Submitted to: Book Chapter
Publication Type: Book / Chapter
Publication Acceptance Date: June 10, 2004
Publication Date: June 30, 2004
Citation: Markus, M.B., Van Der Lugt, J.J., Dubey, J.P. 2004. Sarcocystosis. In: Coetzer J.A.W., Thomson,G.R., Tustin,R.C., Kriek,N.P.J. Eds. Infectious diseases of livestock with special reference to Southern Africa, Oxford University Press Southern Africa, Ni City, South Africa, pp. 375
Interpretive Summary: Infection by the single celled parasites of the genus Sarcocystis cause mortalty and loss of weight in livestock. Scientists at the Beltsville Agricultural Research Center and University of Pretoria in South Africa review sarcocystosis in livestock. This information will be of interest to biologists, parsitologists and veterinarians.
Species of Sarcocystis have a 2-host prey-predator life cycle, with herbivores as intermediate hosts and carnivores as definitive hosts.The intermediate host becomes infected with Sarcocystis by ingesting sporocysts, or oocysts, or both, excreted in the feces of the deinitive host. After a brief period of schizogony, the parasite encysts in muscles and forms sarcocysts. The definitive host becomes infected by ingesting sarcocysts in infected muscles of intermediate hosts. Some animals act both as intermediate and definitve hosts, but usually not for the same species of Sarcocystis. Sarcocystis is ubiquitous worldwide. The protozoon comonly and characteristically causes a chronic, subclinical infection in the cardiac and/or skeletal muscles of livestock, but, on rare occasions, Sarcocystis does give rise to disseminated acute disease, encephalitis (which can occur in the absence of disseinated infection), abortion or premature birth and, possibly eosinophilic myositis. In the present paper the biology of Sarcocystis infection in animals is reviewed.