Onchocerca lupi, light microscopy. A) Cephalic extremity, male, lateral view. B) Posterior end and right spicule, dextral view. C) Region of vulva, lateral view; note oesophago-intestinal junction (arrowhead) and vulva (arrow). D1-3) Variations in the structure of the cuticle along the body of a female: at the level of appearance of first ridges and striae (D1), at the level close to the anterior body end, characterized by full formation of ridges and striae (D2), and from a mid-body fragment (D3); note cuticular ridges (arrowheads) and striae (arrows). E) Microfilaria in ovejector. Scale-bars in micrometers.