Umbilical Hernia

Do not confuse with:

Patent or Persistent Urachus

Description

Umbilical hernias occur at the site of umbilicus, the point at which the animal was previously joined to the placenta by the umbilical cord. Congenital hernias occur due to a failure of complete fusion between the embryological lateral folds, leaving a defect in the ventral body wall through which organs are able to herniate. Most umbilical hernias are small, reducible and cause few clinical signs. In some cases however, the hernia may contain intestine that becomes incarcerated and strangulated causing acute clinical signs. These hernias may occur with other congenital defects, including cardiac septal anomalies, bladder exstrophy, hypospadia, cryptorchidism and peritoneopericardial diaphragmatic hernias. The structures most commonly herniated are the omentum, falciform fat and intestine and they are contained with a hernial sac comprising the skin, the subcutaneous connective tissue and the parietal peritoneum.

Acquired hernias may form if excessive traction is applied to the umbilical stump before it has contracted completely or if the stump is ligated too close to the abdominal wall.

Signalment

Congenital umbilical hernias occur commonly in all of the major domestic species. It is generally recommended not to breed from male farm animals (bulls or rams) whose offspring often show this defect.

Diagnosis

Clinical Signs

A soft swelling will be palpable in the region of the umbilicus but not involving the umbilical vessels and remnant. Simple hernias should not be warm or painful to touch and if either sign is present, differential diagnoses such as umbilical abscess or omphalitis should be considered. In most cases, the hernia is reducible, especially if the animal is in dorsal recumbency.

If a loop of small intestine has become incarcerated and strangulated, the animals may be severely ill and show signs of:

• Vomiting' with acute onset
• Depression, lethargy and anorexia

If the intestine ruptures, septic peritonitis may develop with pyrexia and septic shock.

Laboratory Tests

Umbilical hernias are externally evident but changes will be detected on haematological and biochemical profiles if intestine id strangulated.

Diagnostic Imaging

Ultrasonography can be used to determine whether any structures lie within the hernial sac and to ascertain whether the umbilical structures are normal. Imaging can also be used to determine whether the animal suffers from any of the other congenital abnormalities.

Treatment

Surgical herniorraphy is the treatment of choice but, in most cases, this should be delayed for several months as many hernias close naturally over time.