Four-dimensional CT excretory urography imaging findings, cystoscopy and exploratory surgery for the diagnosis of a vesicovaginal fistula in a young dog

An eight-month-old, entire female German Shepherd was referred for investigation of continuous urinary incontinence not responding to medical therapy. A four-dimensional excretory urography (4D-CTEU) abdominal CT scan revealed a hypoattenuating fluid-filled structure dorsally to the urinary bladder, extending cranially, continuing as the uterine horns, and ending blindly caudally. On post-contrast images, during all contrast phases, a continuity of the urinary bladder and cranial vaginal walls was underlined by a hyperattenuating mucosal surface with the creation of a hypoattenuating fistulous tract. Cystoscopy and exploratory surgery confirmed the presence of a vesicovaginal fistula and revealed that the distal vagina and urethra consisted of one structure.