ISSN 2398-2993      



Ash Phipps

Andrew Forbes

Synonym(s): nodule worm




  • Phylum: Nematoda.
  • Order: Strongylida.
  • Family: Strongyloidae.
  • Genus: Oesophagostomum.
  • Species: Oesophagostomum radiatum and Oesophagostomum venulosum.

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Clinical Effects



  • Adults inhabit the gastrointestinal tract.
  • Eggs are passed in the feces.
  • L1 and L2 inhabit the feces.
  • L3 inhabit the feces and surrounding herbage.
  • L4 and adults inhabit the host’s gastrointestinal tract.


  • Prepatent period: 24-26 days if no larval inhibition.
  • Direct lifecycle.
  • Adult worms produce eggs which are passed in the feces of cattle.
  • L1 hatch from the eggs within the feces.
  • L1 develop to L2 and L3 in the feces.
  • L3 are infective.
  • Cattle eat ingest the L3 from the pasture.
  • The L3 larvae enter the proximal small intestinal wall and remain there for about approximately 5 days (hypobiotic stage 1).
  • The L4 larvae then re-emerge from the proximal small intestinal wall and are transported to the large intestine where they enter the large intestinal wall.
  • Some of the L4 will remain dormant (hypobiotic stage 2) and others will develop into adults.
  • The adults attach to the colonic mucosa and begin to produce eggs.
A second wave of ingested infective larvae results in majority of the larvae becoming arrested in the intestinal wall, at either hypobiotic stage.
  • Nodules (3-6mm in diameter) develop in the intestinal walls due to the host’s immune response to the hypobiotic larvae.  
  • During periods of which the animal’s resistance is lowered, such as poor nutrition or  immunosuppression, the hypobiotic larvae emerge into the small intestine lumen and travel to the large intestine to complete their development and to become adult worms.


  • Ingestion of the infective larvae.

Pathological effects

  • Young animals: adult worms generally exert the greatest effect on the host.
    • Clinical signs include: anorexia, severe diarrhea, edema (as a result of hypoproteinemia), weight loss, anemia and death.
  • Adult animals: the formation of nodules exerts the greatest effect on the host with synchronous emergence of larvae.
    • Clinical signs include: catarrhal colitis, malena and diarrhea.

Other Host Effects

  • As above.


Control via chemotherapies

  • Numerous broad spectrum anthelmintics (including benzimidazoles, levamisole Levamisole and avermectins/milbemycins) are effective against adult worms and inhibited larvae. The products available will vary depending on the country.

Control via environment

  • Avoid overstocking pens and paddocks.


  • No vaccine currently available.

Other countermeasures

  • Alternative countermeasures outlined for other nematode worm infections may also help to control Oesophagostomum spp infections.


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Further Reading


Refereed Papers

  • Recent references from PubMed and VetMedResource.
  • Van Wyk J A & Mayhew E (2013) Morphological identification of parasitic nematode infective larvae of small ruminants and cattle: a practical lab guide. Onderstepoort J Vet Res 80 (1), 1-14 PubMed.
  • Hutchinson G W (2009) Nematode parasites of small ruminants, camelids and cattle diagnosis with emphasis on anthelmintic efficacy and resistance testing. Australia and New Zealand standard diagnostic procedures, 22-26.
  • Fabiyi J P, Copeman D B & Hutchinson G W (1988) Abundance and survival of infective larvae of the cattle nematodes Cooperia punctata, Haemonchus placei and Oesophagostomum radiatum from faecal pats in a wet tropical climate. Aust Vet J 65 (8), 229-231 PubMed.
  • Bremner K C, Keith R K & Winks R (1976) Age resistance of cattle to the nodular worm Oesophagostomum radiatumRes Vet Sci 20 (3), 350-351 PubMed.
  • Williams J C & Mayhew R L (1967) Survival of infective larvae of the cattle nematodes, Cooperia punctata, Trichostrongylus axei, and Oesophagostomum radiatum. Am J Vet Sci 28 (124), 629-640 VetMedResource.
  • Keith R K (1953) The differentiation of the infective larvae of some common nematode parasites of cattle. Aust J Zoo 1 (2), 223-235 VetMedResource.

Other sources of information

  • Junquera P (2018) Oesophgostomum spp, nodular worms parasitic of cattle, sheep, goats and swine. Biology, prevention and control. Oesophagostomum radiatum, Oesophagostomum columbianum, Oesophagostomum dentatum. [online]. Website: Last accessed 23 January 2018.
  • Parkinson T J, Vermunt J J & Malmo J (2010) Diseases of cattle in Australasia: a comprehensive textbook. In: New Zealand veterinary association foundation for continuing education. pp 729.
  • Anderson D E & Rings M (2008) Current veterinary therapy e-book: food animal practice. Elsevier health sciences. pp 82.
  • Radostits O M, Gay C C, Hinchcliff K W & Constable P D (eds) (2006) Veterinary Medicine: A textbook of the diseases of cattle, horses, sheep, pigs and goats. Elsevier health sciences. pp 923-924.

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