A 9 mo old male Labrador retriever presented for investigation into persistent urinary incontinence. Abdominal ultrasound and retrograde urethrocystogram with computed tomography documented a uterus masculinus (UM), which was confirmed on histopathology after surgical removal. A connection between the UM and the urethra was present, documented by positive contrast retrograde urethrocystography and confirmed with surgery. Typically, in the literature, UM are blind ending, and there are only a few case reports that demonstrate an assumed connection. This case has demonstrated a patent connection between the UM and the urethra, which should be considered a differential diagnosis for persistent urinary incontinence and urinary tract infection in juvenile male dogs.