Use of Computed Tomography, Ultrasound, and Vaginoscopy in the Evaluation of a Bilobed Vaginal Müllerian Cyst in a Neutered Female Labrador Retriever.

An 11-year-old neutered female Labrador was presented with dyschezia and dysuria associated with a large perineal mass that had been present for 2 years. Computed tomography (CT) revealed a large bilobed, cavitated mass localized ventrally to the rectum and dorsally to the urethra at the level of the vagina, with hypoattenuating contents and a contrast-enhancing peripheral wall. Surgical excision was performed and confirmed the cystic nature of the mass. Histopathological findings were compatible with a benign vaginal cyst, most likely originating from the Müllerian or paramesonephric ducts. The CT provided relevant information for surgical planning and enabled accurate assessment of the mass's location, extent, and relationship with adjacent structures.