Testicular torsion with hydrocele
Keywords: testicle, torsion, hydrocele, equine
Image size: 1800 x 1213px
Caudal view of a three year old Standardbred stallion presented for castration after discomfort during exercise. Examination revealed a right-sided hydrocele (fluid accumulation in the vaginal cavity surrounding the testicle). Testicle torsion was ascertained by palpation and ultrasound (inset) and confirmed during surgery. Bilateral castration was performed.
It is not clear how testicular torsion develops in stallions because the mesorchium is usually a short ligament between the parietal and visceral vaginal tunics, running the entire length of the dorsal aspect of the testicle (the testicle is suspended horizontally in equids). Therefore testicular torsion should in theory, be almost impossible. It does however, occur. Perhaps the mesorchium may stretch under some circumstances (such as hydrocele in this case) allowing the testicle to rotate horizontally on its dorsoventral, transverse axis. This has certainly be shown to be the case in humans, where testicular torsion in not rare.
The question remains: In this case, was the hydrocele a primary condition, allowing torsion in this case or was it secondary to the torsion? There was neither overt strangulation nor vascular embarrassment of the spermatic cord; not enough to cause tissue necrosis but perhaps enough to cause hydrocele.
In some cases testicle torsion appears to be partial, congenital and is innocuous, causing neither infertility nor vascular embarrassment.
Reference:
Wyatt J. K. and Mundy H. B. 1972 Torsion of the testicle: a clinical review of 20 cases, Can Med Assoc J. 107: 971–973
