RESUMEN
OBJECTIVE: To demonstrate the efficacy and safety of mesenchymal stem cells (MSCs) for xenogeneic use with intra-articular administration in dogs with osteoarthritis. ANIMALS: 80 client-owned dogs with naturally occurring osteoarthritis in elbow or hip. PROCEDURES: A multicentric, double-blinded, parallel, randomized and placebo-controlled clinical trial was performed. After intra-articular injection of equine umbilical cord MSCs, dogs were reexamined at weeks 4, 8, and 12 using a force platform (gait analysis), orthopedic assessment, and validated owner questionnaire. Eighteen months after treatment, a long-term follow-up was done. RESULTS: Best results were obtained 8 weeks after treatment, where 63% of the patients showed an improvement in the gait analysis. Also 8 weeks after treatment, 77% of the dogs improved in the orthopedic examination; 65% of the owners considered that the treatment improved their pet's quality of life 8 weeks after treatment. The long-term follow-up revealed that 59% of the owners observed a duration of effect longer than 6 months after a single intra-articular injection of equine umbilical cord MSCs. No systemic or permanent adverse events were detected at any time point. CLINICAL RELEVANCE: Results of this study demonstrated the safety and efficacy of intra-articular administration of xenogeneic MSCs for the treatment of canine osteoarthritis.