Scanning electron microscopy of the jejunal and ileal mucosa of rabbits infected with Trichostrongylus colubriformis.

The jejunum and ileum of rabbits infected by immature stages of Trichostrongylus colubriformis were examined with the scanning electron microscope. In the heavily parasitised jejunum, the normally leaf-shaped villi often showed abnormal shapes. Surface epithelial cells became rounded and dome-shaped, and apical microvilli appeared irregular. In the ileum, where the density of worms was much lower than in the jejunum, the main difference observed was the irregular arrangement of the microvilli. The changes observed in rabbits parasitised with immature T colubriformis were compared with previous scanning electron microscope observations of lambs and rats infected with adult intestinal nematodes and the origin and functional significance of the lesions were discussed.