Micromorphometry a nd C ellular C haracteristics o f the C anine Cervical I ntervertebral D iscs

Results: The NP from CH dogs was smaller, more rounded, and more dorsally located compared with that from NCH dogs. The NP occupied a greater proportion of the disc in NCH dogs compared with CH dogs (27.7 versus 15.8%; P o .001). The ratio of ventral to dorsal AF was approximately 3 : 1 in the CH group and 2 : 1 in the NCH group. Cellular variables were region dependent. Cell density was 2.4-fold higher in the OA compared with the NP. Approximately 50 of NP cells and 4.5% of OA cells occurred in groups. Conclusions and Clinical Importance: Micromorphometric variables differed by CH status. Cellular variables differed by disc region. Our findings potentially can explain the high incidence of intervertebral disc extrusions in CH dogs compared with NCH dogs.