Scrotal hernia after castration

Keywords: castration, hernia, surgery, equine

The scrotum of a stallion that herniated an intestinal loop into its scrotum three weeks after an open-type castration.

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The intestinal contents occupied the empty scrotum (red arrows). Fortunately the scrotal incision had healed sufficiently to prevented evisceration and probably, death. Herniorrhaphy was performed on this stallion.

Closed castration with double transfixing ligation of the inguinal canal will usually prevent this problem from occurring. When the inguinal canal is left open to the exterior, the risk of fatal evisceration always exists.

Congenital scrotal hernia

Keywords: hernia, foal, ultrasound, surgery

A foal, approximately 30 days old was presented with a scrotal hernia. Ultrasonography was used to verify the presence and severity of the hernia.

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When intestines become entrapped within the vaginal cavity, edema and peritoneal fluid usually accumulate around the herniated intestines.  Together with the movement of intestinal contents, the ultrasonographic contrast provided by this fluid facilitates a diagnosis of an intestinal hernia.

Although this initially appeared to be a left-sided hernia, intestines had actually herniated into the right vaginal cavity, displacing the left side of the scrotum far out to the left side. This had created the initial impression of a left-sided hernia.

Copyright: Dr N. J. Vos email: Klaas_Vos@Hotmail.com.

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Herniorrhaphy was performed.  The head of the foal is at the top of the image above. The left testicle (green ring) was removed and the hernia on the right side was reduced via the abdominal route. A bizarre turn of events occurred during herniorrhaphy when the owner insisted that the testicle on that side not be removed! Despite warnings of potentially compromised blood supply and the heritability of scrotal hernias, the owners wishes were respected.

As reviewed by C.A. Ragle in Advances in Equine Laparoscopy (ISBN: 978-0-470-95877-3) scrotal hernias appear to be heritable in horses although a heritability coefficient has not been established as it has in pigs. This is complicated by the fact that scrotal hernias are more common in some breeds (Quarter horses and draft breeds) than others. That fact alone supports a heritable basis for the condition.

Anatomy of a scrotal hernia

Keywords: anatomy, scrotum, inguinal, stallion, hernia

Image size 1200 x 1600 px

The left inguinal canal and vaginal cavity of a newborn Jack (male donkey) viewed from a cranial-oblique aspect i.e. the head of the animal is to the left of this image.

A roll of green plastic about 7 mm in diameter has been placed in the inguinal canal, from the abdomen, through the internal inguinal opening and into the tunica vaginalis, which has been opened. The visceral vaginal tunic (v) is essentially the outer covering of the testicle. The ductus deferens (vas deferens) is indicated by the black arrow emerging into the abdomen from the internal opening of the inguinal canal.

When a scrotal hernia develops, intestines usually occupy the same space as that occupied by the roll of green plastic in this illustration. This is called an "indirect" hernia after nomenclature used in human medicine. In humans, so-called "direct" herniation occurs when the intestines move into the scrotum but lie in the interstitial tissue, outside the tunica vaginalis. "Indirect" herniation is far more common in stallions than "direct" herniation, sometime leading to confusion in veterinary medicine because the term "direct" carries with it an intimation of "simple" or "common".

A scrotal hernia

Keywords: equine, stallion, hernia, scrotum

Scrotal hernia of the small intestine in the right half of the scrotum in a stallion.

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This hernia was not obvious on casual observation or palpation but was easy to appreciate using trans-scrotal ultrasonography. The owner elected to have the horse euthanized and these pictures were taken shortly after euthanasia. The hernia opening was very tight, hardly permitting the insertion of a single finger, suggesting that loops of bowel can pass through very small inguinal openings indeed!

Occasionally these hernias are temporary and resolve spontaneously after a brief period of severe pain. In rare cases they can even be corrected via rectal palpation and traction. Ultimately however, loops of bowel become trapped in the tunica vaginalis and surgery is usually necessary.

Scrotal hernia in a stallion

Keywords: stallion, scrotum, hernia, testicles, colic

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An 11-year-old Standardbred stallion with anorexia, acute abdominal pain and large volumes of gastric reflux, was found to have a markedly enlarged left scrotum; approximately 22 cm x 11 cm x11 cm.  The stallion had a history of successful breeding in the current season.

Examination via trans-scrotal ultrasonography revealed the presence of fluid (f) surrounding the testicle (t) and a loop or loops of bowel containing gas (g) or no gas (ng) as indicated by highly echogencic foci. Peristalsis was not seen in the entrapped loops of bowel. Via transrectal palpation, a loop/s of bowel could easily be palpated entering the internal inguinal opening. Collectively, these findings led to a diagnosis of left inguinal hernia.

Inguinal hernias are not uncommon in stallions. Occasionally they will resolve spontaneously but will often recur. Surgery is required in all cases of inguinal herniation. Frequently it is necessary to remove the affected testicle while the inguinal canal is ablated. In such cases, the remaining testicle undergoes compensatory re-hyperplasia, allowing spermatogenesis to return to about 85% of its previous capacity.