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.
Figure 1. Cattle tapeworm (e.g. intestinal tapeworm, Moniezia benedeni) life cycle with cattle as the final host. Image created by Madison Mayfield
- 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.