The Combined Application of Intra-Articular Platelet-Rich Plasma Injections and Photobiomodulation Improves Clinical Outcomes in Dogs with Osteoarthritis—Results of a Long-Term, Double-Blinded, Crossover Study

Thirty dogs were equally assigned to a platelet-rich plasma group (PRPG), a photobiomodulation group (PBMTG), or a combined therapies group (PRP + PBMTG). Response to treatment was evaluated with weight-bearing distribution and different owner-reported outcome measures. Evaluations were conducted at 0, +8, +15, +30, +60, +90, +120, +150, and +180 days after the initial treatment. After the first 180 days, a crossover was performed, and a second 180-day follow-up was conducted. A second cross-over was performed, with a final 180-day follow-up. Nineteen males and eleven females were included, with a mean age of 9.4 ± 2.7 years and a body weight of 26.6 ± 3.8 kg. Six hips were classified as mild, eighteen as moderate, and six as severe. All treatments were able to produce clinically significant improvements in different evaluation modalities, with varied degrees of magnitude and duration. At the last follow-up, the combination of PRP and PBMT had a greater effect, showing a significant difference compared to the isolated treatments, with a moderate to large effect size. Kaplan-Meier estimators showed that PRP + PBMTG had more extended periods with better results. PRP and PBMT could improve objective outcomes and client-reported outcome measures in dogs with OA. Their combined use leads to greater, longer-lasting, clinically significant improvements.