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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".
 
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".
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==Treatment==
 
==Treatment==
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Due to the reliance of disease transmission on appropriate snail habitats and therefore weather, it has been possible to develop models to predict the occurence of fasciolosis to help its control within flocks and herds. These models evaluate the soil moisture content from May to October by considering rainfall patterns and evapo-transipration, weighted for season. Although June is a particularly influential month in these models, a drought in late summer can reverse predictions of potentially high snail density, and so forecasts should not be issued prematurely. A complicating factor in the prediction of fasciolosis is the fact that snail density is insufficient for disease in the absence of infection (i.e. deposited fluke eggs), and so forecasts generated must be interpreted in the context of local biology.
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Due to the reliance of disease transmission on appropriate snail habitats and therefore weather, it has been possible to develop models to predict the occurence of fasciolosis to help its control within flocks and herds. These models evaluate the soil moisture content from May to October by considering rainfall patterns and evapo-transpiration, weighted for season. Although June is a particularly influential month in these models, a drought in late summer can reverse predictions of potentially high snail density, and so forecasts should not be issued prematurely. A complicating factor in the prediction of fasciolosis is the fact that snail density is insufficient for disease in the absence of infection (i.e. deposited fluke eggs), and so forecasts generated must be interpreted in the context of local biology.
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Anthelmintic drugs are used in the control of fasciolosis. Not all flukicides are effective against each parasitic developmental stage, and so some may not be suitable for use in an outbreak of acute disease. Triclabendazole, a benzimidazole, is the flukicide with the broadest spectrum of activity against both immature and adult ''[[Fasciola hepatica]]'' and is therefore used to control acute disease. However, triclabendazole-resistant fluke populations are beginning to emerge.
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'''Anthelmintics'''
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*Few flukicides kill all parasitic developmental stages
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*Not all products, therefore, are suitable for controlling  acute outbreaks
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*The anthelmintic with the broadest  spectrum of activity against immature and adult ''F. hepatica'' is  '''Triclabendazole'''
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*Triclabendazole-resistant ''F.  hepatica'' populations are beginning to emerge
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*The more  potent products tend to be the most expensive
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*Many  flukicides bind to plasma protein and have long plasma half-lives
      
'''Chemoprophylaxis'''  
 
'''Chemoprophylaxis'''  
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