VGO 511: Veterinary Andrology and Reproductive Techniques (1+1)

TESTICULAR DEGENERATION

• Testicular degeneration may be mild or severe and is usually bilateral as it is most commonly due to generalized disease processes.

• Unilateral degeneration can occur secondary to local testicular lesions such as tumors.

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Testicular degeneration may develop very rapidly within a few days or hours; while testicular regeneration proceeds slowly over weeks and months.

• If the basal layers of the germinal epithelium including the spermatogonia and sertoli cells are destroyed regeneration of the germinal epithelium is not possible and the animals is sterile.
• The pattern and signs of testicular degeneration are about the same despite the species or the etiologic factors involved.
• In all cases, degenerative changes noticed in the mechanism of cell division or centrosomes in the primary spermatocytes are responsible for reduced motility and increased numbers of pathologic spermatozoa with an abnormal morphology.
• Sperm cell numbers and concentration are decreased depending on the degree of degeneration of the seminiferous tubules.
• In severe disturbances of spermatogenesis, spermatocytes with restitution nuclei with double the normal number of chromosomes as well as pyknotic nuclei are present in the ejaculate.
• Testes with degeneration of the seminiferous tubules are usually atrophic and softer and smaller than normal testes.
• In chronic cases the testicle may be firm due to fibrosis even calcium may be deposited especially in the areas just peripheral to the rete testis.
• Histologically it may be difficult to distinguish between slight degrees of testicular degeneration and hypoplasia.

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