Abstract-based review · 2024
Cranberry feeding and a bacterial adhesion assay in cats
Reduced bacterial adherence was reported for some cats at 0.1% and all cats at 0.3%.
Review scope
Abstract-based review. Full methods, complete statistical results and product equivalence have not been appraised. This is research context, not an individual feeding or treatment recommendation.
Study question and design
Six neutered cats. Blinded crossover diets containing 0%, 0.1% or 0.3% cranberry powder, each for two weeks; urine used in a bacterial-cell adhesion assay.
Main findings
Reduced bacterial adherence was reported for some cats at 0.1% and all cats at 0.3%.
Limitations and applicability
An ex vivo assay does not demonstrate prevention or treatment of urinary infection in cats.
Ingredients investigated
Direct ingredient investigations
Cranberry
Direct · cat. Six neutered cats in a blinded dietary crossover experiment.
Tested form: Cranberry powder incorporated into the diet. Dose: 0.1% cranberry powder in the diet (Percentage of diet inclusion; dry-matter versus as-fed basis not established in the reviewed abstract). Duration: Two weeks for each dietary period. Comparator: Diet containing no cranberry powder.
Measured finding: Urine from the 0.1% cranberry period reduced bacterial adherence for 60% of the cats; urine from the 0.3% period reduced adherence for all cats in this assay.
Limitations: Six cats and short periods; ex vivo adhesion outcome rather than clinical infection. Cranberry extracts and other preparations were not established as equivalent to the powder.
Cranberry
Direct · cat. Six neutered cats in a blinded dietary crossover experiment.
Tested form: Cranberry powder incorporated into the diet. Dose: 0.3% cranberry powder in the diet (Percentage of diet inclusion; dry-matter versus as-fed basis not established in the reviewed abstract). Duration: Two weeks for each dietary period. Comparator: Diet containing no cranberry powder.
Measured finding: Urine from the 0.1% cranberry period reduced bacterial adherence for 60% of the cats; urine from the 0.3% period reduced adherence for all cats in this assay.
Limitations: Six cats and short periods; ex vivo adhesion outcome rather than clinical infection. Cranberry extracts and other preparations were not established as equivalent to the powder.
Evidence.pet interpretation
Apply this result only within its species, preparation and study conditions. An ingredient listing alone does not establish that a commercial product reproduces the tested intervention.
Funding and conflicts
Authors included pet-food research and development affiliations. Full funding and conflict declarations were not appraised.
Ingredient references
These are research references. The tested form, dose and formulation must be matched before using a result to support a product claim.
Source
Carvajal-Campos A et al. The effect of consumption of cranberry (Vaccinium macrocarpon) on Escherichia coli adherence to feline uroepithelial cells in a blind randomised cross-over trial in cats. Journal of Veterinary Research. 2024. DOI: 10.2478/jvetres-2024-0055.
Primary source record (PMID 39776678) · Publisher DOI
Reviewed 2 October 2026 · Next review 2 January 2027.