THE term osteomyelitis, which literally means inflammation of bone, including the marrow and cortex, is most commonly applied to bacterial or fungal infections of bone. With rare exceptions, bacterial infections of the skeletal system do not constitute life-threatening events. However, they are of importance because they are a source of significant morbidity and, particularly in skeletally immature animals, debilitating secondary changes may occur if treatment is not prompt and appropriate. Viral and protozoan infections can also affect the skeleton but these, like fungal infections, are rare or undocumented in the UK. This article discusses the management of bacterial osteomyelitis and describes the pathogenesis of the condition, an understanding of which is essential for rational therapy.