Atlas of livestock parasites
digitized collection of microscopical preparations

Atlas of Parasites Contents Information sources Glossary Administration

Moniezia expansa (sheep, cattle, camels)

Category:


Species:
Endoparasite


Description:
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Cestode    

 

"tapeworm"      

Distribution: Worldwide.   Species include M. benedeni and M. expansa.  Moniezia tapeworms are widely distributed in regions of cattle production. Of the two species, M. benedeni is seen more often in cattle.  

Host: Small intestine of ruminants and camelids.     

Life Cycle: Moniezia’s life cycle is the indirect one typical of tapeworms. Immature forms develop in many genera of oribatid mites - the intermediate host (free-living pasture mites) which eat the eggs. Cattle ingest the mites and digest them, releasing the immature tapeworm forms from which adult tapeworms develop. Ruminants are infected following ingestion of  containing the tapeworm larvae.         

Diagnosis: Worms are long, measuring up to 6 meters in length and 2.6 cm in width. Proglottids are much wider and grossly resemble grains of rice appear in the feces. Eggs found inside the proglottids are thick-shelled and imperfectly rounded. Eggs may be found in fecal flotation tests, but infection is usually recognized when owners see tapeworm segments on the animal or in the environment.    

Size: 65–75µm in diameter   M. expansa egg, thick shell, irregular shape, tri- or quadrangular, triangular to pyramidal, embryonated with pyriform apparatus.

Clinical features: Heavy worm burdens may compete with the host for ingested nutrients, resulting in decreased weight gain. In general, little clinical importance, although there are anecdotal reports that heavy infection may cause reduced growth in young animals. 

Moniezia tapeworms are widespread in cattle, but their actual economical significance is not known. Moniezia are easily seen in the intestine. In heavy infections, lower weight gain may reduce total weight at slaughter. Danger of intestinal obstruction is also a potential problem in calves with heavy infections.

Control: Reducing mite population is difficult. Anthelmintics effective against cestodes can be used.             


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Moniezia expansa
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