Chicken Ascarid
Rev 10/25/2025
Subclass: Chromadoria
Order: Rhabditida
Superfamily: Ascaridoidea
Family: Ascarididae
Ascaridia galli (Schrank, 1878) Freeborn, 1923
Synonym:
Males:
Females:
Ref: Cruthers et al., 2020
Worldwide, Ascaridia galli is a nonmigrating ascarid in the small intestine of domestic and wild birds.
Ascaridia galli is considered the most common intestinal helminth in organic layer flocks in Austria, Belgium, Denmark, Germany, Italy, The Netherlands, Sweden, and the United Kingdom.
Infections with A. galli have increased in European countries due to the ban on battery cages.
Intestinal parasites
Life cycle is direct, intermediate hosts not required.
Eggs develop to the L2 in 9-21 days, depending on the temperature.
After egg ingestion by chickens in contaminated food or water, the L2 hatches in the proventriculus or small intestine. Some larvae penetrate the intestinal mucosa or remain in the 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.
The prepatent period is 5-6 weeks
Ref Cruthers et al., 2020.
Ecophysiological Parameters:
Symptoms of heavy infection in caged biirds include anorexia, diarrhea, stunted growth, listlessness, changes in behavior, and enteritis. Heavy infections can cause a partial or total obstruction of the gastrointestinal tract.
Laying hens may produce soft eggs with thin and misshapened shells.
Clinical signs are more common in young chickens less than three months old, as older chicken develop some resistance to infection. Infection may be diagnosed on clinical signs and fecal examination (McMullin, 2004).
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