review 25 December 2026.