Placental pathology of experimentally induced enzootic abortion in ewes
Novilla, M.N.; Jensen, R.
American Journal of Veterinary Research 31(11): 1983-2000
1970
ISSN/ISBN: 0002-9645 PMID: 4099192 Document Number: 26550
Thirty pregnant ewes were inoculated i/v with the Arkoosh 1-1 strain of Chlamydia ovis at the 90th day of gestation. They were killed 20, 30 and 50 days after inoculation or immediately after abortion. Eleven ewes aborted 6-44 days after inoculation. The placentae recovered from ewes aborting after 6-11 days were autolysed; those from ewes aborting after 35-44 days had lesions typical of enzootic abortion. Oedema of the chorioallantois and accumulation of a reddish-brown exudate around and between the placentomes were observed in the placentae of non-aborting infected ewes. Early microscopical changes were found in the septal cells of the hilar region of the placentome, infection extending deeper as the disease progressed, resulting in the accumulation of a sanguino-purulent exudate containing the organisms.