COMPARISON OF URETHRAL PRESSURE PROFILOMETRY AND CONTRAST RADIOGRAPHYIN THE DIAGNOSIS OF INCOMPETENCE OF THE URETHRAL SPHINCTER MECHANISM IN BITCHES

Three diagnostic indicators of urethral sphincter mechanism incompeten ce were compared in 25 continent and 25 incontinent anaesthetised bitc hes: the resting urethral pressure profile, the stressed urethral pres sure profile and the radiographic position of the bladder neck. Logist ic regression indicated that the best predictor of continence status w as the stressed urethral pressure profile as assessed by the percentag e of negative peaks extending below the resting intravesical pressure; it classified 43 of the 50 dogs correctly. The radiographic position of the bladder neck was a better predictor of continence than either t he measurement of functional profile length or the maximum urethral cl osure pressure from the resting urethral pressure profile, whether alo ne or in combination. By combining the percentage of negative peaks on the stressed profile with the position of the bladder neck, 46 of the 50 dogs were classified correctly. Cut-off values for the percentage of negative peaks on the stressed urethral pressure profile, and for t he radiographic position of the bladder neck are suggested for use in evaluating incontinent bitches in clinical practice.