Occurrence of Chlamydial Abortion of Cows in Niigata Prefecture

Abstract

Abortion of cows caused by Chlamydia psittaci (Cp) infection occurred at a region of Niigata Pref., 1988. Out of 17 cases, 15 fetuses were aborted at 129-221 days of pregnancy. Macroscopically, edema and enlargement of the liver, spleen and lymph nodes were noted. Microscopically, focal necrosis in the same organs was observed, and Cp specific antigen was demonstrated at the site of the foci by the indirect immunofluorescence antibody technique. Cp was isolated from the livers of the 10 fetuses tested. Specific antibody titer to Cp in the sera of the cows rose significantly after abortion. A considerablg high percentage of infection with Cp among cows in herds in the region was revealed by means of Cp isolation from feces and serological examination. However, route of invasion of Cp was unclear. These chlamydial abortions in cows may be the first confirmed cases in Japan.