This week’s case is an 11-year-old DLH cat with decreased range of motion in all joints and thickening of the soft tissues. What are your differential diagnoses for this cat?
Left carpus: There is thickening of the soft tissues surrounding the left carpus. The radiocarpal joint is subluxated on the oblique projection. There is osteolysis of the accessory carpal bone, and sclerosis of the subchondral bone of the carpal bones. Small osteophytes are present on the lateral and medial aspects of the joints.
Right tarsus: There is subluxation of the bones of the tarsal joint. There is marked smooth proliferation, most prominently surrounding the calcaneus. Regions of lysis and remodeling are present in the subchondral bone. There is marked soft tissue swelling surrounding the joint.
Immune mediated polyarthritis, feline progressive polyarthritis