Kongenitale okzipito-atlanto-axiale Malformation (OAAM) bei einem Schaflamm

A four day old male lamb of the sheep breed Pomeranian Coarsewool exhibited locomotory disturbances since birth. Its head was tilted to the right with insecure position. The lumbar spine was scoliotic. The lamb, which died spontaneously, showed a partial occipito-atlanto fusion, malformations of atlas and axis, a missing dens axis and a subluxation of the atlanto-axial joint in X-rays and patho-morphological investigations. These findings supported the diagnosis of a congenital occipito-atlanto-axial malformation (OAAM). The cause of the malformation could not be clarified. As this case was sporadic, it was not possible to draw conclusions on inheritance.