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{{Taxobox
{{Taxobox
|name =''Dictyocaulus filaria
|name =''Dictyocaulus filaria
|species ='''''D. filaria'''''
|species ='''''D. filaria'''''
}}
}}
Also known as: '''''Sheep lungworm
==Hosts==
==Hosts==
The life cycle of ''D. filaria'' is very similar to that of ''[[Dictyocaulus viviparus]]''. It is a direct life cycle, and the females are ovo-viviparous. The females lays eggs which contain mature larvae. The eggs hatch quickly, and the L3 larvae are ingested by the host. The larvae then travel to the mesenteric lymph nodes where they moult. They then travel to the lungs via the blood or lymphatic system.
The life cycle of ''D. filaria'' is very similar to that of ''[[Dictyocaulus viviparus]]''. It is a direct life cycle, and the females are ovo-viviparous. The females lays eggs which contain mature larvae. The eggs hatch quickly, and the L3 larvae are ingested by the host. The larvae then travel to the mesenteric lymph nodes where they moult. They then travel to the lungs via the blood or lymphatic system.
The final transformations occur in the bronchioles, and the adults fully mature in the bronchi, causing [[Bronchi and Bronchioles Inflammatory - Pathology#Infectious causes of bronchitis or bronchiolitis|bronchitis]].
The final transformations occur in the bronchioles, and the adults fully mature in the bronchi, causing [[Bronchitis#Infectious causes of bronchitis or bronchiolitis|bronchitis]].
L1 larvae are then coughed and swallowed. The larvae enter the intestinal tract, and are passed out in the faeces.
L1 larvae are then coughed and swallowed. The larvae enter the intestinal tract, and are passed out in the faeces.
The prepatent period of ''D. filaria'' is 4-5 weeks.
The prepatent period of ''D. filaria'' is 4-5 weeks.
=== Pathogenesis ===
*Caused by '''''[[Dictyocaulus filaria]]'''''
**Similar to [[Dictyocaulus viviparus|''D. viviparus'']] in cattle
**Lesions tend to be less widespread because worm numbers are generally low
=== Diagnosis ===
*Grazing history
*Clinical signs
*Faecal examination (larval identification possible by examining head, e.g. ''Dictyocaulus filaria'' (knob) or tail, e.g. ''Muellerius'' (single spine), ''Protostrongylus'' (wavy, no spine) → prognosis)
=== Control ===
*'''''Dictyocaulus filaria''''':
**Difficult because outbreaks are unpredictable
**PGE control measures are normally sufficient to prevent outbreaks of disease
**Where these occur, remove and treat affected stock, replace with older immune sheep if necessary
**A commercial vaccine was available in the Middle East, though its use (were it still available) would be uneconomic in the UK
{{Learning
|flashcards = [[Small_Ruminant_Nematodes_Flashcards|Small Ruminant Nematodes Flashcards]]
|literature search = [http://www.cabdirect.org/search.html?q=title%3A%28%22Dictyocaulus+filaria%22%29 ''Dictyocaulus filaria'' publications]
}}
==References==
==References==
Taylor, M.A, Coop, R.L., Wall,R.L. (2007) '''Veterinary Parasitology''' ''Blackwell Publishing''
Taylor, M.A, Coop, R.L., Wall,R.L. (2007) '''Veterinary Parasitology''' ''Blackwell Publishing''
[[Category:Trichostrongyloidea]][[Category:Sheep_Nematodes]]
[[Category:Dictyocaulus]][[Category:Sheep_Nematodes]]
[[Category:Respiratory Parasitic Infections]]
[[Category:Respiratory Parasitic Infections]]
[[Category:Goat_Nematodes]]
[[Category:Goat_Nematodes]]