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| | [[Osteitis]] | | [[Osteitis]] |
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| − | ===Osteomyelitis=== | + | ===[[Osteomyelitis]]=== |
| − | [[Image:Cattle localised osteomyelitis with sequestrum.jpg|right|thumb|100px|<small><center>Localised osteomyelitis plus sequestrum (Image sourced from Bristol Biomed Image Archive with permission)</center></small>]]
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| − | *Mainly due to haematogenous spread in young animals
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| − | *Often as an extension from [[Joints Inflammatory - Pathology#Arthritis|suppurative arthritis]]
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| − | *Usually isolated: ''[[Actinomyces pyogenes]]'', [[Salmonella|''Salmonella'']], [[Escherichia coli|''E.coli'']], [[Klebsiella|''Klebsiella'']], [[:Category:Streptococcus species|''Streptococci'']]
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| − | *Metaphyses and epiphyses mostly affected
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| − | *Most infections are exacerbated by host response
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| − | *Pathogenesis:
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| − | **Prostaglandin and cytokines stimulate [[Bones - Anatomy & Physiology|osteoclastic]] bone resorption
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| − | **Blood vessel occlusion and tissue necrosis -> lack of removal of agent and cartilage -> cartilage thickening + persistance of infection
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| − | *Affected area may be surrounded by fibrous inflammatory tissue
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| − | *Metaphyseal abscesses may develop
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| − | *Sequestra may also develop -> surrounded by [[Granulation Tissue|granulation tissue]]
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| − | **Isolated from osteoclastic resorption
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| − | **May persist for long time
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| − | **Obstruct repair
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| − | *'''Vertebral osteomyelitis'''
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| − | **Lesions may affect the spinal cord
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| − | **Usually due to ''[[Actinomyces pyogenes]]''
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| − | **Suppurative inflammation may cause fracture of vertebral body -> dorsal displacement -> damage to spinal cord
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| − | **May form encapsulated abscess protruding into spinal canal -> spinal cord compression
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| − | *'''''Actinomycosis'''''
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| − | **= '''Lumpy jaw''' in cattle
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| − | **Caused by ''[[Actinomyces bovis]]''
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| − | ***Gram positive, branching, filamentous
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| − | ***Obligatory parasite of mucous membranes of [[Oropharynx - Anatomy & Physiology|oropharynx]]
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| − | ***Surface tissue is usually injured for infection to occur
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| − | ***[[Mandibular Osteomyelitis|Osteomyelitis of mandible]] -> destruction of bone -> replacement by fibrous tissue with pyogranulomatous nodules cotaining 'club colonies' of bacteria
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| − | ***Suppurative osteomyelitis
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| − | ***Fistulous tracts may discharge onto skin and into [[Oral Cavity Overview - Anatomy & Physiology|oral cavity]]
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| − | ***Excessive periosteal bone formation
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| − | ***Greatly enlarged mandible
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| − | [[Category:Bones - Inflammatory Pathology]]
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| | ===Periostitis=== | | ===Periostitis=== |
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| − | *Chronic periostitis - pockets of exudate and irregular new bone fomation | + | *Chronic periostitis - pockets of exudate and irregular new bone formation |
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| | [[Category:Bones - Inflammatory Pathology]] | | [[Category:Bones - Inflammatory Pathology]] |