Pathogenesis, Diagnosis, and Management of Testicular Degeneration in Stallions

Testicular degeneration is a common cause of subfertility and infertility in stallions. The disease can broadly be divided into two categories: those cases resulting from a known testicular insult, and idiopathic (senile or age-related) testicular degeneration. This manuscript describes the problem of testicular degeneration in the equine breeding industry and summarizes what is known about the pathophysiology of the disease. Additionally, the clinical signs of testicular degeneration are reviewed so that the clinician can more quickly and accurately arrive at a diagnosis. Differences in the approach to treatment of testicular degeneration arising from a known cause and idiopathic testicular degeneration are discussed as are differences in prognoses. Finally, the practitioner is provided with practical information on how to more effectively manage affected stallions and what, if anything, can be done to improve reproductive performance of these animals both in the field and in a referral setting.