A retrospective study of sporadic bovine abortions, stillbirths, and neonatal abnormalities in Atlantic Canada, from 1990 to 2001.

In a retrospective study on 265 cases of sporadic bovine abortions, stillbirths, and neonatal deaths in Atlantic Canada (1990 to 2001), an etiological diagnosis was made in 117 cases (44.2%). The cases were divided into 2 groups: 234 abortions, and 31 stillbirths and neonatal deaths. Identified causes of abortion were bacteria (24.4%), fungi (6.8%), viruses (6.0%), protozoa (Neospora spp.) (2.1%), congenital anomalies (0.4%), and miscellaneous conditions (1.3%). In addition, placentitis without demonstrable infectious agents was observed in 17 (7.3%). Of the 31 cases of stillbirth and neonatal death, identified causes were dystocia (22.5%), congenital anomalies (22.5%), meconium aspiration syndrome (16.1%), and miscellaneous conditions (6.5%). No etiological diagnosis was made in 59% of abortions and 32.4% of stillbirths and neonatal deaths. The 3 most common identifiable causes of abortion in this study were bacterial, fungal, and viral infections.