Clinical Examination of Farm Animals - CYF MEDICAL DISTRIBUTION

CHAPTER 10
Rosebud-like protrusion
of the cervix into the
anterior vagina
External os of
the cervix
Vaginal wall
Figure 10.8 The bovine cervix as viewed through a
vaginal speculum.
Such laceration may only be visible when the vagina
is distended with aspirated air. In the non-pregnant
cow the cervix is closed but opens slightly when the
animal is in oestrus.
The vaginal lumen should normally be empty and
any contents may be pathological. In cases of urovagina
urine runs forward from the external urethral orifice
pooling in the anterior vagina where it partially
or completely covers the cervix preventing successful
conception (Fig. 10.9). The clear thick mucus of
the bulling string may be seen through the speculum
in animals examined during oestrus. It is much thicker
than obstetrical lubricant from which it is easily
distinguished. A red watery metoestral discharge
may be seen 48 hours after oestrus. Awhite or creamy
white discharge coming through the cervix and pooling
on the vaginal floor is seen in cases of endometritis
and pyometra.
CLINICIAN’S CHECKLIST – VAGINAL
EXAMINATION
Vaginal walls
Vaginal contents
Cervix
(4) Special diagnostic tests
These are only necessary in a few cases of diseases
involving the female genital system. They are described
in summary form below, together with some
of their uses.
Milk (or plasma) progesterone assay
This can be used to confirm the presence of an active
corpus luteum in one of the ovaries. Elevated progesterone
is also seen in luteal ovarian cysts, in cases of a
mummified fetus (see below) and in pregnant animals
19 to 23 days after service. Falling progesterone
levels may be seen in failing pregnancies. Cows correctly
diagnosed as being in oestrus have very low
progesterone levels. Progesterone can be detected
qualitatively or quantitatively in either milk or plasma
using an ELISAtest. Aprogesterone level of more
than 5 ng per millilitre is regarded as being positive.
Oestrone sulphate test
This can be used to confirm the presence of a pregnancy
of more than 105 days in cattle. The test is
useful in cows in which the pregnant uterus is not accessible
to palpation per rectum because of adhesions,
or if transabdominal ultrasonography is not
available.
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