Relationship between ultrasonographic appearance, testicular size, spermatozoal output and testicular lesions in the dog

The ultrasonographic appearance of the dog testis and epididymis was examined in vivo and in vitro. The relationship between specific testicular and epididymal dimensions was studied in normal animals. Assessment of testicular volume using ultrasound compared favourably to the volume calculated by water displacement. The correlation between testicular volume, epididymal cross-sectional area and semen parameters was, however, poor. Changes in the normal testicular architecture were identified in a variety of pathological conditions including testicular cysts and neoplasia.