Nematodes

Nematodes

1. Ensheathed L3 ingested from pasture

   • L3 exsheathes in the rumen
     • L3 migrates to the abomasum and moults to in the stomach glands L4
       • Adult emerges from glands and feeds on stomach lining
         • Egg containing L1 shed in faeces
           • Egg hatches and L2 feeds on faeces
             • Teladorsagia circumcincta

2. Aleurostrongylus abstrasus

   • L1 larvae ingested by slug or snail
     • L1 develops to L3 in slug
       • Slug eaten by bird
       • Eaten by cat
         • Bird infected
         • L3 larvae migrate from the gut to the lungs where they mature
           • Eggs in sputum coughed up and swallowed, where L1 is shed in faeces

3. Toxocara canis

   • L3 develops in egg and is infective after 2-4 weeks
     • Ingested eggs hatch in h=the gut and undergo hepatic-tracheal migration to reach the small intestine
       • L3 can be passed from mother to pup in utero or in milk
         • Eggs shed in faeces

4. Toxocara cati

   • Infection via ingestion of L3 in egg or from mouse paratenic host
     • L3 undergo hepatic-tracheal migration to return to the small intestine
       • Infection passed to kittens via milk
         • Eggs shed in faeces

5. Strongylus vulgaris

   • Infection via ingestion of L3 in egg or mouse paratenic host
     • L3 migrate through the mesenteric arteries and mature in a thrombus then return to the large intestine
       • Eggs released into faeces

6. Uncinaria stenocephala

   • Infection via ingestion of ensheathed L3 which matures in the small intestine
     • Percutaneous infection from L3 can occur, resulting in migration through tissue to thel lungs, get swallowed and reach small intestine
       • Adults feed on blood in the SI
         • Eggs released in faeces

7. Parascaris equorum

   • Ingestion of L3 in egg resulting in hepatic-tracheal migration
     • Adults return to small intestine
       • Eggs released in faeces

8. Trichuris Vulpis

   • Infection via ingestion of L1 in egg
     • Adult in large intestine
       • Eggs shed in faeces