Post natal development of canine caudal cervical vertebrae.
The morphology and post natal ossification of the fifth, sixth and seventh cervical vertebrae of 51 crossbred puppies (aged from birth to 12 weeks) were examined grossly, histologically and radiographically. At birth there were two centres of ossification, one in the vertebral body and one in the base of each pedicle of the neural arch. By one month of age secondary centres of ossification were present in the cranial and caudal epiphyses of the vertebral body. By two months of age these epiphyseal centres began to show signs of closure. Endochondral ossification of the neural arch occurred from a single centre of ossification within each pedicle with bony fusion of the laminae occurring by one month of age. In addition the dimensions of the neural canal were measured. The difference between the caudal and cranial sagittal diameters of each vertebra was 1 mm or less. It was concluded that, after one month of age, the shape of the neural canal can be influenced only by changes within the physes between the vertebral body and the neural arch or by the remodelling of bone formed by intramembranous ossification.
Department of Veterinary Clinical Sciences, Massey University, Palmerston North, New Zealand.
H M
HM
Burbidge
K C
KC
Thompson
H
H
Hodge
D000818:Animals; D002574:Cervical Vertebrae / Q000033:anatomy & histology / Q000000981:diagnostic imaging / Q000254:growth & development*; D004285:Dogs / Q000033:anatomy & histology / Q000254:growth & development*; D007403:Intervertebral Disc / Q000033:anatomy & histology / Q000254:growth & development; D010012:Osteogenesis / Q000502:physiology; D011859:Radiography; D013115:Spinal Canal / Q000033:anatomy & histology / Q000254:growth & development