Pasteurella pneumotropica was isolated from the uteri, fetuses, lungs, and spleens of aborting Swiss Carworth mice. Male mice in the colony carried P. pneumotropica in pharynges, testes, and seminal vesicles. Normal pregnant and nongravid females carried P. pneumotropica in the eye of 1 and in the uteri of 4 of 11. Pregnant mice from another colony did not abort when injected with P. pneumotropica. Necrotizing and suppurative metritis was found among aborting females with P. pneumotropica infections. Occurrence of malignant lymphoma and mammary adenocarcinoma among animals in this colony likely resulted in immunosuppression which could have predisposed animals to the diseases seen.

Rabbits were inseminated artificially and inoculated 1 week later with rubella virus. The attenuated vaccine strain HPV-77 or strain 67-1127 which had been through 12 cell culture passages was used. Half of the rabbits in each group had been inoculated 1 month prior to insemination with the corresponding strain. Evidence of infection induced by either strain was obtained by immunofluorescence in lung, spleen, and placenta. Rubella virus antigen was also found in the lung of a 2-month-old rabbit of a dam inoculated with strain 67-1127. A high rate of stillbirths and neonatal deaths and poor weight gain occurred in litters of the 67-1127 group.