To evaluate the effects of nuclear magnetic resonance therapy (MBST®) on the clinical symptoms of osteoarthritis (OA) in the elbow joints of dogs. In this double-blind study, 28 dogs with lameness caused by OA in the elbow joint were randomly allocated to two groups: 14 dogs received nuclear magnetic resonance (NMR) therapy [treatment group (TG)], and 14 dogs received a placebo [placebo group (PG)] over a period of 7 consecutive days. Visual and objective gait analyses were performed before treatment (M1) and at 3 (M2) and 6 months (M3) after treatment. At M2 and M3 Symmetry indices (SI) of the peak vertical force (PVFz) and the vertical impulse (IFz), lameness scores, and pain scores were compared with their values at M1 to calculate the overall treatment effectiveness (OTE) score. We also documented additional pain medication and medical physiotherapy during the time of study. Finally, we measured the range of motion (ROM) in order to evaluate the functional development of the joint. The median OTE score of dogs in the TG indicates no change after 3 month and was improved after 6 months of treatment. There was an improvement of the median OTE score of dogs in the PG after 3 months of treatment. Further, the OTE scores of dogs in the PG were actually worse after 6 months. Nevertheless, there were no significance differences in SIPVFz, SIIFz, ROM, and lameness- and pain scores between the TG and PG at M1, M2, and M3. When considering all collected parameters (excluding the ROM) to calculate the OTE, no significant difference between groups was measurable for the OTE. There was a positive effect of NMR therapy (MBST®) on the treatment of OA in dogs. However, future studies should investigate the mechanisms underlying NMR therapy and the pathophysiology of OA to provide optimal treatments for patients. Our results demonstrated that the response to NMR treatment was individualized for each dog. As an integral way of treating dogs with chronic OA, NMR therapy may be an alternative therapeutic approach to support traditional medications.