The primary damage is reduced efficiency of feed utilization, but death has been observed in severe infections. Chickens of three to four months of age show resistance to infection. Specimens of this parasite are found occasionally in eggs. The worm apparently wanders from the intestine up the oviduct and is included in the egg contents as the egg in being formed. The life history of this parasite is simple and direct.
Females lay thick heavy-shelled eggs in the intestine that pass in the feces.
A small embryo develops in the egg but does not hatch immediately. The larvae in the egg reaches infective stage within two to three weeks. Embryonated eggs are very hardy and under laboratory conditions may live for two years. Under ordinary conditions, however, few probably live more than one year. Disinfectants and other cleaning agents do not kill eggs under farm conditions.