Vaginal position and length in the bitch: relationship to spaying and urinary incontinence

A study was undertaken to determine if the vagina might be a suitable site for the measurement of intra-abdominal pressure during cystometry in the bi tch, The position of the cranial vagina and vaginal length were measured ra diographically and the effects of spaying and urinary Incontinence on these variables were evaluated in 30 continent and 30 incontinent bitches. The s tudy used retrograde vaginourethrograms which had been obtained from animal s used in a previous study, The cranial vagina was intra-abdominal on 36 of the vaginourethrograms, being least commonly intra-abdominal in incontinen t bitches (11/30), Vaginal position was related linearly to vaginal length and continence status (P<0.01), while its length was related to bodyweight( P<0.01). Allowing for bodyweight, neutered animals had significantly shorte r vaginas than entire bitches (P<0.01). Measurement of intra-abdominal pres sure with concomitant measurement of intravesical pressure is essential if accurate assessment of detrusor pressure is to be determined during cystome try, The vagina is unlikely to be a useful location from which to measure i ntra-abdominal pressure since any pressure-measuring catheter inserted into it may fall outside the abdominal pressure zone. This is particularly true of neutered and/or incontinent bitches, the groups in which urodynamic inv estigations of urinary incontinence are most frequently indicated.