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LIVER
DISEASES The
liver is a vital, complex organ which performs a number of crucial functions,
principally involved with metabolism and is sometimes termed the "factory
of the body" which controls many of the chemical processes necessary for
normal bodily function. For
example, the liver manufactures many essential substances, such as proteins,
bile and blood clotting factors, plays a role in controlling the metabolism and
use of food substances - fats, carbohydrates and proteins - as well as removing
many waste substances and potentially damaging drugs or chemicals. Therefore
disease problems can affect the liver in many ways and a diverse range of
clinical signs can develop. What
signs will you notice in a cat with liver disease? Some
signs raise a strong suspicion of liver disease - most notably jaundice which
appears as yellow discoloration of the skin, eye and mucous membrane, and
ascites, which appears as distension's of the abdomen due to build-up of fluid.
These are often accompanied by less specific signs which can be quite
variable including lethargy and malaise, changes in appetite, weight loss,
vomiting and diarrhoea. These may
be the only signs noted in some early or mild cases of liver disease. How
is liver disease recognised? In
mild or early cases of liver disease the signs are often relatively non-specific
and further investigations will be necessary to identify its presence.
Since the liver is responsible for such a diverse range of metabolic
functions there is a wide range of blood and urine laboratory tests which can be
used to assess liver disease. These
tests may also play a role in diagnosing liver disease as the cause of jaundice
and ascites since both these signs may be caused by diseases not involving the
liver. X-rays and scans may also be
of help by showing any changes in the size or appearance of the liver. Further
investigations of liver disease A
wide range of disorders may affect the liver resulting in abnormal liver tests
and there can be considerable overlap in the signs that cats affected with these
different diseases develop. In some
cases a specific diagnosis depends on microscopic examination of a small biopsy
of the liver which may be important in deciding on the most appropriate
treatment. Only a small fragment of
liver is needed for the biopsy and this can be collected using several different
approaches. This may involve
introducing a biopsy needle through the skin directly into the liver or via an
exploratory operation. Which
technique is used will depend on a number of factors.
In any animal there is always a slight risk associated with anaesthesia/sedation
and biopsy. This risk may be
slightly increased with some forms of liver disease.
Nevertheless the technique can be performed safely in most patients
without any significant complications. Treating
liver disease Specific
treatment for the particular liver disease will depend on what liver disease is
diagnosed. Some supportive measures
may also be recommended in some cases. Adjusting
the diet may be one measure. The
traditional view is to provide a diet which “reduces the load” on the liver
which is involved in the metabolism of most major food substances.
However, the most appropriate way of doing this in cats in not clear. Reduction of protein intake can be beneficial for some liver
problems but some protein intake is essential and the overiding priority is that
the cat should eat something. Palatability
may therefore be a major consideration in the choice of food for cats with liver
disease that have a poor appetite. High
quality protein is important. Carbohydrate
levels should be minimised but the benefit of reducing fat levels in the diet
which is recommended for most other species with liver disease, is questionable
for cats. Special prescription
diets have been formulated for cats with liver disease and you may be asked to
feed your cat one of these. |