Submitted to: Veterinary Parasitology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: February 10, 2009
Publication Date: August 1, 2009
Citation: Dubey, J.P. 2009. Toxoplasmosis in sheep-the last 20 years. Veterinary Parasitology 163:1-14.
Interpretive Summary: Toxoplasma gondii is a single-celled parasite of all warm-blooded hosts worldwide. It causes mental retardation and loss of vision in children, and abortion in livestock. Cats are the main reservoir of T. gondii because they are the only hosts that can excrete the resistant stage (oocyst) of the parasite in the feces. Humans become infected by eating undercooked meat from infected animals and food and water contaminated with oocysts. A scientists at the Beltsville Agricultural Research Center describes toxoplasmosis in sheep. The results will be of interest to biologists, parasitologists, and veterinarians.
Sheep are important to the economy of many countries. Sheep are commonly infected with the protozoan parasite, Toxoplasma gondii. This parasite causes early embryonic death and resorption, fetal death and mummification, abortion, stillbirth, and neonatal death, largely dependent on the stage of pregnancy at which the ewe becomes infected. Until recently, the prevailing view was that most sheep acquire T. gondii infection after birth, and less than 4% of persistently infected sheep transmit it in the next generation. Recent studies from a group of researchers in England proposed that repeat ovine transmission of T. gondii maybe more common than previously believed. These findings have important bearing on sheep management. In the present paper, information on prevalence, transmission, and control of ovine toxoplasmosis is reviewed.