Clinical Examination of Farm Animals - CYF MEDICAL DISTRIBUTION

CHAPTER 11
age to the tunica albuginea may occur if the bull or
heifer moves suddenly during service. Caudal to the
scrotum, parts of the sigmoid flexure may be palpable
in younger bulls and older bulls who are not overweight.
Very occasionally, damage to the tunica
albuginea may also occur in this area. The penis is seldom
palpable as it leaves the pelvis and runs down
the perineum towards the sigmoid flexure.
Prepuce This is situated on the ventral surface of
the body running forward from the neck of the scrotum
to a point near the umbilicus. It is covered in a
loose layer of skin and lined by a mucous membrane
which is reflected onto the surface of the penis. When
the penis is fully retracted, the prepuce forms a sac
25 to 40 cm in length. During penile erection the sac
is everted and the mucous membrane extended and
exposed.
The preputial orifice, which has a sphincter, is found
on the anterior end of the prepuce. It is surrounded
by long hairs which are usually damp. If the animal
is suffering from urolithiasis the hairs may be dry with
adherent uroliths. This condition is discussed under
the renal system (Chapter 9). A purulent preputial
discharge may indicate infection of the prepuce.
In cases of balanoposthitis, some of which are associated
with infectious bovine rhinotracheitis/infectious
pustular vulvovaginitis/infectious pustular
balanoposthitis (IBR/IPV/IPB) infection, the prepuce
and penile surface may become severely inflamed
and ulcerated. The area is painful to the
touch, and the bull may become unwilling or unable
to extrude or retract his penis. In some bulls, especially
those at AI stations, the preputial mucosa may be
periodically everted but retracts fully if the bull is
disturbed. If the preputial mucous membrane is exposed
to the air for long periods or is damaged, it
readily becomes dry and infected. Withdrawal then
become difficult or impossible.
The prepuce should be examined and palpated
from its origin near the scrotum to its orifice. Soft,
fluctuant and sometimes painful swellings at its anterior
end may be caused by subcutaneous abscesses.
Firm caudal swellings caused by local enlargement of
the underlying penis just anterior to the scrotum may
be caused by rupture of the tunica albuginea of the
penis (‘fractured penis’). This is also discussed above
under ‘Penis’. These swellings can be more fully investigated
with the help of ultrasound, and in some
cases by needle aspiration and identification of
contents.
Rectal examination
This is an important and essential part of the examination
of the genital system of the bull. It enables the
accessory sexual organs which are situated mainly
on the pelvic floor to be examined and appraised
(Fig. 11.8). These structures are rarely involved in disease,
but may individually or together become infected
with serious consequences for semen quality
and fertility. They should be methodically examined
in the bull, commencing with the pelvic urethra to
which the other structures may be readily related.
Pelvic urethra This is readily palpable in the midline
of the pelvic floor as it runs backwards from the
neck of the bladder to the perineum. It is firm and
non-compressible. Pulsations can be felt when the
animal is passing urine or attempting to pass urine,
and may be induced by palpation.
Ampullae of the vas deferens These are palpable as
firm tubes 4 to 8 mm in width as they pass round the
anterior border of the pubis and enter the dorsal wall
of the urethra adjacent to the seminal vesicles. They
can be moved slightly in a lateral direction and are
normally non-painful to the touch.
Bovine prostate gland The prostate gland has two
parts. The body is a firm, smooth, elastic structure approximately
1 cm long (anteroposterior size) and
2 cm in width. It is a saddle-like structure which is
readily palpable as a protuberance on the cranial
part of the pelvic urethra. The disseminated part of
the prostate surrounds the pelvic urethra and is
not normally identifiable. The bovine prostate is
rarely involved in disease, but if inflamed the body
may be painful to the touch.
Bulbourethral glands These are small, paired and
situated at the caudal end of the pelvic urethra just
before it turns ventrally to run down the perineal
area. The glands are usually covered by the bulbospongiosus
muscle and are rarely palpable.
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