Volume 22 • Issue 03 • 2018
Field Vasectomy in Rams
(Herbst Technique)
Dr Francois van Niekerk
Humansdorp Veterinary Clinic
01
Place ram in sitting position on table
[mules bed/cradle works well, so does
a wheelbarrow, deep type, used by builders for
concrete].
02
With sheep shears shear/clip wool on
abdomen cranial to scrotum [about
10cm] and on cranial aspect of the neck of the
scrotum.
03
The surgical area is the cranial aspect of
the neck of the scrotum prepare the site
for surgery.
04
With lignocaine produce a line block
about 6 cm long in the median plane and
infiltrate the subcutaneous tissues.
05
groove.
06
Make a single incision about 4 - 5cm
long in the median plane over the scrotal
Dissect through the subcutaneous tissues
[tunica dartos, spermatic fascia and
tunica vaginalis (parietal layer)] into the vaginal
cavity, until a sterile finger can be inserted
into the incision and hooked around the right
spermatic cord.
07
Lift the spermatic cord into the incision
and identify the ductus deferens by rolling
between thumb and finger. It is about matchstick
thickness and has a firm cord-like character.
Carefully incise the mesorchium [mesoductus
deferens] over the duct avoiding the blood
vessels associated with the duct and the large
adjacent pampiniform plexus. [The mesorchium
is a fold of the tunica vaginalis which covers the
spermatic cord. The mesoductus deferens is that
portion of the mesorchium which suspends the
ductus deferens.]
08
09
Dissect the duct free with scissors,
exerting gentle traction.
After having achieved maximum
exteriorization of the duct, apply gentle
traction and clamp the proximal end of the freed
duct against the dorsal end of the incision with
mosquito forceps. Transect the duct proximally
and repeat distally thus removing about 7 – 12cm
of duct depending on the size of the ram.
10
Repeat the procedure on the left cord.
11
12
With a puffer bottle squirt wound
powder into the wound
Close skin incision
with a simple
continuous nylon suture [the tunica
vaginalis (parietal layer) need not be sutured].
DISCUSSION
Trengrove [JSAVA 36(1), 1965] described an
apparently commonly used method using a
caudal approach to the scrotum with the ram
lying on its side. However, the advantages of the
Herbst technique [so named after well-known
sheep practitioner, Dr Ian Herbst of Caledon] are
i.
It is easier and thus quicker to isolate the
duct and incise over it in the wound than
through the skin. Especially on the ram’s left
for a right-handed person and vice versa.
ii. The dirty under-side of the scrotum need not
be handled.
iii. A long piece of duct can be removed [7 –
12cm], thus obviating the need for tying off
the duct.
11