Nematodirus spp Flashcards
Where in the GI tract is nematodirus spp found?
Small intestine
What animals do nematodirus spp affect? What about N.battus?
Cattle and sheep
N. battus = lambs only
In what climate is nematodirus found?
Cold
Describe the morphology of nematodirus spp
2cm (LONG) Groups of worms tangled together Cervical vesicles Males have long spicules Females have large brown eggs in utero
What is the life cycle of Nematodirus?
Unembryonated eggs shed in faeces L3 develops in the egg and hatches L3 (infective stage) is ingested L4 burrows into SI mucosa and develops to L5 L5 emerges from SI mucosa
What is the prepatent period of Nematodirus?
15 days
How does the nematodirus larvae cause damage?
L4 burrowing into SI mucosa and L5 emerging
What does nematodirus cause?
Catarrhal enteritis
Villous atrophy
What are the clinical signs of an infection by Nematodirus battus
Sudden explosive acute watery D+ Abdominal pain Dehydration and thirst Inappetance Weight loss
At what age are lambs infected by Nematodirus battus? Why is this?
4-12 weeks
Lambs are old enough to graze but before immunity develops
What are the hatching requirements of an N. battus egg?
Prolonged chilled period
Mean temperature of 10 degrees
When does N. battus infection occur?
Huge emergence on pasture in Spring
Now also Autumn (global warming)
What is infestation by nematodirus spp called?
Nematodiriasis
What are the factors needed for nematodiariasis to occur?
Hatching must collide with susceptible lambs (4-12wks)
N. battus is passed from lamb to lamb. Why are ewes unaffected by N. battus?
Strong immune system
