Changes

Measurement of serum glutamate dehydrogenase  (GLDH) and/or glutamyl transpeptidase (GGT) levels may prove useful. GLDH is an enzyme released by damaged hepatic cells and becomes elevated within the first few weeks of infection. GGT indicates damage to the epithelial cells lining the bile ducts and rises later in disease, although high levels are maintained for longer. Fluke serology is possible by means of a reliable ELISA test that identifies anti-fluke antibodies in the serum or in milk.

Measurement of serum glutamate dehydrogenase  (GLDH) and/or glutamyl transpeptidase (GGT) levels may prove useful. GLDH is an enzyme released by damaged hepatic cells and becomes elevated within the first few weeks of infection. GGT indicates damage to the epithelial cells lining the bile ducts and rises later in disease, although high levels are maintained for longer. Fluke serology is possible by means of a reliable ELISA test that identifies anti-fluke antibodies in the serum or in milk.

===Pathology===

===Pathology===

[[Image:Fasciola  hepatica - bile duct.jpg|150px|thumb|right|Bile duct fibrosis due to chronic ''Fasciola hepatica'' infestation. Source: Wikimedia Commons; author: Flukeman]]

[[Image:Fasciola  hepatica - bile duct.jpg|150px|thumb|right|Bile duct fibrosis due to chronic ''Fasciola hepatica'' infestation. Source: Wikimedia Commons; author: Flukeman]]

In acute fasciolosis, immature flukes grow and migrate within the liver parenchyma, causing necrotic tracts and haemorrhage. On post-mortem, the liver is enlarged and a fibrinous peritonitis may be be present. Fibrin takes are often particularly apparent on the ventral lobe. Histologically, tracts are seen as areas of degenerate hepatocytes and haemorrhage, which may later become infiltrated with eosinophils and lymphocytes. In the long term, these areas will become fibrosed.

Chronic fasciolosis is associated with damage to the bile ducts by adult flukes. On post-mortem, the liver is distorted by areas of fibrosis caused by the migration of the original immature flukes. The bile ducts are dilated, and flukes may be expressed from within. The gall bladder may also be enlarged. The walls of the bile ducts may be ulcerated and haemorrhagic with areas of epithelial hyperplasia. The walls eventually become fibrosed and may calcify in cattle. Calcified bile ducts can be seen protruding from the liver surface - this is known as "pipe stem liver".

 

 

This  is caused by  ingestion of metacercariae over a longer period of time.  Some may have  migrated to the bile ducts, causing [[cholangitis]],  whilst other  metacercariae are migrating through the liver causing  lesions similar to  those present in acute fascioliasis.  The infected  host may present  with severe haemorrhagic anaemia, with  [[hypoalbuminaemia]], rapid loss  of body condition, reduced appetite,  pale mucous membranes, and  submandibular oedema may also be present. On post-mortem, an enlarged  liver is common and haemorrhagic tracts are  usually visible on the liver surface. If left untreated, it is often  fatal.  This form of  fascioliasis occurs around 6-10 weeks after  ingestion of the  metacercariae by the host, and like acute fascioliasis  occurs in late  autumn and winter.

 

 

 

 

**Chronic inflammatory responses → fibrosis of  bile duct wall (and, in cattle, calcification)

**Gamma  glutamyl transpeptidase released by damaged cells

 

 

 

Infected  animals may present with progressive loss of body  condtion, reduced  appeptite, which along with hypoalbuminaemia can  result in an gaunt  animal. Other common signs include pale mucous  membranes, and  submandibular oedema, more commonly known as 'bottle  jaw.'  On biopsy  the liver will have an irregular shape, distorted shape  with areas of fibrous tissue replacing the cells damaged by the  migrating flukes. The bile ducts appear dilated, and dark, and it is  often possible to  express numerous numbers of adult flukes from within the ducts. Pathology is similar in both sheep and cattle, expect in  cattle you may see calcification of the bile ducts, and enlargement of the gall  bladder. The calcified bile ducts are often seen protruding from the liver surface, which is known as 'pipe stem liver.'

==Treatment==

==Treatment==