Early Ascaris suum migration in mice as a model for pigs.

A study was made of the early migratory pattern of Ascaris suum in mice. Mice were each inoculated orally with a single dose of 2,500 infective eggs and then killed at 2, 4, 6, 8, 10, and 12 hr postinoculation (PI). At necropsy, it was observed that the larvae had penetrated the mouse cecum and colon and had reached the liver by 4 hr PI. This migratory behavior closely mimics what is observed in the pig and suggests that the mouse may serve as an experimental model for intestinal immunity in the early phase of A. suum infection.