Ultrasonographic evaluation of induced testicular lesions in male goats.

To study testicular ultrasonographic features, unilateral testicular artery ligation was performed in 12 bucks to induce predictable ischemic necrosis of the testis. Both scrotal testes then were scanned subsequently on days 1, 3, 5, 7, 15, and 30. On each of the designated days, 2 bucks each were castrated and the excised testes were rescanned outside the scrotum before gross and histologic examinations. In each goat, the testis without the ligated artery served as a control. Gross and histopathologic findings in the testis were compared with ultrasonographic observations. As the study progressed from day 0 to day 15, visually and microscopically, the testis involved in the testicular artery ligation had edema that changed to areas of peripheral necrosis with thickening of the testicular capsule. On day 30, the affected testis had granulation tissue in the areas that previously had been necrotic. Ultrasonographically, the testicular changes were consistent with the gross and histopathologic findings. There were areas of decreased echogenicity that corresponded to the necrotic areas and foci of high echogenicity that corresponded to areas of tubular mineralization. On day 30, the granulation tissue was difficult to differentiate ultrasonographically from normal testicular parenchyma. Between days 3 and 15, hydrocele was seen ultrasonographically in several goats. The excellent association between ultrasonographic findings and gross and histologic changes suggested that testicular ultrasonography might be a valuable diagnostic tool for assessing testicular disease in domestic animals.