The Dog as an Animal Model for Intervertebral Disc Degeneration?

Prospective observational and analytic study. To investigate whether spontaneous intervertebral disc degeneration (IVDD) occurring in both chondrodystrophic (CD) and nonchondrodystrophic dogs (NCD) can be used as a valid translational model for human IVDD research. Different animal models are used in IVDD research, but in most of these models IVDD is induced manually or chemically rather than occurring spontaneously. A total of 184 intervertebral discs (IVDs) from 19 dogs of different breeds were used. The extent of IVDD was evaluated by macroscopic grading, histopathology, glycosaminoglycan content, and matrix metalloproteinase 2 activity. Canine data were compared with human IVD data acquired in this study or from the literature. Gross pathology of IVDD in both dog types (CD and NCD) and humans showed many similarities, but the cartilaginous endplates were significantly thicker and the subchondral cortices significantly thinner in humans than in dogs. Notochordal cells were still present in the IVDs of adult NCD but were not seen in the CD breeds or in humans. Signs of degeneration were seen in young dogs of CD breeds (