Canine septic arthritis

Septic arthritis is a relatively uncommon cause of lameness in the canine population (Bubenik and Smith, 2003); however, it is important to recognise this condition to minimise the chances of permanent damage and persistent lameness. Septic arthritis can be divided into two major aetiologies: haematogenous infections and direct inoculation of the joint via trauma or surgery.

Haematogenous arthritis can be initiated by a spread of infection from a focus elsewhere in the body, for example dermatitis or otitis, or spontaneously where a distant source of bacteria is not identified. In adult animals, haematogenous infections are often seen in a joint with pre-existing osteoarthritis, which is presumed to be related to the increased vascularisation of the affected joint aiding in bacterial invasion (Clements et al, 2005), while human healthcare literature suggests that neutrophils within osteoarthritic joints may have reduced motility and efficacy, potentially leading to reduced bacterial clearance (Dolganiuc et al, 2000). A thorough clinical examination is required to locate a potential primary focus of infection and allow differentiation from a true ‘spontaneous’ case.