Nematodes (Roundworms) Flashcards
Structure of female nematodes
- mouth
- vulval flap
- anus
Structure of male nematodes
- spicules
- dorsal lobe
- copulatory bursa
Examples of ruminant nematodes- HOT
Haemonchus, Ostertagia, Trichstrongylus
Nematodes lifecycle (trichostrongylid nematodes)
- Eggs in faeces
- Developed eggs–> L1, L2
- Infective L3 stage ingested by sheep
- Exsheathment, development (L4 & L5) in sheep
- Male and female adults in sheep
Haemonchus aka
Barber’s pole
Ostertagia aka
small brown stomach wor
Trichostrongylus aka
black scour worm
Trichostrongylid nematodes: 3 general features of parasitism
- Ill thrift
- Scouring
- Anaemia
Trichostrongylid nematodes climate pasture L3 buildup
Summer rainfall pasture L3: Can’t tolerate winter cold and early summer “dry”
Winter rainfall pasture L3: Tolerate cold but not summer heat
Trichostrongylid nematodes: Host factors
- Host species:
- goats
Trichostrongylid nematodes: pathogen factors
Worm fecundity: affecting rapidly of pasture L3 buildup
Trichostrongylid nematodes: environmental factors
- Worm availability: pasture L3 levels, season/climate and worm species (die if its hot)
- Management:
- stocking rate, pasture rotatin
- nutrition/drought/other infections
- drench resistance
Increased epg occurs
post-lambing and lactation in time for ingestion of pasture L3 by susceptible lambs
Trichostrongylid nematodes: Diagnosis
- history of recent rain
- find worms (post mortem or pasture L3) and strongyle eggs
- measure PCV/mms
Haemonchosis causes:
- anaemia
- bottle jaw
- watery blood
- weight loss
