- Haemonchus contortus (abomasum) - sheep
- 2cm long,barber's pole appearance when fresh
- Primarily a tropical/sub-tropical parasite, although may cause problems in the UK (was restricted to SE England but has spread north to Scotland due to warmer, wetter winters in recent years)
- Blood-sucking nematode (piercing "lancet" in buccal capsule of L4 and adult worms)