Trichinella spiralis • Synonym: Trichina spiralis • Common name: Muscle worm • Predilection site: Small intestine, muscle • Parasite class: Nematoda • Superfamily: Trichuroidea • Description, gross: Because of their short lifespan, the adult worms are rarely found in natural infections. The male is about 1.5 mm and the female 3.5–4.0 mm long. • Hosts: Pig, rat, man, and most mammals Coiled infective larvae of Trichinella spiralis in striated muscle (right). Macracanthorhynchus hirudinaceus • • • • Common name: Thorny-headed worm Predilection site: Duodenum and proximal small intestine Parasite class: Acanthocephala Family: Oligacanthorhynchidae • Description, gross: Adults resemble Ascaris suum, but taper posteriorly.The males are up to 10 cm and the females around 60 cm in length and slightly pinkish in colour when fresh • Definitive hosts: Pig, wild boar, occasionally dog, wild carnivores and man • Intermediate hosts: Various dung beetles and water beetles Head of Macracanthorhynchus hirudinaceus showing the retractible proboscis (right). LIFE CYCLE Oesophagostomum • Six species of Oesophagostomum have been described from pigs. • Hosts: Pig • Oesophagostomum dentatum • • • • Common name: Nodular worm Predilection site: Large intestine Parasite class: Nematoda Superfamily: Strongyloidea • Other species include: • Hosts: Pig • Geographical distribution: Europe • Oesophagostomum georgianum • Oesophagostomum quadrispinulatum • Common name: Nodular worm • Oesophagostomum brevicaudum • Predilection site: Large intestine • Oesophagostomum longicaudatum • Parasite class: Nematoda • Superfamily: Strongyloidea • Geographical distribution: North America • Oesophagostomum granatensis • Common name: Nodular worm • Predilection site: Large intestine • Parasite class: Nematoda • Superfamily: Strongyloidea Trichuris suis • Synonym: Trichocephalus suis • Common name: Whipworms • Predilection site: Large intestine • Parasite class: Nematoda • Superfamily: Trichuroidea • Description, gross: The adults are whitish and about 3–5 cm long with a thick broad posterior end tapering rapidly to a long filamentous anterior end that is characteristically embedded in the mucosa. • Hosts: Pig, wild boar • Trichuris suis on the surface of the large intestine (right) Life cycle:
