Pathophysiology, diagnosis, and management of testicular degeneration in the bull

Testicular degeneration in the bull is described as diffuse disintegration of seminiferous tubule structure and function causing a profound reduction in sperm concentration, scrotal circumference, and an increase in sperm morphologic abnormalities resulting in subfertility or permanent infertility. Degenerative changes within the seminiferous epithelium occur most commonly after an insult to spermatogenesis or may be idiopathic. Common insults include trauma, stress (environmental, heat, nutritional), or toxins. Idiopathic is most often associated with age-related changes. Clinical signs of testicular degeneration are discussed along with approaches to treatment and potential prognoses as related to treatment and management practices that can be employed by the general practitioner and specialist alike. This review will also encompass a discussion on the pathophysiology of this disease so that the practitioner has a detailed understanding of the disease, which improves their ability to employ evidence-based medicine and sound clinical reasoning.