Computed Tomographic and Ultrasonographic Characteristics of Presumed Traumatic Unilateral Cavernositis of the Penis in a 2-Year-Old Dog.

A 2-year-old male entire Samoyed presented with 2 weeks of suspected lumbar pain, following an episode of compulsive hypersexual behavior towards other dogs. Computed tomography revealed a lobulated, enlarged left corpus cavernosum with a central non-enhancing, hypoattenuating region (-20 to 40 HU) and rim enhancement, surrounding ischiocavernosus muscle swelling, and left-sided bulbus penis hyperenhancement. Ultrasound showed an enlarged heterogeneous hyperechoic left corpus cavernosum. Ultrasound-guided needle aspiration for cytology, interpreted by a board-certified clinical pathologist, revealed mesenchymal proliferation and mild macrophagic inflammation, supporting a diagnosis of cavernositis. The dog was treated with anti-inflammatories and antibiotics with clinical resolution at a 4-week follow-up.