Cattle Tapeworm Life Cycle: Adult Worms in Cattle (herbivorous)

Cattle tapeworms (e.g. intestinal tapeworm, Moniezia benedeni) follow this basic indirect life cycle that involves a grass mite as the intermediate host and cattle as the final host.

Dung stage

• Tapeworms in the small intestine shed mature (ripe, gravid) segments or proglottids (sacs of eggs) that are passed out with the dung.
• Segments burst releasing eggs.

Intermediate host stage: grass mite

• Contents of tapeworm eggs are eaten by a grass mite.
• The worms develop in the grass mite and produce a cysticercoid type larvae (a cyst containing the ‘scolex’ head-end of the tapeworm).

Pasture stage: spreading of infection

Naïve (never been exposed) calves are infected by ingesting infected grass mites during grazing.

Final host stage in cattle: new infection and re-infection

Grass mites containing infective larval (cysticercoid) stage are eaten along with the pasture.

• Once ingested, the juvenile is released in the small intestine and develops into an adult tapeworm.
• Adults live for many months in the gut of cattle, reproduce and shed segments containing many eggs.
• Older cattle become immune to infection