ANIMAL HEALTH Beware of hydatid disease

Hydatid disease or echinococcosis is a parasitic disease caused by the tapeworm. It affects livestock, dogs and humans, and can be very dangerous to people living in close contact with animals.

As with all tapeworms, the hydatid worm (Echinococcus granulosus) requires both an intermediate and a final host to complete its cycle. Dogs (but not cats) and other animals are the final hosts in which the adult tapeworm is found, while the larval (immature) stages occur in the form of cysts in herbivores such as cattle, sheep, goats and game.

Humans can also accidentally act as an intermediate host.

LIFE CYCLE

The adult tapeworm occurs in the small intestine of dogs and other animals.

Between 2mm and 6mm long, the tapeworm consists of a head with hooks and suckers that attach the worm to the wall of the small intestine of the animal; a neck where growth takes place; and a body of three to seven segments that produces eggs.

Each segment has both male and female sexual organs, which means that a single worm can reproduce on its own. As the segments become ripe (filled with eggs), they are pushed to the tail of the worm.