Abortion in mice associated with Pasteurella pneumotropica.

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.