Clinical Examination of Farm Animals - CYF MEDICAL DISTRIBUTION

CHAPTER 8
Palpation and percussion
The liver lies beneath the costal arch and cannot normally
be palpated. If it is grossly enlarged or displaced posteriorly
it may be palpated by pushing the fingers behind
the right costal arch. The liver may be enlarged
in chronic liver fluke infestation and congestive heart
failure. The exact location of the liver can be confirmed
by percussion.
Ultrasonography
Using ultrasonography, the size, position and consistency
of the liver can be characterised and the presence
of abscesses may be confirmed. The gall bladder
lies on the caudal border of the liver but is seldom involved
in pathology, although it may be enlarged in
some cases of salmonellosis. The gall bladder can be
visualised using ultrasonography.
Clinical pathology and liver function tests
Liver function This can be assessed by using the
bromosulphophthalein (BSP) clearance test and the
gluconeogenic test using propionic acid. These tests
are described under ‘Further investigations’.
Clinical pathology This may be used to identify
liver disease. Biochemical changes such as hypoproteinaemia
occur in some types of liver disease. In disease,
the enzyme aspartate aminotransferase (AST)
may be elevated in the liver, but it is also produced by
other tissues including cardiac and skeletal muscle.
Sorbitol dehydrogenase (SDH) and glutamate dehydrogenase
(GLDH) are liver specific and are elevated
in the acute phase of disease. Gamma glutamyltransferase
(gGT) is a good indicator of bile duct damage
and is raised in liver fluke infestations. Bile salts
may be elevated in hepatic pathology. Conjugated
bilirubin increases with bile duct obstruction and
unconjugated bilirubin increases in haemolytic
anaemia. Indirect measures of liver function in cows
with fatty liver syndrome have been used including
non-esterified fatty acids, glucose levels and AST
levels.
Liver biopsy
A liver biopsy can be useful to characterise liver
pathology such as fatty liver syndrome and ragwort
poisoning in addition to trace element analysis, for
example for copper. The risks of severe iatrogenic
haemorrhage during and following this procedure
must be considered. This technique is described
under ‘Further investigations’.
Examination of the contents of
the peritoneum
Detection of excessive fluid in the abdomen by physical
means is difficult unless accumulations are large.
Distension of the abdomen due to ascites is uncommon.
The results of ballotting for a fluid thrill are
difficult to interpret because of the fluid content of
the ventral rumen. Abdominocentesis or ultrasonography
are usually more rewarding, and these techniques
are described under ‘Further investigations’.
Some characterisation of the fluid is possible with
ultrasonography. Transudates or urine in the peritoneum
can be identified as non-echogenic fluid images.
Floating leaves of oedematous omentum may
be present with a ruptured bladder. Peritonitis may
produce hyperechogenic tags of fibrin. Peritoneal
samples can be assessed by gross examination
or sent for laboratory analysis and bacteriological
culture. Interpretations are provided under ‘Further
investigations’.
CLINICIAN’S CHECKLIST – EXAMINATION
OF THE RIGHT SIDE OF THE ABDOMEN
Detailed examination of any contour abnormalities
Palpation and auscultation of the right body wall for
abnormal pings
Auscultation and succussion to assess intestinal motility and
content
Ballottement to identify normal and abnormal structures
Test for pain in the right ventral anterior quadrant
Check for enlargement of the liver by palpation
Liver clinical pathology
Assessment of the peritoneal cavity contents
Rectal examination
Rectal examination can be used to identify conditions
of the gastrointestinal and urogenital tracts.
The latter is described in Chapters 10 and 11. Rectal
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