Difference between revisions of "Dictyocaulus arnfieldi"

Revision as of 10:52, 21 May 2010

Lungworm

DICTYOCAULUS ARNFIELDI

Dictyocaulus arnfieldi from horse faeces - Joaquim Castellà Veterinary Parasitology Universitat Autònoma de Barcelona

General

Lungworm of equidae; adult worms found in smaller bronchi. Frequently incriminated as the cause of a chronic cough.

Morphology and Life-Cycle

Similar to lungworm in cattle, except:
- embryonated eggs (80-100µm) passed in fresh faeces; and
- prepatent period = 12weeks.

Epidemiology

Main source of infection = donkeys (remain infected for years) - contaminate horse pasture.
Infection can cycle in horses.

	Horses	Donkeys
Prevalence	10-20%	75%
Adult worms	Few	Many
Eggs in faeces	Often zero	Many
Period of patency	<8months	5+ years
Clinical signs	Sometimes	Rarely

NOTE: Clinical signs - chronic cough at rest or during exercise, single animal or group of horses, autumn or early winter.

Dictyocaulus arnfieldi causes cough in horses

Pathogenicity

Raised areas of over-inflated pulmonary tissue (several cms in diameter) surrounding small bronchus containing worms and mucopurulent exudate.
Hyperplastic bronchial epithelium.
Peribronchial "cuffing".

Diagnosis

Clinical signs.
Grazing history (donkey contact or shared grazing).
Faecal examination (only detects patent infections = small proportion of lungworm infections in horses):
- process sample immediately = McMaster method, embryonated eggs
- process sample later = Baerman technique, larvae with tail spine.
Tracheobronchial washings (large eosinophils).
Response to anthelmintic treatment (e.g. resolution of clinical signs = retrospective diagnosis).

Control

Do not keep horses on pastures grazed by donkeys (potential carriers).
Treat donkeys with appropriate anthelmintic in spring if grazed with horses.

@@ Line 1: / Line 1: @@
-{{OpenPagesTop}}
+== Lungworm ==
-{{Taxobox
+=== ''DICTYOCAULUS ARNFIELDI'' ===
-|name               =''Dictyocaulus arnfieldi
-|kingdom            =
-|phylum             =
-|class              =[[:Category:Nematodes|Nematoda]]
-|sub-class          =
-|order              =
-|super-family       =[[Trichostrongyloidea]]
-|family             =
-|sub-family         =
-|genus              =Dictyocaulus
-|species            ='''''D. arnfieldi'''''
-}}
 [[Image:Dictyocaulus arnfieldi.jpg|thumb|right|150px|''Dictyocaulus arnfieldi'' from horse faeces - Joaquim Castellà Veterinary Parasitology Universitat Autònoma de Barcelona]]
-Also known as: '''''Equine lungworm
+==== General ====
+*Lungworm of equidae; adult worms found in smaller bronchi. Frequently incriminated as the cause of a chronic cough.
-==Hosts==
+==== Morphology and Life-Cycle ====
-Donkeys, and occasionally horses.
+*Similar to lungworm in cattle, except:
+**embryonated eggs (80-100µm) passed in fresh faeces; and
+**prepatent period = 12weeks.
-==Identification==
+==== Epidemiology ====
-''D. arnfieldi'' are of the superfamily [[Trichostrongyloidea]].  Adults are slender, thread-like and white.  Females are larger than males at around 6.5cm in length.  The males have a small non-lobulated bursa.
+*Main source of infection = donkeys (remain infected for years) - contaminate horse pasture.
+*Infection can cycle in horses.
-The embryonated eggs are 80-100µm in length.
-==Life Cycle==
+{| style="width:75%; height:200px" border="1"
-The lifecycle is not greatly known, but it is currently thought to be similar to that of ''[[Dictyocaulus viviparus]]''.
-The prepatent period is 2-3 months.
+!
+!'''Horses'''
+!'''[[Lungworm - Donkey|Donkeys]]'''
-{{Learning
+|-
-|flashcards = [[Horse_Nematode_Flashcards|Horse Nematode Flashcards]]
+|'''Prevalence'''
-|literature search =[http://www.cabdirect.org/search.html?rowId=1&options1=AND&q1=%22Dictyocaulus+arnfieldi%22&occuring1=title&rowId=2&options2=AND&q2=&occuring2=freetext&rowId=3&options3=AND&q3=&occuring3=freetext&x=42&y=10&publishedstart=yyyy&publishedend=yyyy&calendarInput=yyyy-mm-dd&la=any&it=any&show=all ''Dictyocaulus arnfieldi'' publications]
+|10-20%
-|Vetstream = [https://www.vetstream.com/canis/search?s=nematode Nematodes]
+|75%
-}}
+|-
+|'''Adult worms'''
+|Few
+|Many
+|-
+|'''Eggs in faeces'''
+|Often zero
+|Many
+|-
+|'''Period of patency'''
+|<8months
+|5+ years
+|-
+|'''Clinical signs'''
+|Sometimes
+|Rarely
+|}
-{{review}}
+'''NOTE''': Clinical signs - chronic cough at rest or during exercise, single animal or group of horses, autumn or early winter.
-{{OpenPages}}
+*''Dictyocaulus arnfieldi'' causes [[Respiratory Parasitic Infections - Pathology#Dictyocaulus arnfieldi|cough in horses]]
+==== Pathogenicity ====
+*Raised areas of over-inflated pulmonary tissue (several cms in diameter) surrounding small bronchus containing worms and mucopurulent exudate.
+*Hyperplastic bronchial epithelium.
+*Peribronchial "cuffing".
-[[Category:Dictyocaulus]][[Category:Horse_Nematodes]]
+==== Diagnosis ====
+*Clinical signs.
+*Grazing history (donkey contact or shared grazing).
+*Faecal examination (only detects patent infections = small proportion of lungworm infections in horses):
+**process sample immediately = McMaster method, embryonated eggs
+**process sample later = Baerman technique, larvae with tail spine.
+*Tracheobronchial washings (large eosinophils).
+*Response to anthelmintic treatment (e.g. resolution of clinical signs = retrospective diagnosis).
-[[Category:Expert_Review]]
+==== Control ====
-[[Category:Respiratory Parasitic Infections]]
+*Do not keep horses on pastures grazed by donkeys (potential carriers).
+*Treat donkeys with appropriate anthelmintic in spring if grazed with horses.
+[[Category:Trichostrongyloidea]][[Category:Horse_Nematodes]]