Difference between revisions of "Ostertagia"

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{{Taxobox
 
{{Taxobox
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|name =Ostertagia spp.              
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|name               =Ostertagia spp.
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|kingdom =Animalia            
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|kingdom           =Animalia
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|sub-kingdom =        
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|phylum =Nematoda            
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|phylum             =Nematoda
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|order =              
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|order             =
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|sub-order =          
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|sub-order         =
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|super-family =[[Trichostrongyloidea]]       
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|super-family       =Trichostrongyloidea
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|family =            
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|family             =
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|genus =Ostertagia              
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|genus             =Ostertagia
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|species =''O. osteragi''            
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|species           =''O. osteragi''
 
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==Overview==
 
==Overview==
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''Ostertagia spp.'' are small bursate nematodes that parasitise the gastrointestinal tract of mammals and birds. These species are responsible for mortality and morbidity in a number of ruminants especially ''O. ostertagi'' which is widely considered the most important parasite of cattle.
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''Ostertagia spp.'' are small bursate nematodes that parasitse the gastrointestinal tract of mammals and birds. These species are responsible for mortality and morbidity in a number of ruminants especially ''O. ostertagi'' which is widely considered the most important parasite of cattle.
  
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==''Ostertagia ostertagi''==
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===''Ostertagia ostertagi''===
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{| cellpadding="5" cellspacing="0" border="1"  
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{| cellpadding="5" cellspacing="0" border="1"  
 
| Also known as:
 
| Also known as:
 
| ''O. ostertagi''
 
| ''O. ostertagi''
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''O. lyrata''<br />
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''O. lyrata''
 
''Skrjabinagia lyrata''
 
''Skrjabinagia lyrata''
 
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|-
 
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These worms are found throughout the world, and are considered the most important parasite of cattle, especially in temperate regions. The primary host is cattle but they can also be found in deer and goats occasionally. 
 
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====Identification====
 
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The adult ''O. ostertagi'' worms are thread like, reddish worms with short buccal cavities. The males can measure 6-8mm, the females 8-9mm. There are several [[Nematode Structure and Function|cuticle morphologies]] used to identify these worms at a microscopic level. The head of both sexes is square and the adults have 16 gut cells. The anterior cuticle has transverse striations, where as the rest of the body has longitudinal ridges. Male spicules are brown and curved, they split at the posterior to form 3 hooks. In the females the tail tapers to a fine end with a rounded tip and the vulva is covered by a cuticular flap.
 
  
 
==== Life-Cycle ====
 
==== Life-Cycle ====
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''O. ostertagi'' have a direct, non-migratory life-cycle. Calves are infected following ingestion of L3 that under moist conditions migrate from the faeces to pasture. The larvae are swallowed, pass through the forestomachs and develop in the abomasal gastric glands to the L4 stage, emerging as adult (L5) worms after nearly 3 weeks. Adult female worms then produce strongyle eggs which are passed out with the faeces. The prepatent period is 16 - 23 days (5-6 months if arrested at early (E)L4 stage).
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A direct, non-migratory life-cycle. Calves are infected following ingestion of L3 with grass. The larvae are swallowed, pass through the forestomachs and develop in the abomasal gastric glands to the L4 stage, emerging as adult (L5) worms (brown, cotton-like, 1cm long) after nearly 3 weeks. Adult female worms then produce strongyle eggs which are passed out with the faeces. The prepatent period is 3 weeks (5-6 months if arrested at EL4 stage).
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==== Epidemiology and Pathogenesis====
 
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The epidemiology of ''O.ostertagi'' is complex due to the hardyness of the eggs in the environment and the ability of larvae to hyperbiose. Clinical infections of this worm are termed [[Ostertagiosis - Cattle|Ostertagiosis]], the clinical page explains the pathophysiology and the epidemiology of the disease.
 
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==''Teladorsagia (Ostertagia) circumcincta''==
 
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{| cellpadding="5" cellspacing="0" border="1" 
 
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| Also known as:
 
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| Sheep brown stomach worm
 
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This is a major abomasal worm of sheep and goats, that is found worldwide. This worm is of great economical importance in both causing mortality and decreased weight gain in production animals. Resistance to all types of anthelmintics is common amongst the wild species making control and treatment difficult.
 
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====Identification====
 
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Adult worms have a common ostertagia appearance, slender, reddish in colour with a short buccal capsule. The worms are very short, males 6-8mm, female 8-10mm. Microscopically male ''T. circumcincta'' worms have well developed lateral lobes of the bursa and long thin spicules. In females a vulval flap is present, the tail is transversely striated and tapers to a fine rounded tip. 
 
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There are two morph species of ''T. circumcincta''; ''T. davtiani'' and ''Ostertagia trifurcata'', both of which have slightly different microscopic appearances to the ''T. circumcincta''. In males the bursa is longer in both species and the spicules, shorter and broader. 
 
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====Life Cycle====
 
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The life cycle is the same as that of ''O. ostertagi'' described above.
 
  
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====Epidemiology and Pathogenesis====
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Causes [[Ostertagiosis - Cattle|Ostertagiosis]]
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''T. circumcincta'' and ''O. trifurcata'' are responsible for clinical disease predominantly in lambs. The Pathophysiology of the disease is analogous to [[Ostertagiasis|ostertagiasis]] in cattle, though the type II form of disease is not seen as often in sheep and goats. The main feature in the epidemiology is the occurrence of a peri-parturient rise (PPR) in the number of larvae present as is seen in the disease in cattle.
 
  
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[[Category:Trichostrongyloidea]][[Category:Cattle Nematodes]]
  
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[[Category:To_Do_-_NickJ]]
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[[Category:Trichostrongyloidea]]
 
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[[Category:Cattle Nematodes]]
 
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[[Category:Sheep Nematodes]]
 
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[[Category:Goat Nematodes]]
 
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[[Category:To Do - Major]]
 
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[[Category:To_Do_-_Parasites]]
 

Revision as of 17:32, 5 August 2010


 This article is still under construction.



Ostertagia spp.
Kingdom Animalia
Phylum Nematoda
Super-family Trichostrongyloidea
Genus Ostertagia
Species O. osteragi


Overview

Ostertagia spp. are small bursate nematodes that parasitse the gastrointestinal tract of mammals and birds. These species are responsible for mortality and morbidity in a number of ruminants especially O. ostertagi which is widely considered the most important parasite of cattle.

Ostertagia ostertagi

Also known as: O. ostertagi

O. lyrata Skrjabinagia lyrata

Life-Cycle

A direct, non-migratory life-cycle. Calves are infected following ingestion of L3 with grass. The larvae are swallowed, pass through the forestomachs and develop in the abomasal gastric glands to the L4 stage, emerging as adult (L5) worms (brown, cotton-like, 1cm long) after nearly 3 weeks. Adult female worms then produce strongyle eggs which are passed out with the faeces. The prepatent period is 3 weeks (5-6 months if arrested at EL4 stage).

Causes Ostertagiosis

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