Liver Liver

Most liver function tests usually remain normal in geriatric patients and this probably reflects the huge reserve capacity of this organ, however, in humans bromsulphalein (BSP) retention does increase with age.

Hepatic lipidosis is common in cats, and may or may not be associated with obesity. Up to 50% of liver biopsies taken from cats in the USA are reported to demonstrate lipidosis on histological examination (Davenport 1991 personal cornmunication). This condition can be secondary to diamellitus, hyperadrenocorticism, hypothyroidism or protein-energy malnutrition and affected animals may show gross hepatomegaly, elevated liver enzyme concentrations (serum alanine aminotransferase (ALT) and alkaline phosphatase (AP) and disturbances of liver function.

Cirrhosis is a chronic progressive disease usually affecting older animals resulting in loss of parenchymal mass and therefore reduced function. Primary and secondary hepatic neoplasia may also occur, eventually causing reduced liver function.

In the presence of impaired hepatic function the plasma clearance rate for drugs may be decreased resulting in increased duration of action. At the same time drugs and nutrients that need to be converted to an active form by the liver may exhibit reduced activity.