Bacterial endocarditis and inflammatory joint disease in the dog

The main clinical features of 12 cases of bacterial endocarditis were lameness, pyrexia, lethargy, anorexia and systolic cardiac murmurs. The lameness varied from generalised stiffness to an inability to stand and walk. Multiple joint involvement was typical. Two types of joint pathology were identified. A marked synovitis with granulation tissue sometimes covering the articular cartilage was present in some joints associated with the presence of bacterial organisms. Other joints proved sterile and showed a milder synovial pathology. In many dogs both an infective arthritis and a non-infective arthritis co-existed. Bilaterally symmetrical joint involvement was typical of the non-infective arthritis. The pathogenesis of the latter was likely to involve the deposition of circulating immune complexes (bacterial antigens, antibody and complement) in the synovium. The infective arthritis was presumed to be secondary to embolic disease, ie, the spread of infected emboli from the heart valve to the joints. Treatment was unsuccessful in all cases.