Echinococcus (E.) multilocularis does not only infect foxes as definitive hosts, but also dogs and cats; it is present in Central Europe (particularly southern Germany, northern Switzerland and western Austria), West and East Europe and focally in Scandinavia. Definitive hosts of E. granulosus are dogs and other canids. E. granulosus is mainly detected in the Baltic States, East and South Europe, including the Mediterranean, and is very rare in other places.
For the definitive hosts, echinococci are harmless intestinal parasites, whereas in intermediate hosts (herbivores and omnivores), metacestode cysts are mainly formed in the liver and lungs, even in humans as accidental hosts. In cystic echinococcosis caused by E. granulosus, encapsulated lesions are formed. In alveolar echinococcosis caused by E. multilocularis, in contrast, cysts show invasive growth with metastasis, so that the disease will lead to death if untreated.
There is a higher risk of echinococcus infestation and excretion of tapeworm eggs in dogs that eat rodents or that are used for fox hunting in dens. In Germany, echinococcosis is a notifiable disease.