Abortion and stillbirth associated with Chlamydia psittaci var ovis in dairy goats with high titers to Toxoplasma gondii.

During two consecutive breeding seasons in a brucellosis-free dairy goat herd, approximately 40% to 70% of the does (mean herd size, 14.5) had stillbirths or aborted. None of the does aborted or had stillbirths twice. In the first breeding season, 9 of 13 does aborted in the last 2 months of gestation. Three fetuses and 2 fetal placentas from 2 does were examined. Microscopic findings included severe multifocal hepatic necrosis, mild pneumonia, and mild multifocal necrosis in the brain. Cultures for Listeria monocytogenes, Chlamydia psittaci, and Coxiella burnetii were negative. Paired sera from 3 of the does that had aborted or had stillbirths were tested for antibodies to Toxoplasma gondii. On the basis of high titers, a tentative diagnosis of toxoplasmosis was made. During the following breeding season, 6 of 16 does aborted during the last 2 months of gestation. A total of 6 fetuses and 4 fetal placentas from 5 of these does were examined. Microscopic findings included infiltration of mononuclear cells around hepatic vessels and multifocal necrosis and gliosis in the brain. Chlamydia psittaci was isolated from the tissues of 1 fetus, 2 aborting does had persistent, high antibody titers against C psittaci (1:160 and 1:320), and all except 2 other does in the herd had C psittaci titers of 1:20 to 1:40. All but 2 does had T gondii titers of 1:32 to 1:4096. Evidently there was mixed infection with C psittaci and T gondii in this herd, but the former organism probably was responsible for the abortions and stillbirths.