Feline urethral obstruction alters the urinary microbiota and comparison to oral, preputial, and rectal microbiotas.

Objective: To document differences in the microbiota of healthy cats versus cats with urethral obstruction (UO); compare the urinary microbiota with the oral, preputial, and rectal microbiota; and demonstrate that 16S rRNA gene sequencing will reveal rich and diverse urinary microbiota.

Methods: 15 client-owned cats with UO and 15 age-matched healthy cats were included from July 2020 through April 2021. Exclusion criteria were evidence of urinary tract infection, urolithiasis, antimicrobial administration, urinary catheterization in the past 30 days, or a comorbidity. This study was a prospective, observational study. Both groups had a baseline CBC, chemistry panel, urinalysis, urine culture, and focal bladder ultrasound. Swabs of the cystocentesis site, buccal mucosa, rectum, prepuce, and urinary samples were collected, and 16S rRNA gene sequencing was used to compare the groups and sites.

Results: Differences in the microbiota richness and diversity were found in the urine of cats with UO (n = 15) compared to healthy cats (15), along with differences in the preputial and oral samples, supporting the presence of a urinary dysbiosis in cats with UO.

Conclusions: Our preliminary data demonstrates a dramatic change in the urinary microbiota of cats with UO along with changes in microbiota in other sites compared to healthy cats.

Clinical Relevance: A urinary dysbiosis in cats with UO has been minimally supported in prior studies using 16S rRNA gene sequencing. Although these are preliminary results, documenting this dysbiosis in cats with UO provides a potential avenue for novel therapeutics.