Difference between revisions of "Category:Horse Nematodes"

Revision as of 10:33, 26 April 2010

Gastrointestinal Nematodes

Introduction

Parascaris equorum - Joaquim Castellà Veterinary Parasitology Universitat Autònoma de Barcelona

Strongylus - Joaquim Castellà Veterinary Parasitology Universitat Autònoma de Barcelona

Many nematode species occur in the equine gastrointestinal tract, although not all are of equal importance:

Stomach

Small Intestine

Large Intestine

Habronema (Draschia)

Trichostrongylus axei

Parascaris

Strongyloides

Strongylus species

Cyathostomins

Triodontophorus species

Oxyuris equi

Strongyles (Red worms)

The strongyles that occur in the horse can be divided on the basis of size into two groups

Large strongyles
- Strongylus species (3 species; used to be widespread prior to the introduction of worm control programmes; now uncommon)
- Triodontophorus species (common)
Small strongyles
- Also known as Cyathostomins (preferred term), cyathostomes, trichonemes or small redworms
- Cyathostomins (widespread, including 4 genera and over 40 species of worms)

Large strongyles

Morphology

Gross

Stout worms, 1.5-5cm long
Large buccal capsule
Bursa visible to the naked eye (male worms only)

Microscopic (buccal capsule)

Double row of leaf crowns
Teeth (0, 2, 3 or more)
Dorsal gutter (channel for secretions)

Life-cycle

Infection with all three Strongylus species and Triodontophorus is by ingestion of infective stage larvae (L3) at grazing. Larvae pass down the intestinal tract and penetrate the intestinal mucosa at which point there are important species differences in life-cycle.

Pathogenicity

Adult Worms:

Plug feeders
Strongylus species:
- Large buccal capsule
- Penetrate right down to the muscularis layer and blood vessels
- Leaves small circular bleeding ulcers → anaemia if present in large numbers
Triodontophorus:
- Smaller buccal capsule
- More superficial damage
- May feed in "herds", leaving large ulcers, several centimetres across
Ulcers heal and leave scars

Pages in category "Horse Nematodes"

The following 16 pages are in this category, out of 16 total.

C

Cyathostomins

D

Dictyocaulus arnfieldi

H

L

Large Strongyles

O

P

S

T

@@ Line 43: / Line 43: @@
 **Also known as Cyathostomins (preferred term), cyathostomes, trichonemes or small redworms
 **Cyathostomins (widespread, including 4 genera and over 40 species of worms)
+=== Large strongyles ===
+==== Morphology ====
+'''Gross'''
+*Stout worms, 1.5-5cm long
+*Large buccal capsule
+*Bursa visible to the naked eye (male worms only)
+'''Microscopic''' (buccal capsule)
+*Double row of leaf crowns
+*Teeth (0, 2, 3 or more)
+*Dorsal gutter (channel for secretions)
+==== Life-cycle ====
+Infection with all three ''Strongylus'' species and ''Triodontophorus'' is by ingestion of infective stage larvae (L3) at grazing. Larvae pass down the intestinal tract and penetrate the intestinal mucosa at which point there are important species differences in life-cycle.
+==== Pathogenicity ====
+'''Adult Worms''':
+*Plug feeders
+*''Strongylus'' species:
+**Large buccal capsule
+**Penetrate right down to the muscularis layer and blood vessels
+**Leaves small circular bleeding ulcers → anaemia if present in large numbers
+*''Triodontophorus'':
+**Smaller buccal capsule
+**More superficial damage
+**May feed in "herds", leaving large ulcers, several centimetres across
+*Ulcers heal and leave scars
 [[Category:Nematodes]][[Category:Horse]]