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− | * Swine dysentery gives rise to fibrinous/ haemorrhagic enteritis.
| + | #redirect[[Brachyspira hyodysenteriae]] |
− | * A quite common and important disease.
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− | * The disease is caused by [[Brachyspira hyodysenteriae|''Brachyspira hyodysenteriae'']].
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− | ** Is not seen in gnotobiotic animals - other enteric pathogens such as [[Fusobacterium|''Fusobacterium'']] or [[Bacteroides|''Bacteroides'']] may therefore also be required in order to produce disease.
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− | * The disease is NOT systemic.
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− | ** Localised to the [[Large Intestine - Anatomy & Physiology|large intestine]]- in particular, the spiral [[Colon - Anatomy & Physiology|colon]].
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− | * Swine dysentery is spread by the faeco-oral route, and is carried by pigs and rodents.
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− | ===Clinical===
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− | * Affects post weaning pigs at approximately 4 months of age.
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− | * White scour becomes a liquid dirty red / brown scour with a foul smell.
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− | ** Contains poorly digested focal shreds of mucosa and fibrin strands.
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− | *** '''Mucoid covered faeces'''.
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− | * There are three outcomes to infection; the animal may:
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− | ** Die
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− | ** There is a morbidity up to 90% in the herd, with up to 50% mortality.
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− | ** Recover
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− | ** Become chronically infected.
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− | * Symptoms are due to loss of absorption in [[Colon - Anatomy & Physiology|colon]].
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− | ** The [[Colon - Anatomy & Physiology|colon]] is normally a key site of absorption for water and electrolytes in the pig.
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− | ===Pathology===
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− | * The serosa of the spiral [[Colon - Anatomy & Physiology|colon]] may appear shiny from the outside.
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− | ** Is turgid and oedematous.
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− | ** In severe cases, haemorrhage may be seen.
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− | * The [[Small Intestine Overview - Anatomy & Physiology|small intestine]] NOT affected.
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− | * Fibrinous deposits are seen on the mucosa as the disease progresses.
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− | ** The mucosa underneath is eroded to expose blood vessels in lamina propria.
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− | *** Accounts for the bleeding.
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− | * Animals often recover, but have a low feed conversion ratio for sometime.
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− | ===Diagnosis===
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− | * Silver stains show organisms in the epithelium of the mucosa.
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− | *Clinical signs
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− | **''B. hyodysenteriae'' causes dysentry in weaned pigs 6-12 weeks old; pigs lose condition and become emaciated; appetite is decreased; large amount of mucous may be present in the faeces; low mortality; poor feed conversion ratio
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− | *Diagnosis
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− | **History, clinical signs and gross pathology
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− | **Anaerobic culture on blood agar with added antibiotics for at least 3 days
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− | **''B. hyodysenteriae'' causes complete haemolysis whereas other spirochaetes cause partial haemolysis
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− | **Immunofluorescence, DNA probes and biochemical tests
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− | **Serology using ELISA can be used on a herd basis
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− | **PCR
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− | * Also by immunofluorescence or electron microscopy.[[Category:Enteritis,_Bacterial]][[Category:Enteritis,_Fibrinous/Haemorrhagic]][[Category:Pig]]
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− | [[Category:To_Do_-_Clinical]]
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