The rate of recovery of intestinal morphology following anthelmintic treatment of parasitised sheep.

Sixteen sheep which had previously been infected with Ostertagia circumcincta were dosed with 4000 Trichostrongylus colubriformis larvae/day for four weeks, then given anthelmintic and killed at intervals thereafter. Histological examination of the small intestine showed that two to three weeks were required for restoration of a normal mucosal architecture.