Progression of joint damages in a colony of dogs with naturally occurring osteoarthritis: Results of an original 36-month longitudinal study

This longitudinal imaging study describes the natural progression of computed radiographic (CR) joint damages in a cohort of dogs with hindlimb osteoarthritis and their relationship with MRI findings. Fifty-one OA dogs and six controls were followed over three years using standardized radiographic and MRI scoring. Distinct progression trajectories (fast, slow, and non-progressors) were identified, with the stifle joint showing the clearest differentiation. Fast-progressors exhibited greater structural deterioration and stronger alignment between clinical impairment, radiographic damage, and MRI lesions. These findings highlight the heterogeneous nature of canine OA progression and the clinical relevance of repeated imaging.