The Visual Guide to
Equine Reproduction
Male Reproductive System: Testis and Epididymis
Testicular Volume.
Special calipers are used to measure testicular diameter. Testicular volume is correlated with the quantity of sperm production. Scrotal width should be at least 8 cm, as one of the criteria in determining the final classification of the breeding soundness of the stallion.
Asbury AC (1988)
Cystic Periorchitis.
Chronic cystic periorchitis. Thickened tunics.
Shipley C (2006)
Thickened Tunics.
Close-up of thickened tunics in a case of chronic cystic periorchitis.
Shipley C (2006)
Chronic Cystic Periorchitis.
Thickened tunica albuginea and tunica vaginale and chronic orchitis.
Shipley C (2006)
Thickened Tunics - Close-up.
Thickened tunics surrounding a chronically inflamed testicle.
Shipley C (2006)
Thickened Tunics.
Thickened tunica albuginea and tunica vaginalis around a chronically inflamed testis.
Shipley C (2006)
Appendix Testis.
The appendix testis is a paramesonephric duct cyst which is a remnant of the female mesonephric duct system.
Roberts SJ (1972)
Retained Testis.
Testes from a 3-year old stallion. The retained testis weighed 32 grams and the normal descended testis 244 grams.
Roberts SJ (1972)
Testicular Torsion.
Testes of a stallion following bilateral castration. The testis on the left is normal; the testis on the right suffered from testicular torsion. Congested blood vessels can be seen in the afflicted spermatic cord and the testicle is slightly smaller than its normal counterpart which suggests a chronic condition.
King AC (2008)
Testicular Fibrosis.
The left, retained testis shows testicular fibrosis (22 grams). The contralateral testis is normal (250 grams).
Roberts SJ (1972)
Seminoma.
This equine seminoma is unilateral and caused testicular enlargement.
Roberts SJ (1972)
Strongyle Larva.
There is a small arch-like strongyle larva in the left upper half of the cross section of this retained testicle.
Roberts SJ (1973)