Incomplete urethral duplication with cyst formation in a dog.

Incomplete urethral duplication with cyst formation was diagnosed in a dog that had soft, fluctuant, subcutaneous swellings in the ventral perineal and penile areas and a history of nocturia and incontinence during recumbency that were unresponsive to treatment with antibiotics. Retrograde urethrocystography, voiding urethrography, double-contrast cystography, radiography after direct administration of contrast medium into cystic structures, and excretory urography were performed to evaluate the urinary tract. Communication between the cysts and the urethra was demonstrated radiographically only after intralesional injection of contrast medium. Nocturia and incontinence resolved after surgical removal of the urethral duplication and cysts. The dog was clinically normal 1 year after surgery.