PPT - NCSU Veterinary Parasitology

VMP 930
Veterinary Parasitology
Nematodes
Strongylida
Strongylida Phylogenetic Tree pict
Order Strongylida
Bursate Worms
Trichostrongyle
Hookworm
(Ancylostomid)
Metastrongyle
Strongyle
Strongylida: Bursate Worms
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Males have copulatory
bursa to grasp female
during copulation
Strongylida: Bursate Worms
Most occur in Host’s GI Tract
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Trichostrongyles (most) -- Abomasum & Small Intestine
Strongyles -- Large Intestine, Colon
Hookworms -- Small Intestine
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Note exceptions
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Trichostrongyles (Dictyocaulus) -- Lungs
Metastrongyles -- Lungs
Strongylida: Bursate Worms
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Most pass strongyle-type
ova in feces.
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Note exceptions
Metastrongylus sp.
Dictyocaulus sp.
Trichostrongyles
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Small, long, thin worms
Vestigial Buccal cavity
Route of Infection – Ingestion of
Infective L3 on pasture
Most in Abomasum or S. Intestine
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Most have Strongyle-type ova
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Exception – Dictyocaulus in Lungs
Exception – Dictyocaulus -> larvae
Main Nematode Concern for
Ruminants (ex. Haemonchus, Ostertagia)
Strongyles
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Straight stout worms
Large Buccal Cavity with
teeth
Route of Infection –
Ingestion of Infective L3 on
pasture
In Colon & Cecum
Strongyle-type ova
Main Nematode Concern for
Horses (ex. Small & large
Strongyles)
Hookworms
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Straight stout worms
Large Buccal Cavity with teeth
Route of Infection
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(Ancylostomids)
Skin Penetration of Infective L3
Transmammary transmission
In Small Intestine
Strongyle-type ova
A Major Nematode Concern for
Pets (ex. Ancylostoma)
Metastrongyles
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Large, thin worms
No Buccal Cavity
Route of Infection – Ingestion of
Snail or Earthworm Intermediate
Host containing infective larvae
In Lungs
Ovoid Larvated eggs
A Nematode Concern for
Pastured Swine (ex. Metastrongylus)
Bursate Worms
Important Points
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What morphology is distinctly characteristic of the Strongylid
Nematodes?
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Compare & Contrast the 4 groups of nematodes that belong to the bursate
Nematode Group (Strongylid).
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Males have a Copulatory Bursa for grasping female during copulation.
Common name
General worm size & shape
Buccal Cavity
Host of Major concern
Location in host
Route of infection
Diagnostic stage
Of the Trichostrongyles, which worms are exceptions to the general
trichostrongyle characteristics. What are those exceptions?
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Dictyocaulus sp.
Found in the lungs
Larvae in the feces.
The Following is
Review ONLY
(Deadly Dew Drop)

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