Clinical Examination of Farm Animals - CYF MEDICAL DISTRIBUTION

Clinical Examination of the Gastrointestinal System
Figure 8.24 Sites at which to perform an
abdominocentesis.
A
B
1
2
Xiphoid
Umbilicus
Ventral anterior site
Ventral posterior site
A
1
B
2
toneum and may not always be sampled during
abdominocentesis.
There are several potential sites at which to perform
an abdominocentesis (Fig. 8.24). Acommon site
is in the ventral anterior abdomen midway between the
xiphisternum and the umbilicus in the midline. This
site is easy to identify and carries no risk of accidentally
puncturing the milk vein. An alternative site in
the anterior abdomen is 5 cm caudal to the xiphisternum
and 5 cm to the left or right of the midline. Care
is required to ensure that the milk vein is not punctured
if close to the site. Other sites are on the left or
right posterior abdomen just anterior to attachment of
the mammary gland to the body wall.
The preparation and the procedure are the same at each
site. Ideally, hair is clipped or shaved at the site and
the skin aseptically prepared. Restraint using a kinch
or an antikick bar can improve operator safety. A5 cm
19 BWG (1.10 mm) needle is gently pushed into the
peritoneal cavity of the abdomen through the skin,
musculature and parietal peritoneum. If no peritoneal
fluid is obtained the needle can be rotated and
the degree of penetration increased. In ventral sites
the rumen is sometimes penetrated and a dark gritty
sample obtained. If no sample is obtained a new site
should be selected. Applying a syringe to the barrel
of the needle and applying gentle suction may be
useful. Samples should be collected into plain tubes
for bacteriology and EDTAtubes for cytology.
Peritoneal fluid analysis
Examination of the sample includes assessment of
the volume, colour, viscosity, turbidity, cell number
and type, specific gravity and protein concentration,
preparation of stained smears for visualisation
of bacteria and bacterial culture. Samples can be
sent off to the laboratory for detailed analysis, but
useful information can be obtained inexpensively
from gross examination of the sample and simple
microscopy.
The volume of a sample obtained from healthy
cattle ranges from 0 to 5 ml. Volumes of 10 ml or
above may indicate a pathological process unless
the animal is in late pregnancy.
The colour of normal peritoneal fluid is clear, straw
coloured or yellow. If the sample is green in colour
this suggests the presence of food material and may
indicate a gut rupture or that a gut sample (a rumen
sample being the most common) has inadvertently
been obtained. Repeating the abdominocentesis at a
different site may help confirm the result. If the sample
is an intense orange-green colour this indicates
rupture of the biliary system, but this is very rare. A
pink to red sample indicates presence of haemoglobin
and/or red blood cells which may indicate the iatrogenic
penetration of a blood vessel, a gut infarction or
perforation. A red-brown colour indicates necrosis of
the gut wall. Asample consisting of frank blood indicates
haemorrhage into the peritoneum (haemoperi-
107