Page 1379 - Equine Clinical Medicine, Surgery and Reproduction, 2nd Edition

1354 CHAPTER 14

VetBooks.ir 14.21 Aetiology/pathophysiology
At birth, many foals will have a defect in the body
wall at the umbilicus (palpable umbilical ring), which
becomes smaller and disappears over time. This
defect is a normal variant in foals and should not be
described as a congenital hernia until the foal is at
least 1 month of age. Acquired hernias are reported
to arise between 5 and 8 weeks of age. Hernias may
also develop following omphalitis or omphalophlebi-
tis. Intestinal incarceration within a hernia in a foal,
of whatever aetiology, is rare. The size and contents
of a hernia determine its significance as a clinical
problem. Larger hernial rings are less likely to close
spontaneously and have a greater chance of contain-
ing intestine or omentum.
Fig. 14.21 A foal with an acquired patent urachus,
showing a moist and swollen remnant of the umbilical Clinical presentation
cord through which urine is drained intermittently. The hernia is characterised by a visible and palpable,
non-painful swelling of the umbilicus, which is reduc-
ible on palpation (Fig. 14.22). The muscular edge of
Contrast cystography has been used in more obscure the defect is readily palpable. It may be detected soon
cases. A full blood analysis and clinical work-up after birth but is often only identified later in life
should be carried out. when the foal is suckling or weaned. The time of her-
nia detection depends on the age at which the defect
Management developed and the closeness of observation. There are
If there is no concurrent umbilical disease, many no other clinical signs unless there is abscessation or
cases of patent urachus will resolve spontaneously loops of bowel become incarcerated in the hernia, the
over time (usually within a few days, but sometimes
up to 14 days). Prophylactic broad-spectrum anti-
biotics should be administered concurrently. The
application of desiccating or cauterising agents to 14.22
the urachal opening to enhance closure is controver-
sial and generally not recommended because of tis-
sue necrosis. Any concurrent or underlying disease
should be treated. Surgical removal of the umbilicus
is rarely necessary and typically is only required if
there is concurrent and severe remnant infection,
internal abscessation or other complications (such as
urachal rent or bladder necrosis).

UMBILICAL HERNIA

Definition/overview
This is a relatively common abnormality due to fail- Fig. 14.22 A young male foal with a congenital
ure of the abdominal musculature to close around umbilical hernia. The hernial sac could easily be
the umbilicus (congenital), or it may occur as an replaced into the abdomen and did not contain
acquired body wall defect. intestine at any stage.