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The common feature of members of this group is that the oesophagus is a column of doughnut-shaped cells. They are only distantly related to the other nematode groups and so drugs developed primarily for controlling strongyle and ascarid worms are often less effective against these.
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There are just three genera of veterinary importance:
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1) '''Trichuris''' (the whipworms)
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2) '''Capillaria'''
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3) '''Trichinella'''
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== ''Trichuris'' Species ==
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*The whipworms have a stout posterior end and a long narrow neck, which is superficially inserted into the caecal mucosa. *Eggs are brown, barrel-shaped, with a plug at either end, and can survive for up to 12years.
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*The infective stage is the embryonated egg.
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*The life-cycle is direct.
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*After the egg is swallowed, the larva initially forms a mucosal nodule before emerging into the lumen.
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== ''Capillaria'' ==
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*Similar to ''Trichuris'', but the difference between anterior and posterior ends of the body is not so pronounced.
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*Some species have direct life-cycles, others use intermediate or transport hosts.
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*Species have different predilection sites.
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*Of greatest importance in birds, species do occur in the urinary bladder and liver of cats and dogs.
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== ''Trichinella'' ==
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*This is known as the "worm that thinks its a virus".
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*It is a unique genus, and an important zoonosis.
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[[Trichuris]]
 
[[Trichuris]]
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