Objective: To study a combined urodynamic technique for assessment of urethral closure and bladder storage function in female dogs.
Animals: 20 healthy, adult, sexually intact female dogs of various breeds.
Procedure: Urethral pressure profilometry and continuous urethral pressure registration during high-diuresis cystometry (cysto-urethrometry) were studied in dogs sedated with xylazine. Pressures were measured, using a flexible polyvinylchloride multichannel catheter connected to a perfusion system. Urine production and volume were determined by radionucleotide dilution analysis of urine samples. Urethral pressure profilometry was performed first, followed by cystourethrometry. Maximal urethral pressure and maximal urethral closure pressure of consecutive profiles and their mean values were determined. Closure pressure at its highest and lowest level and at micturition threshold and absolute and relative magnitude of urethral pressure variation were determined in the high-pressure zone of the urethra while the bladder filled, enforced by diuresis. Bladder pressure and volume at the micturition threshold and static compliance also were determined.
Results: Differences in mean and variance between variables listed were not significant. Urethral closure pressure varied from 5 to 67 cm of H2O during bladder storage. So-called unstable detrusor contractions were observed in 6 dogs.
Conclusions: Several variables for the assessment of the dynamics of urethral closure and bladder storage function obtained by the technique reported here are reproducible. Values from this study are considered reference values for further studies.
Clinical relevance: The reported technique can be helpful in the investigation of complicated urinary incontinence in female dogs.