PATHOLOGY OF BOVINE ABORTION AND NEWBORN CALF DEATH CAUSED BY DUAL INFECTION WITH CHLAMYDIA-PSITTACI AND INFECTIOUS BOVINE-RHINOTRACHEITIS VIRUS

Nine aborted fetuses and one newborn calf, diagnosed as Chlamydia psit taci (C. psittaci) infection, were pathologically examined. The charac teristic lesions in the liver were focal necrosis in 9 aborted fetuses and granulomatous necrotic foci in the newborn calf. Moderate numbers of intranuclear inclusion bodies were found in necrotic foci of the l iver, spleen, thymus, lymph nodes, adrenal gland, kidney, lung and for estomach. Immunohistologically, a small number of C. psittaci antigens was demonstrated in necrotic foci of the liver and correlated with di stribution of elementary bodies. Moderate numbers of infectious bovine rhinotracheitis (IBR) virus antigens were also detected in degenerati ng and necrotizing parenchymal cells in various organs and correlated with distribution of intranuclear inclusion bodies. Thus, these aborte d bovine fetuses and newborn calf were interpreted as being dually inf ected with C. psittaci and IBR virus during pregnancy.