Diagnosis and Practical Treatment of Hepatic Disease

Diagnosis
As a result of the liver’s many functions, a diverse range of clinical signs (Table 1) can be seen with liver disease, none of which are pathognomonic. Biochemical testing can be used to further localise the cause of the signs to the liver (Table 2). Some of these tests are ‘liver specific’; however, beyond determining whether the abnormality is associated more with hepatocyte damage (increased SDH, AST) than cholestasis (increased GGT), a specific diagnosis cannot be made using blood work alone. As a result, further diagnostic testing will typically be required to help define the aetiology of the liver dysfunction, unless the history is strongly suggestive of a diagnosis (such as grazing Ragwort-infested pastures).

Ultrasound examination of the liver is the logical next step, although in many cases this will be normal. Ultrasound is most useful in diagnosing hepatic masses or abscesses, changes in echogenicity that may suggest a cellular infiltrate, for identifying choleliths and biliary stasis and for locating an appropriate biopsy site. Because of the location of the liver, being mostly ‘hidden’ behind the lungs, only approximately 20% of the organ can be imaged and, as a result, focal diseases may be missed. [...]