Novel catheter design enables transurethral catheterization of male mice

The male mouse is underrepresented in research of the urinary tract due to the difficulty of transurethral catheterization. As a result, there is a lack of analysis of sex differences in urinary tract research. Here, we present a novel catheter design and technique that enables urethral catheterization of male mice for bladder inoculation. Our catheterization technique uses the resistance met at the level of the external urinary sphincter and prostate to guide the retraction, positioning, and advancement of the catheter into the urinary bladder. We have shown that this method can be used to reproducibly catheterize 12 male mice with minimal urogenital trauma but cannot be used as a cystometric technique. This method will facilitate the expansion of research into sex differences in various genitourinary conditions that require transurethral catheterization of mice.