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==Description==
 
==Description==
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Cyathostomins are also known as small strongyles, and are one of the most important gastro-intestinal parasites of the horse. Over 40 species and several genera have been identified. The small, thread-like worms inhabit the caecum and the large colon with their developmental stages confined to the mucosa of the large intestine. Unlike the large strongyles, they do not undergo any extra-intestinal migration during development. Larvae ingested may develop to the L4 stage without interruption, leading to the characteristic 'pepper-pot' mucosal lesions seen with this type of disease. Larval emergence may occur throughout the summer and autumn, leading to the clinical signs associated with a 'wormy' horse (type 1 cyathostomosis). However, some larvae may become arrested at the EL3 stage and it is the mass emergence of these hypobiotic larvae that leads to the clinical disease of larval or Type 2 cyathostomosis.  
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Cyathostomins are also known as small strongyles, and are one of the most important gastro-intestinal parasites of the horse. Over 40 species and several genera have been identified. The small, thread-like worms inhabit the caecum and the large colon with their developmental stages confined to the mucosa of the large intestine. Unlike the large strongyles, they do not undergo any extra-intestinal migration during development.  
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Both an acute and chronic form of larval cyathostomosis occur in horses. The acute form occurs due to the re-emergence of hypobiotic thrid stage larvae from the intestinal wall, and horses are usually affected during late winter or early spring. It is usually individual, susceptible animals that are affected.
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The chronic form occurs when ingested larvae develop to the fourth stage without interruption, leading to inflammation and thickening of the intestinal mucosa. Larval emergence may occur throughout the summer and autumn, leading to the clinical signs associated with a 'wormy' horse.
    
==Signalment==
 
==Signalment==
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===Clinical Signs===
 
===Clinical Signs===
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Acute disease:
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* Acute onset, profuse diarrhoea
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* Pyrexia
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* Large numbers of thread-like larvae in faeces
 
* Large numbers of thread-like larvae in faeces
 
* Marked, rapid weight loss
 
* Marked, rapid weight loss
* Profuse diarrhoea
   
* Poor quality coat
 
* Poor quality coat
 
* Increased or decreased appetite
 
* Increased or decreased appetite
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Gross examination of faeces may reveal bright red fourth or fifth stage larvae. Larvae may be found on the rectal sleeve following examination.  Faecal egg counts may be low due to the disease being caused by emerging larvae.
 
Gross examination of faeces may reveal bright red fourth or fifth stage larvae. Larvae may be found on the rectal sleeve following examination.  Faecal egg counts may be low due to the disease being caused by emerging larvae.
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==Pathology==
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Post mortem examination of the large intestine may reveal larvae in the mucosa, seen as small grey dots (the characteristic 'pepper-pot' lesions seen with the disease). A catarrhal and haemorrhagic colitis and typhlitis may be seen, with hyperaemia or necrosis of the tissue. In chronic cases, thickening of the intestinal wall may be present.
    
==Treatment==
 
==Treatment==
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==Prevention==
 
==Prevention==
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==References==
 
==References==
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