FIC is typically considered non-infectious, yet interest in the “urobiome” has grown as clinicians look for factors that might influence bladder inflammation and recurrence. This paper adds to the emerging evidence that urine may contain detectable bacterial DNA — and that community patterns may differ in cats diagnosed with FIC — but it also highlights how hard it is to separate true biology from methodological noise in low-biomass samples.
The Study
This prospective study (client-owned cats at a Thai veterinary teaching hospital, 2021–2022) collected urine by cystocentesis under aseptic prep, excluded cats with positive aerobic culture and those given antibiotics or probiotics within 30 days, and profiled urinary bacterial DNA using 16S rRNA (V3–V4) sequencing with positive and negative lab controls.
Key results:
- Baseline profile: In healthy cats, urinary microbiota profiles were dominated by Proteobacteria, with Pseudomonas a prominent genus.
- Age/sex differences: No significant differences were detected between males and females; some taxa varied by age, with young cats showing higher within-sample diversity
- Phylum shifts: Compared with healthy cats, cats with FIC showed lower Proteobacteria and higher Firmicutes
- Genus changes: Pseudomonas was markedly lower in FIC cats (45.3% in healthy vs 2.9% in FIC), and Corynebacterium was also reduced in FIC.
Key takeaways for practice
- This study supports the idea that urine is not always “sterile” at the DNA level, and that cats with FIC may show altered urinary microbial community patterns compared with healthy controls — but it does not show that bacteria are causing FIC.
- For now, the findings do not change first-line FIC principles - but further research in this area might provide new avenues for treatment in the future!
Source: Scientific Reports, “Characterization and comparative analysis of urinary bacterial microbiome profiling in healthy cats and cats with feline idiopathic cystitis”.