Haemonchus Contortus

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Haemonchus contortus

Identify adult teladorsagia circumcinta, trichostrongylous spp, cooperia spp, haemonchus spp, nematodirus battus +other nematodirus species. Identify trichostrongyle eggs and be able to differentiate from nematodirus spp eggs

Haemonchus contortus

Abomasum

Sheep , Goats, Cattle

Morphology

Barbers pole - F

White ovary

Red gut

Cervical papillae

V sturdy

Obvious

Asymmetrical dorsal lobe - M

Bursa

Between rays

V difficult to distinguish eggs from other trichostrongyle spp

Demonstrate a deep knowledge of the life cycle of harmonchus contortus

Typical trichostrongyle

PPP = 3 wks

Larvae develop in mucosa

Hypobiosis

Demonstrate understanding of the epidemiology of haemonchosis

Eggs don't overwinter

Ewe main source of pasture contamination (PPR)

Outbreaks late summer

Understand pathogenesis of disease associated with H. contortus infections in sheep

Serious threat to intensive sheep production

Pathogenesis

Blood feeders

Erosion of abomasum wall

Severe haemorrhage gastritis

Clinical signs

Anaemia - look at eyelids

Oedema

Bottle jaw

Weight loss

Diagnosis

Clinical signs

Esp anaemia

Season , late summer

Faecal EC

Control

Driven development of 2 new drugs

1st resistent to BZ

1st multidrug resistent

1st to be resistant to all older drugs

Monepantel !

Amino-acetonitrile

Resistance starting in Australia

Startect !

Derquantel + abamectin

Resistance starting in Australia

Vaccine !

Created due to resistance

Barbervax

Breaking up worms + giving lambs small dose gives some protection