Morphogenesis and distribution of Trichostrongylus retortaeformis in the intestine of the rabbit

The morphogenesis and the distribution along the digestive tract of Trichos trongylus retortaeformis (Zeder, 1800) (Nematoda) were studied in detail in one of its natural hosts, Oryctolagus cuniculus. Worm-free rabbits were ea ch infected with T. retortaeformis larvae and were killed at 12 h post-infe ction (HPI) and on each day from 1 to 15 days post-infection (DPI). The dis tribution of worm populations along the small intestine was assessed. At th e different dates of infection, more than 80% of the population was recover ed from the first third of the intestine with more than 50% occuring in the first 30 cm. For each date, morphological descriptions of the different st ages of the life cycle were also provided. In addition, adult worms collect ed from naturally infected rabbits from France were redescribed.