Excysts in the duodenum, feeds on mucosal wall and causes significant damage, migrates up the GI tracts to the rumen where it attaches to the rumen wall and feeds on rumen fluid- not pathogenic at this stage

Disease = Fasciolosis can be acute due to large number of migrating fluke, subacute- combination of immature and adult and chronic - adult fluke feeding on blood.

Mazeri et al., 2017 - modelling suggests that beef cattle infected with live fluke take longer to fatten >10 flukes = 77 extra days

Bovine tb skin test and blood test are less sensitive in liver fluke infected cattle, this is due to fluke suppressing the immune system resulting in a smaller reaction to the bTB tests. The same immune supression may increase susceptibility to salmonella and clostridium infections.

How ell et al., 2015 - exposure to liver fluke associated with lower milk yields

Sheep are less tolerant of fluke infection - historic problem known as black disease - clostridium novyi usually in gut but some can lodge in the liver where they remain dormant until damage occurs creating anaerobic conditions in which they can germinate causing necrosis and widespread damage - results in subcutaneous bleeding and blackening of the skin.

Can cause disease and mortality but official cases remain rare as massive juvenile stage infection is required

Increasing in prevalence - 51% of welsh farmers had not heard of rumen fluke - yet it was present on 61% of farms studied had cases.

Snail hosts like mild winters and wet summers- climate change having a major effect

Ollenshaw index used to predict liver fluke risk across the UL, work has shown that the same index has an association with rumen fluke distribution in welsh herds - Fox et al., 2011- predicted a huge increase in the severity of fluke outbreaks by 2070 with some areas of wales having serious epidemics and cases occurring in winter as well as summer