Heterakis gallinarumnarum

Heterakis gallinarum Cecal Worms	Contents	Rev 10/25/2025
	Classification	Biology and Ecology
	Morphology and Anatomy	Life Cycle
Return to Heterakis Menu		Ecosystem Functions and Services
	Distribution	Management
Return to Heterakidae Menu	Feeding	References
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Classification:

Class: Chromadorea

Subclass: Chromadoria

Order: Rhabditida

Suborder: Spirurina

Superfamily: Heterakoidea

Family: Heterakidae

Heterakis gallinarum (Schrank, 1878) Madsen, 1949

Synonym:

Morphology and Anatomy:

Adults densely white and stout.

Males:

Length 3-8 cm, width 0.5-1.2 mm
Spicules somewhat unequal, 4 mm long.
Ellipsoidal or circular preanal sucker about 220 um in diam
Tail with narrow caudal alae.

Females:

Length 6-12 cm, widthe 0.9-1.8 mm.
Straight, conical tail.
Eggs ellipsoidal with a rather thick, smooth outer shell; 75-90 x 45-55; not embryonated when laid.

Ref: Cruthers et al., 2020

Reported median body size for this species (Length mm; width micrometers; weight micrograms) - Click:

Distribution:

Worldwide, Heterakis gallinarum is a nonmigrating parasite in the cecum of domestic and wild birds.

Economic Importance:

Although considered nonpathogenic, H. gallinarum is a vector of the protozoan, Histomonas meleagridis, the cause of histomoniasis (blackhead disease) in turkeys and other birds

The protozoan can be transmitted in the eggs of H. gallinarum or in earthworms containing the L2 of H, gallinarum

Life Cycle:

Life cycle is direct, intermediate hosts not required.

Eggs deposited in host fecets develop to the L2 in 14 days, depending on the temperature.
After egg ingestion by chickens or other birds in contaminated food or water, the L2 hatches and all three parasitic molts take place in the cecal lumen. There is no somatic migration.
Larvae in the mucosa return to the lumen and develop to adults along with those that remained in the lumen.
Earthworms that ingest eggs may act as transport hosts with L2 in their tissues. Infection of birds occurs when they eat paratenic earthworms..
The prepatent period is about 4 weeks

Ref Cruthers et al., 2020.

Ecophysiological Parameters:

For Ecophysiological Parameters for this species, click	If species level data are not available, click for genus level parameters

Damage:

Lethargy in heavy infections.

Infection by the protozoan parasite Histomonas meleagridis, the causal agent of Histomoniasis (blackhead disease) in poultry. Young birds are the most susceptible. The protozoan inhabitsa lumen of the cecum and tissues of the liver where it causes extansive necrosis.

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Management:

Sanitation, reducing exposure to feces in caged birds

Anthelminthics

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References:

Cruthers, L.R., Reinemeyer, C.R., Yazwinski, T.A., Marchiondo, A.A. 2020. Nematoda, Ascaridida. Chapter 2 in Marchiondo, Cruthers and Fourie (eds) Parasiticide Screening Vol 2. Academic Press

McMullin, P. 2004. A Pocket Guide to: Poultry Health and Disease 5M Enterprise, Sheffield, UK

Cruthers, L.R., Reinemeyer, C.R., Yazwinski, T.A., Marchiondo, A.A. 2020. Nematoda, Ascaridida. Chapter 2 in Marchiondo, Cruthers and Fourie (eds) Parasiticide Screening Vol 2. Academic Press