462
edits
Changes
no edit summary
*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
===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 and 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
*Sudden death in unvaccinated farm animals may suggest ''C. perfringens'' types B, C and D
*Post mortem
*Gram positive rods present on intestinal smears suggests clostridial enterotoxaemia
**Gas production causing subcutaneous crepitus
**Gas production causing subcutaneous crepitus
**Similar manifestations as malignant oedema
**Similar manifestations as malignant oedema
===''Clostridium haemolyticum''===
===''Clostridium haemolyticum''===
*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
*''C. perfringens'' type E:
*''C. perfringens'' type E:
**Enteritis in rabbits, haemorrhagic enteritis in calves
**Enteritis in rabbits, haemorrhagic enteritis in calves
===Treatment and control of enterotoxaemic infections===
*Hyperimmune serum
*Vaccination - vaccinate ewes with toxoid 6 weeks before lambing to allow passive protection of lambs
*Vaccination of lambs with toxoid before 2 months of age to protect against pulpy kidney
*Avoid sudden dietary changes