Figure 4

Radiographs of the cranial cervical vertebrae of three Standard poodle dogs related to dog 2. The oblique lateral (A) and the ventrodorsal (B) views of the mother of dog 2, demonstrates a severe degree of dens hypoplasia (arrows). The oblique lateral view (A) also reveals a calcified body (arrowhead) between the dorsal arch of C1 and the spinous process of C2. The oblique lateral view of a brother of dog 2 (C) shows a normal dens (asterisk) whereas the oblique lateral view of a half sister of dog 2 (D) shows an absence of the dens.