Atlas of livestock parasites
digitized collection of microscopical preparations

Atlas of Parasites Contents Information sources Glossary Administration

Strongyloldes papillosus (cattle)



Untitled document

Strongyloldes papillosus
Intestinal threadworm

General Description:

Adults are short and thin, 3.5 to 6 mm long and only 0.05 to 0.06 mm wide.

Life Cycle:
Parthenogenetic female adults in the intestine lay eggs which do not need fertilization by sperm to develop. Larvae begin to form in them before passing in feces. On pasture the eggs hatch quickly and larvae molt to become infective third stage larvae in 24 to 48 hours (homogonic cycle); these infect animals by skin penetration or by ingestion. Strongyloides papillosus can cross the placenta, infecting calves before birth. These nematodes can also pass in colostrum to newborn calves. The circulation then carries the larvae to the lungs. After being coughed up and swallowed, they develop into adults approximately 7 to 9 days after infection. There may be a free-living stage in addition to the parasitic stage (heterogonic cycle).

Small intestine.

Geographical Distribution:
Worldwide, especially in warm, humid areas.

Intestinal threadworms are widespread, multiply rapidly, young animals are often infected.

Effect on Host:
Infective threadworms penetrate the host’s skin and migrate to the lungs where they damage tissue. Adults inhabit the intestine, causing severe inflammation and bloody diarrhea. Immunity develops to Strongyloides infections, and young cattle that do not have this resistance may be seriously affected.

Diagnostic Information:
Eggs are small and embryonated, already containing larvae when passed in feces.


Pasture management: drain pastures, keep barns dry. Treat cattle with anthelmintics.


No picture to show.

<<< Back