Difference between revisions of "Filaroides osleri"

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=== '''''FILAROIDES (= Oslerus) OSLERI''''' ===
Also known as: '''''Dog lungworm — Oslerus osleri'''''
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*''F. osleri'' is atypical of the Metastrongyloidea in almost every way.
{{Taxobox
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*Adults (approximately 1cm) are found in dogs clustered in fibrous nodules (few mm - 2cm) on tracheal wall (near bifurcation of trachea).
|name              = ''Filaroides osleri
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*This means that small numbers of L1 are found in the sputum, and can either be passed to the skin during grooming, or can be passed in the faeces (dead-end for life-cycle).
|kingdom            =Animalia
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*Transmission from bitch to pups occurs during grooming via transfer of sputum.
|phylum            =[[Nematodes|Nematoda]]
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*Horizontal transmission rarely, if ever, happens.
|class              =Secernentea
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*Infection is usually asymptomatic, but if symptoms are present, there is a chronic, dry, debilitating cough - performance of greyhounds may be affected.
|sub-class          =
 
|order              =Strongylida
 
|super-family      =[[:Category:Metastrongyloidea|Metastrongyloidea]]
 
|family            =Filaroididae
 
|sub-family        =
 
|genus              =Filaroides
 
|species            = ''Filaroides osleri
 
}}
 
  
==Introduction==
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=== ''Filaroides'' Infections ===
''Filaroides osleri'' is a [[:Category:Metastrongyloidea|metastrongyloid]] nematode that lives in '''granulomatous nodules''' located on the mucosal surface of the '''distal trachea, tracheal bifurcation and first division bronchi''' in '''dogs''' and wild canid species.
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*''F. osleri'' is usually associated with particular boarding kennels.
 +
*Diagnosis and treatment are difficult.
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*The Baermann apparatus is used to recover L1 from faeces.
 +
*Larvae are, however, few in number and have sluggish movements.
 +
*They may, therefore, be very difficult to demonstrate in faeces or sputum.
 +
*Endoscopy (to visualise the tracheal nodules) is often required to confirm diagnosis.
  
==Identification==
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Fenbendazole is licensed for the treatment.
The adults are pale, thin [[:Category:Nematodes|nematodes]]. The female is larger than the male, at around 9-15mm in length.
 
 
 
==Life Cycle==
 
This is a direct life cycle, so forms the exception in the superfamily [[:Category:Metastrongyloidea|'''Metastrongyloidea''']]. The females are ovo-viviparous. The eggs are laid, and hatch within the trachea. They then transform into the larvae, which are coughed up and swallowed. They enter the intestine, and are passed out in the feces.
 
 
 
The bitch may transfer the larvae to the pup '''during grooming''', or infection may come about via '''ingestion of the larvae'''. The larvae '''mature and travel to the lungs'''. 
 
 
 
The prepatent period is '''10-18 weeks'''.
 
 
 
==Clinical Signs==
 
The primary clinical sign is a '''chronic cough'''. Progressively enlarging granulomatous nodules may obstruct airflow and lead to signs such as '''exercise intolerance, dyspnoea or even death'''.
 
 
 
'''Spontaneous pneumothorax''' can occur extremely rarely.
 
 
 
==Diagnosis==
 
The tracheobronchial nodules may occasionally be detected '''radiographically''' as large, space-occupying masses protruding into the tracheal lumen near the bifurcation.
 
 
 
'''Bronchoscopic visualisation''' is the best way to detect the mucosal nodules.
 
 
 
'''Bronchial washings''' may then reveal larvated ova and larvae with a kinked tail.
 
 
 
'''Feces''' can be examined for larvae, but this is less rewarding.
 
 
 
'''Zinc-sulphate centrifugation/flotation''' is preferred to the Baermann method as the larvae are lethargic and do not migrate out of the fecal mass.
 
 
 
==Treatment==
 
Endoscopic examination and '''removal of the nodules''' is essential for a successful outcome.
 
 
 
A good clinical response may be seen using extended courses of '''ivermectin, fenbendazole, albendazole and levamisole'''. This does not always clear the nodules on follow-up bronchoscopy.
 
 
 
In a '''breeding colony''', bitches should be '''treated before whelping''', and pups should be separated from older infected dogs to prevent horizontal transmission by ingestion of infected feces. In infected dogs, good hygiene is essential, and pups could be '''hand-raised''' or foster-reared on uninfected bitches.
 
 
 
{{Learning
 
|literature search = [http://www.cabdirect.org/search.html?rowId=1&options1=AND&q1=%22Filaroides+osleri%22&occuring1=title&rowId=2&options2=OR&q2=%22Osterus+osleri%22&occuring2=title&rowId=3&options3=AND&q3=&occuring3=freetext&x=51&y=13&publishedstart=yyyy&publishedend=yyyy&calendarInput=yyyy-mm-dd&la=any&it=any&show=all ''Filaroides osleri'' publications]
 
 
 
|Vetstream = [https://www.vetstream.com/canis/search?s=nematode Nematodes]
 
}}
 
 
 
==References==
 
Taylor, M.A, Coop, R.L., Wall,R.L. (2007) '''Veterinary Parasitology''' ''Blackwell Publishing''
 
 
 
King, L. (2004) '''Textbook of respiratory disease in dogs and cats''' ''Elsevier Health Sciences''
 
 
 
Pinckney, R. D. (2000) '''Canine Filaroides infection in Companion and Exotic Animal Parasitology''' ''IVIS publication''
 
 
 
 
 
 
 
{{review}}
 
 
 
{{OpenPages}}
 
  
 
[[Category:Metastrongyloidea]][[Category:Dog_Nematodes]]
 
[[Category:Metastrongyloidea]][[Category:Dog_Nematodes]]
[[Category:Expert_Review - Small Animal]]
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[[Category:To_Do_-_Parasites]]
[[Category:Respiratory Parasitic Infections]]
 
[[Category:Respiratory Diseases - Dog]]
 

Revision as of 21:55, 25 June 2010

FILAROIDES (= Oslerus) OSLERI

  • F. osleri is atypical of the Metastrongyloidea in almost every way.
  • Adults (approximately 1cm) are found in dogs clustered in fibrous nodules (few mm - 2cm) on tracheal wall (near bifurcation of trachea).
  • This means that small numbers of L1 are found in the sputum, and can either be passed to the skin during grooming, or can be passed in the faeces (dead-end for life-cycle).
  • Transmission from bitch to pups occurs during grooming via transfer of sputum.
  • Horizontal transmission rarely, if ever, happens.
  • Infection is usually asymptomatic, but if symptoms are present, there is a chronic, dry, debilitating cough - performance of greyhounds may be affected.

Filaroides Infections

  • F. osleri is usually associated with particular boarding kennels.
  • Diagnosis and treatment are difficult.
  • The Baermann apparatus is used to recover L1 from faeces.
  • Larvae are, however, few in number and have sluggish movements.
  • They may, therefore, be very difficult to demonstrate in faeces or sputum.
  • Endoscopy (to visualise the tracheal nodules) is often required to confirm diagnosis.

Fenbendazole is licensed for the treatment.