BILATERAL PIGMENTED VILLONODULAR SYNOVITIS IN A DOG

Villonodular synovitis is an extremely rare condition of the synovial membrane in the dog, A 10-year-old, neutered crossbreed was presented with bilateral, progressive hindlimb lameness, Periarticular swelling was noted in both stifle joints. No craniocaudal instability was noted . Radiographs showed massive intra-articular soft tissue proliferation in both joints, with no bony involvement. Arthrocentesis was unsucces sful, Exploratory arthrotomy of the left stifle revealed a greatly thi ckened, florid, proliferative synovial membrane, An incisional biopsy was carried out and the histopathological diagnosis was chronic active villonodular synovitis, A radical synovectomy was carried out in the right stifle joint 10 days later. Corticosteroid treatment was initiat ed 10 days after the second surgery and continued for six weeks, with a continuous clinical improvement. Eighteen months after discontinuati on of the steroid therapy, the owners reported no recurrence of clinic al signs although a mild stiffness was still present.