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| − | === Small strongyles (Cyathostomins) ===
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| − | ==== Morphology ====
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| − | '''Gross''':
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| − | *Small worms, <1.5cm long
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| − | *Small, shallow buccal capsule
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| − |
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| − | '''Microscopic''':
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| − | *Buccal capsule shape
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| − | *Double row of leaf crowns
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| − | *Teeth may be present
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| − |
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| − | ==== Life-cycle ====
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| − | *Infection by ingestion of L3
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| − | *Larvae invade mucosa of large intestine
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| − | *Larvae may develop to L4 without interruption
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| − | *Cyathostomin larvae can arrest at EL3 stage
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| − | *L4 emerge into gut lumen and mature to adult worms
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| − | *Prepatent period 8-12 weeks (depending on species)
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| − |
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| − | ==== Pathogenicity ====
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| − | '''General''':
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| − | *Adult and larval worms are plug feeders, restricting the damage to more superficial mucosa
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| − |
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| − | '''Cyathostominosis''':
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| − | *Initial infection (L3) → local inflammatory response
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| − | *Developing L4s can be seen as brown flecks in the mucosa
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| − | *They can be present in very large numbers (→ the so-called "pepper-pot lesion")
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| − | *Larval emergence throughout '''summer/autumn''' and plug-feeding of adults → major contributor to the "wormy" horse:
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| − | **Unthriftiness
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| − | **Poor coat
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| − | **Anaemia
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| − | **Diarrhoea)
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| − | *May be tens or hundreds of thousands of adults and millions of mucosal larvae present
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| − | *Emergence of massive numbers of previously arrested larvae in '''late winter/early spring''' → massive inflammatory infiltration → serious disease characterised by severe diarrhoea and/or weight loss (larval or Type 2 cyathostominosis)
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