ABSTRACT
The echinococcus or hydatid cyst represents the larval stage of Echinococcus granulosus, a 2-6 mm long tapeworm. In the adult stage the tapeworm lives in the gut of the dog, the definitive host. The intermediate animal hosts, where the parasite lives and develops at the larval stage, are sheep, cattle, pigs and man (considered an ‘accidental’ intermediate host). There are also ‘sylvatic cycles’ of echinococcus which occur in Canada, Alaska, Australia and other countries with different definitive and intermediate hosts according to the local prevalence of animal species.
