Heterakis gallinarum

Heterakis gallinarum (the "cecal worm"), invades the ceca of chickens, ducks, geese, grouse, guinea fowl, partridges, pheasants, quail, turkeys, and other birds. It is a small, white worm that as mature, is between 7-17mm (0.27-0.67in) in length. The main importance of H. gallinarum infection is its role in the development of histomoniasis, often referred to as blackhead disease. H. gallinarum serves as a host for the protozoan parasite, Histomonas meleagridis, which causes histomoniasis.

Life cycle: H. gallinarum take 24 days to grow from larvae to adult. As adults, they begin laying eggs which are shed in the feces of infected birds. Eggs take 12-15 days to become infective and will hatch within 1-2 hours of ingestion by chickens.



  • Order: Ascaridida
  • Family: Ascarididae
  • Genus: Heterakis


  • chickens
  • ducks
  • geese
  • grouse
  • guinea fowl
  • partridges
  • pheasants
  • quail
  • turkeys