Changes

'''Definitive hosts''': Dogs and wild canids.

'''Definitive hosts''': Dogs and wild canids.

=== Life-Cycle ===

==Life-Cycle==

The final host of ''E. granulosus'' is the dog, fox or other canid. There may be several thousand adult tapeworms in an infected animal. Each adult is less than 0.5cm long with only 3 or 4 segments. The scolex is deeply buried in an intestinal crypt, so microscopic inspection of a mucosal scraping is necessary to detect infection. The prepatent period of ''E. granulosus'' is 6-7weeks. No more than one gravid segment is passed by each tapeworm each week. This species therefore has a low biotic potential. The intermediate host is infected by swallowing the eggs. These are half the size of a strongyle egg, and are morphologically indistinguishable from other taeniid eggs.

There may be several thousand adult tapeworms in an infected animal. The scolex is deeply buried in an intestinal crypt, so microscopic inspection of a mucosal scraping is necessary to detect infection.

The metacestode of ''E. granulosus'' is the hydatid cyst. These can develop anywhere in the body, but are most frequently found:

The terminal proglottid forms approximately half the total length. The proglottids are shed in the faeces. The oncosphere are capable of surviving in the environment, for up to two years.  They are then ingested by the intermediate host e.g. the sheep, where they penetrate the gut lining.

*sheep: liver and lungs

*cattle: lungs

The oncosphere then travels to the liver and the lungs, where the hydatid then begins growth.  This is a slow process taking around 6-12 months, and the cysts are capable of growing up to 20cm in length.

=== Prevalence in the UK: ===

=== Prevalence in the UK: ===