Ovine fascioliasis following reinfection.

Sheep were reinfected with matacercariae once. Half were treated with anthelmintic one week before reinfection. Compared with a primary infection, the reinfecting flukes in most seemed to migrate faster through the liver although in one treated sheep migration seemed to be longer and more destructive. Migrations extended into areas little affected by the primary infection thus producing more widespread fibrosis. Although a temporary retardation in fluke growth rate occurred, there was no reduction in the numbers of flukes recovered. Flukes killed by anthelmintic formed large granulomata.