Page 581 - Equine Clinical Medicine, Surgery and Reproduction, 2nd Edition

556 CHAPTER 2

VetBooks.ir trauma or orchitis/epididymitis are detailed in the Differential diagnosis
All other causes of scrotal enlargement should be
corresponding sections.
Prognosis considered including cord torsion, trauma, haemato-
coele, scrotal hernia and neoplasia.
The prognosis is good. Recovery may be prolonged
in cases where there is considerable surgical dissec- Diagnosis
tion and tissue removal. Palpation of hydrocoele is reminiscent of palpating
a bag of fluid. The testes and epididymides may not
HYDROCOELE be palpable if there is considerable fluid accumu-
lation. Ultrasound examination reveals anechoic
Definition/overview or hypoechoic fluid accumulation between the
Hydrocoele is an abnormal accumulation of fluid testis and scrotal skin. An aseptic technique can
within the vaginal cavity, between the visceral and be used to obtain a sample of the fluid for cyto-
parietal layers of the vaginal tunic. It can occur with logical analysis and in hydrocoele, an amber-
or without accompanying scrotal oedema and may coloured sterile transudate (low cellularity) fluid is
be uni- or bilateral and temporary or permanent in obtained, although this carries the risk of bacterial
nature. contamination.

Aetiology/pathophysiology Management
The vaginal tunic secretes a serous fluid to lubricate In cases of idiopathic hydrocoele, drainage of the
the vaginal cavity, allowing movement of the testicle fluid is not usually effective, as it recurs quickly.
within the scrotum for optimal thermoregulation. Cases occurring during periods of hot weather sub-
Normally the fluid is reabsorbed by the lymphatic side when the weather cools. Moderate exercise may
vessels of the spermatic cord. Any condition caus- be helpful in alleviating fluid accumulation. Anti-
ing increased fluid secretion or decreased absorption inflammatory therapy and diuretics are generally of
will result in hydrocoele. Causes include inflamma- limited value. Most cases of idiopathic hydrocoele
tory and non-inflammatory conditions (e.g. trauma, will resolve spontaneously. Chronic hydrocoele can
neoplasia, orchitis and extreme hot weather), but the be treated by unilateral orchidectomy of the affected
condition is often idiopathic. Since the vaginal cav- side.
ity communicates with the peritoneal cavity, perito-
nitis or ascites can also cause hydrocoele. Chronic Prognosis
or severe hydrocoele can impact on fertility due to The prognosis is guarded and is dependent on reso-
the insulating effect of the fluid and the subsequent lution of the inciting cause. Most cases of idiopathic
effect on spermatogenesis. hydrocoele will resolve spontaneously.

Clinical presentation SCROTAL AND INGUINAL HERNIA
Affected stallions present with unilateral or bilateral
painless scrotal enlargement. Systemic signs such a Definition/overview
colic or pyrexia are absent. On palpation, the testis Scrotal and inguinal hernia involves herniation of
and epididymis are freely mobile within the scrotum, intestine and/or mesentery through the inguinal
and usually palpable unless a significant amount of canal, via the inguinal ring, into the vaginal cavity.
fluid accumulation obscures the identification of When the herniation extends into the scrotum, the
these structures. Ultrasound examination demon- condition is termed scrotal hernia. If the intestine
strates varying degrees of anechoic fluid within the has penetrated the vaginal tunic, as may occur in
scrotal sac. The testis and epididymis appear normal the male foal during parturition, the condition is
ultrasonographically. termed a ruptured inguinal/scrotal hernia.