Osteitis

Bone infections in general

• Caused by:
  • Bacteria most commonly (e.g. lumpy jaw in cattle due to Actinomyces bovis)
  • Viruses, fungi and protozoa less commonly

• Routes of infection:
  • “Inoculated” at time of fracture
  • Extension from other infected sites (sinuses, middle ear, joints)
  • Haematogenous (young farm animals)

• Gross lesions
  • Suppurative exudate (in bacterial infection), necrosis, bone proliferation, pathological fractures
  • Dead bone portions may be separated from blood supply and form bone sequestra

• Consequences
  • Extension to adjacent bone
  • Haematogenous spread to other bones and soft tissue
  • Pathologic fractures
  • Sinus tracts to exterior

• Osteitis = inflammation of bone
• Periostitis = inflammation of periosteum, usually develops from infection in adjacent tissues
• Osteomyelitis = inflammation of medullary cavity

Osteitis

• E.g.: Fusobacterium necrophorum in the foot, calf diphteria, bite wounds, extension from paranasal sinuses, compound fractures, extensions from infections in the joints, periodontal disease, Atrophic rhinitis