“…The mediastinum appears in the longitudinal plane as a hyperechoic central line and in the transverse plane, appears as an echogenic spot ( Figure 1). In prepubescent dogs, the echogenicity of the testis is more hypoechoic than in adult dogs and the mediastinum can be easily identified (Souza et al, 2017). In older dogs, small hyperechoic foci representing the testicular septa are occasionally visualized (Penninck and D'anjou, 2015).…”