Abortion associated with toxoplasmosis in sheep in Oregon.

Toxoplasmosis was diagnosed in an ovine fetus from a farm in Eddyville, Ore. Of 34 ewes on the farm, 30 aborted during the 1979 lambing season. One fetus and accompanying fetal placenta were submitted for diagnosis. Focal necrosis, calcification of cotyledons, and tachyzoites of Toxoplasma gondii were found in the placenta. The fetal heart was infiltrated with mononuclear cells, and numerous T gondii cysts were in the myocardium.