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*Exotoxins cause necrosis, haemolysis and death
 
*Exotoxins cause necrosis, haemolysis and death
 
*Collagenase, hyaluronidase and DNase enymes facilitate spread through tissues
 
*Collagenase, hyaluronidase and DNase enymes facilitate spread through tissues
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===Diagnosis===
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*Anaerobic transport medium
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*Culture on blood agar enriched with yeast extract, vitamin K and haemin
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*Anaerobic culture with hydrogen supplement and 5-10% carbon dioxide for 48 hours
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*Colonies of ''C. perfringens'' are 5mm diameter, circular, flat and grey and surrounded by a zone of double haemolysis
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*Positive cAMP test with ''Sreptococci agalactiae''
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*Biochemical tests
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*Toxins identified in body fluids by toxin neutralisation or protection tests in lab animals
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*Nagler reaction to detect alpha toxin - plate neutralisation test
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*Fluorescent antibody tests for histotoxic clostridia
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*ELISA, PCR for toxin detection
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*Sudden death in unvaccinated farm animals may suggest ''C. perfringens'' types B, C and D
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*Post mortem
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*Gram positive rods present on intestinal smears suggests clostridial enterotoxaemia
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**Gas production causing subcutaneous crepitus
 
**Gas production causing subcutaneous crepitus
 
**Similar manifestations as malignant oedema
 
**Similar manifestations as malignant oedema
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===''Clostridium haemolyticum''===
 
===''Clostridium haemolyticum''===
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*Early penicillin
 
*Early penicillin
 
*Vaccination with bacterin or toxoid at 3 months and booster after 3 weeks, then annually
 
*Vaccination with bacterin or toxoid at 3 months and booster after 3 weeks, then annually
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===Diagnosis===
  −
  −
*Anaerobic transport medium
  −
*Culture on blood agar enriched with yeast extract, vitamin K and haemin
  −
*Anaerobic culture with hydrogen supplement and 5-10% carbon dioxide for 48 hours
  −
*Colonies of ''C. perfringens'' are 5mm diameter, circular, flat and grey
  −
*''C. perfringens'' colonies are surrounded by a zone of double haemolysis
  −
*Positive cAMP test with ''Sreptococci agalactiae''
  −
*Biochemical tests
  −
*Toxins identified in body fluids by toxin neutralisation or protection tests in lab animals
  −
*Nagler reaction to detect alpha toxin - plate neutralisation test
  −
*Fluorescent antibody tests for histotoxic clostridia
  −
*ELISA, PCR for toxin detection
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*''C. perfringens'' type E:
 
*''C. perfringens'' type E:
 
**Enteritis in rabbits, haemorrhagic enteritis in calves
 
**Enteritis in rabbits, haemorrhagic enteritis in calves
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===Treatment and control of enterotoxaemic infections===
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*Hyperimmune serum
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*Vaccination - vaccinate ewes with toxoid 6 weeks before lambing to allow passive protection of lambs
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*Vaccination of lambs with toxoid before 2 months of age to protect against pulpy kidney
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*Avoid sudden dietary changes
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