THE PATHOPHYSIOLOGY OF CANINE BABESIOSIS - NEW APPROACHES TO AN OLD PUZZLE

The haemoprotozoan parasite, Babesia canis, is the cause of an economi cally important and potentially life-threatening disease of dogs in So uth Africa, the pathophysiology of which is incompletely understood. A vailable literature is reviewed, with emphasis on the pathophysiology of the anaemia and complications of babesiosis. The remainder of the r eview explores the possibility that pathophysiological mechanisms curr ently being investigated in human malaria and bovine babesiosis (in wh ich, as in canine babesiosis, an intra-erythrocytic parasite causes mu lti-systemic pathology) might also be active in B. canis infections. T he entity referred to as the multiple organ dysfunction syndrome is di scussed as a proposed mechanism within which apparently unrelated aspe cts of babesiosis form a predictable pattern. The molecular mediators of multiple organ dysfunction, including cytokines, nitric oxide and f ree oxygen radicals, are generated by host tissues, and are now under active study to help elucidate the pathophysiology of malaria. The sim ilarities between the manifestations of different diseases in differen t host species can be explained by the concept that the disease proces s is largely mediated by these molecules, generated by the host in res ponse to the parasite, rather than arising directly from the parasite itself. The current direction of malaria research provides a basis for future research into the pathophysiology of canine babesiosis.