Changes

[[Image:Fasciola  hepatica.jpg|thumb|right|150px|''Fasciola hepatica - Wikimedia Commons]]

[[Image:Fasciola  hepatica.jpg|thumb|right|150px|''Fasciola hepatica - Wikimedia Commons]]

[[Image:Fasciola  hepatica adult.jpg|thumb|right|150px|''Fasciola hepatica'' adults from a  horse - Castellà Veterinary Parasitology Universitat Autònoma de  Barcelona]]

[[Image:Fasciola  hepatica adult.jpg|thumb|right|150px|''Fasciola hepatica'' adults from a  horse - Castellà Veterinary Parasitology Universitat Autònoma de  Barcelona]]

For instance, wet summers increase both the number of snail habitats and the hatching of fluke eggs, leading to many infected snails. These in turn shed many cercariae, which form a high density of metacercariae on herbage to increase the risk of fasciolosis. Conversely, in dry summers, fewer fluke eggs hatch and snails are restricted to their permanent habitats. Fewer snails become infected and cercariae and metacercariae numbers are low and confined to the areas where snails can survive. The risk of fasciolosis is therefore reduced.

For instance, wet summers increase both the number of snail habitats and the hatching of fluke eggs, leading to many infected snails. These in turn shed many cercariae, which form a high density of metacercariae on herbage to increase the risk of fasciolosis. Conversely, in dry summers, fewer fluke eggs hatch and snails are restricted to their permanent habitats. Fewer snails become infected and cercariae and metacercariae numbers are low and confined to the areas where snails can survive. The risk of fasciolosis is therefore reduced.

 

A slightly larger trematode,  ''F. gigantica'', causes a similar condition in  tropical regions.

 

 

 

 

 

 

 

A similar but slightly larger species,  ''F. gigantica'', occurs in  wetter tropical regions.

==Signalment==

==Signalment==