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| − | ===Histotoxic infections=== | + | ===[[Histotoxic Clostridia]]=== |
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| − | *Exotoxins cause local tissue necrosis and systemic effects which can be fatal - toxaemia
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| − | *''C. chauvei'' and ''C. septicum'' present in muscle as latent spores which can germinate to cause infection
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| − | *''C. novyi'' type B and ''C. haemolyticum'' have latent spores in the liver
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| − | *When inoculated into wounds, cause malignant oedema and gas gangrene
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| − | *Endospores persist in the soil
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| − | *Most ingested spores excreted in faeces, but some become dormant in tissues
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| − | *Tissue injury leads to reduced oxygen tensions allowing germination and replication of bacteria
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| − | *Exotoxins cause local necrosis
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| − | *Activated spores in the liver and muscles cause endogenous infections including blackleg, infectious necrotic hepatitis and bacillary haemoglobinuria
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| − | *Inoculation of wounds causes exogenous infections including malignant oedema and gas gangrene
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| − | ===''Clostridium chauvei''===
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| − | *[[Muscles Inflammatory - Pathology#Black leg|Black leg]]:
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| − | **Acute disease of cattle and sheep
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| − | **Endogenous infection in young cattle with latent spores in muscles, activated by trauma
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| − | **Exogenous infection via wounds in sheep of any age
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| − | **Gangrenous cellulitis and myositis caused by exotoxins leads to rapid death
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| − | **Skeletal muscle damage with lameness, swelling and crepitus due to gas accumilation
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| − | **Dyspnoea due to lesions in tongue and throat muscles
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| − | **Myocardial and diaphragmatic lesions can cause sudden death
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| − | **Fluorescent antibody test for diagnosis
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| − | *Causes [[Necrosis - Pathology#Gas Gangrene|gas gangrene]], along with [[Clostridium species#Clostridium septicum|''Clostridium septicum'']]
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| − | ===Clostridium septicum===
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| − | *Causes malignant oedema:
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| − | **Infection via wounds
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| − | **Cellutis with minimal gangrene and gas formation
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| − | **Tissue swelling die to oedema; coldness and discoloration of overlying skin
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| − | **Toxaemia with depression; death may be rapis if extensive lesions
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| − | *Causes braxy:
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| − | **Abomasitis of sheep
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| − | **Disease occurs during winter
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| − | **Rapidly fatal; anorexia, depression, fever
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| − | *Causes [[Necrosis - Pathology#Gas Gangrene|gas gangrene]] and [[Muscles Inflammatory - Pathology#Gas gangrene|myositis]]
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| − | ===Clostridium novyi===
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| − | *Infectious necrotic hepatitis/black disease:
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| − | **Acute disease of sheep, occasionally cattle
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| − | **Hepatic necrosis caused by exotoxins of ''C. novyi'' type B in liver damaged by ''Fasciola hepatica''
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| − | **Rapid death
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| − | **Dark discoloration of skin caused by subcutaneous venous congestion
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| − | **Fluorescent antibody test diagnostic
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| − | * Causes [[Necrosis - Pathology#Gas Gangrene|gas gangrene]] and [[Muscles Inflammatory - Pathology#Gas gangrene|myositis]].
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| − | *May be involved in [[Bacterial skin infections - Pathology#Systemic bacterial infections|cutaneous lesions]]
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| − | *Causes big head in rams - oedema of subcutaneous tissues of the head, neck and cranial thorax; necrotising lethal alpha toxin
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| − | ===''Clostridium perfringens'' type A===
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| − | *[[Necrosis - Pathology#Gas Gangrene|Gas gangrene]] and [[Muscles Inflammatory - Pathology#Gas gangrene|myositis]]
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| − | **Extensive bacterial invasion of damaged muscle
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| − | **Gas production causing subcutaneous crepitus
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| − | **Similar manifestations as malignant oedema
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| − | ===''Clostridium haemolyticum''===
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| − | *Causes bacillary haemoglobinuria in cattle, occasionally sheep
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| − | *Endogenous infection - endospores dormant in liver
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| − | *Fluke migration allows germination
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| − | *Beta toxin causes intravascular haemolysis and hepatic necrosis
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| − | *Haemoglobinuria due to destruction of red blood cells
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| − | ===Clostridium sordelli===
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| − | *Causes [[Necrosis - Pathology#Gas Gangrene|gas gangrene]], [[Muscles Inflammatory - Pathology#Gas gangrene|myositis]] and abomasitis (lambs)
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| − | ===Treatment of histotoxic infections===
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| − | *Early penicillin
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| − | *Vaccination with bacterin or toxoid at 3 months and booster after 3 weeks, then annually
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