Diagnostic Imaging of the Prostate in Small Animals

Prostatic disorders are extremely common in intact male dogs. They are much less commonly encountered in cats and in castrated animals, especially those that have been neutered at a young age. An aetiological diagnosis can rarely be made on the basis of clinical signs alone.^1,2 Diagnostic imaging is of major value to confirm prostatic abnormalities, however interpretation requires caution, as imaging features are rarely disease-specific. One major difficulty in diagnosing prostatic abnormalities is the wide variation in prostatic size and appearance, due to the normal occurrence of BPH in intact male dogs.

The two most common disorders in small animals are benign prostatic hyperplasia (BPH) and prostatitis.³ Neoplasia is rare in carnivores but difficult to diagnose and even more difficult to treat. Adenocarcinoma is most common but transitional cell carcinoma invasion may occasionally occur, non-epithelial tumours being less frequent.^4-7 Although standard radiography is still commonly used as a first line imaging technique, a combination of clinical examination and ultrasonography is usually considered the gold standard to assess the prostate.²

Advanced imaging methods such as contrast-enhanced ultrasonography, scintigraphy, computed tomography (CT) and magnetic resonance imaging (MRI) can be helpful to look for signs of neoplasia and for tumour staging^2,8-11, however biopsy or cytological examination of fine-needle-aspirates (FNA) are often necessary for a definitive diagnosis. [...]