Simultaneous diuresis cysto-urethrometry and multi-channel urethral pressure profilometry in female dogs with refractory urinary incontinence.

Objective: To assess urethral closure and bladder storage function in female dogs with refractory urinary incontinence by use of simultaneous diuresis cysto-urethrometry (UCM) and multi-channel urethral pressure profilometry (UPP).
Animals: 53 female dogs of various breeds with a history of 'non-neurogenic,' acquired urinary incontinence unresponsive to standard conservative treatment.
Procedure: UPP and UCM were performed on dogs sedated with xylazine, using a flexible polyvinylchloride multi-channel catheter connected to a perfusion system. Urine production was determined by use of radionucleotide dilution analysis. Values of reproducible urodynamic variables obtained previously in clinically normal dogs were compared with findings in the incontinent dogs. Cutoff values with the highest predictive values of urodynamic variables were determined and selected for functional classification.
Results: Except for threshold volume, median values of all urodynamic variables were significantly different between continent and incontinent dogs. Urethral pressure values, their relative variation, bladder threshold pressure, and prevalence of detrusor contractions were significantly lower than values in normal dogs, but compliance was higher. Forty-one dogs had urodynamic findings suggestive of poor urethral closure function assessed by UCM, but 10 of these had normal closure pressure values during UPP. Abnormal bladder storage function was interpreted from the findings of 19 dogs. Low capacity was found in 3, low threshold pressure in 15, and high compliance in 9 dogs. Seven of the dogs with abnormal bladder storage function had normal urethral closure function assessed by UPP and UCM. Five dogs had no abnormal findings, and 1 continent dog was abnormal by our classification.
Conclusions: Abnormal bladder storage function was suggested in a considerable number of dogs with refractory urinary incontinence.