Changes

== Life-Cycle ==

== Life-Cycle ==

The adults live unattached in the small intestine.  In heavy infections, they may form large balls, which can cause intestinal obstruction.  Under optimal conditions L2 can develop in 14 days.  The host ingests the embryonated egg.  L2 larvae then pass through the intestinal wall, and transform into L3.  They then migrate to the liver via the hepatic portal vein, where they stay for around a week.  They then enter the vena cava and travel to the pulmonary alveoli, where they transform to L4.

The adults live unattached in the small intestine.  In heavy infections, they may form large balls, which can cause intestinal obstruction.  Under optimal conditions L2 can develop in 14 days.  The host ingests the embryonated egg.  L2 larvae then pass through the intestinal wall, and transform into L3.  The larvae then migrate to the liver via the hepatic portal vein, where they stay for around a week.  They enter the vena cava and travel to the pulmonary alveoli, where they transform to L4.

They then travel up bronchi to the trachea and are coughed up and swallowed.  They then return to the stomach and small intestine, where they mature into adults.

The larvae travel up bronchi to the trachea and are coughed up and swallowed.  Finally they return to the stomach and small intestine, where they mature into adults.

The prepatent period of ''P. equorum'' is 10-16 weeks.

The prepatent period of ''P. equorum'' is 10-16 weeks.