The aim of this study was to determine the levels of cytokines (TNF-α, PGE2, IL-1β, IL-6, IL-10) in synovial fluid samples from joints affected by osteoarthritis (OA), and to assess the efficacy of a single intraarticular (IA) injection of an autologous platelet rich plasma (PRP), mesenchymal stem cells (MSCs), bio-physically activated platelet rich plasma (B-PRP) and their combinations for treatment of OA in dogs. Thirty-six different breeds, gender, age and weight dogs affected by OA were used as materials. The groups were divided into: PRP, MSCs, PRP + MSCs, B-PRP, B-PRP + MSCs and SC (Saline Control). Only one dose was injected. The primary inclusion criterion for the dogs was that they had no systemic disease. The Genesis Cell System was used for preparation of autologous PRP, and the platelets were counted before injection. The Genesis Autologous Cell System 2 (30ml) was used as the bio-physical activator in preparation of the PRP. The bio-PRP physical activator device was mounted on one end and the other end of the activator was left empty. Biovalda Health Technology Inc. was used for producing allogeneic adipose stem cells. Cytokines (TNF-α, PGE2, IL-1β, IL-6, IL-10) in terms of quantities were measured using enzyme-linked immunosorbent assay (ELISA) from the synovial fluid samples before treatment and on the 0, 15th, 30th, 60th and 90th days of treatment. In all cases, clinic and radiographic examinations were performed on the 0, 15th, 30th, 60th and 90th days. The results obtained from the PRP + MSCs combination group were more successful compared to the other groups. It was noted that successful results could be obtained with PRP alone or in combination with stem cells, especially if repeated intra-articular injections are required. Also future studies are needed to understand the effectiveness of B-PRP. Only the B-PRP and MSCs combination were effective on many enzymes, but varying results were obtained in all cases.