Development and morphological variability of Echinococcus granulosus

Characteristics are presented of Echinococcus granulosus strobila from dogs experimentally infected with protoscolices from a single cyst isolated from the liver of a domestic pig in a central Slovakian district. Adult cestodes are characterized mainly by 28-32 hooks highly variable in shape and size; 26-51 testes situated mostly throughout the proglottis (1 or 3 rows behind the vitelline gland); a lobate ovary; the shape of the uterus, which in 10% of proglottides is more or less spherical, in 62% is saccular with lateral sacculations of variable size, in 27% is saccular without lateral sacculations and in 1% is more or less tubular or strongly ramified; and an intermediately rapid rate of development lasting until between 40 and 44 days p.i. The present report analyzes the high degree of variability of the clone studied, referring to the knowledge on the characteristics of the pig, sheep, and cattle strains of E. granulosus and E. multilocularis species, with which some taxonomic characters of the clone representatives overlap.