2009 Volume 62 Issue 2 Pages 132-134
Atlanto-occipital fusion was found in a three-year-old Holstein cow that died of heart failure. The atlas had a large，vertebral body， fused with a basal part of the occipital bone. No occipital condyle was not recognized. In the atlanto-axial joint， no dens was observed in the axis. From these findings， it was considered that the vertebral body remained in the atlas due to a failure to divide at the dens. This is a rare instance for an adult cow.