A clinical trial of 60 dogs sought to evaluate the efficacy of pulsed signal therapy (PST) in reducing pain and increasing function in dogs with moderate to severe signs of osteoarthritis (OA). PST consists of the application of pulsed electromagnetic fields to the joint and periarticular tissues. There is some evidence of its efficacy in humans, but this has not been validated in dogs. Dogs were randomized into 2 groups—those ≥9 years of age and those <9. The control group was rested while the study group received PST for 1 hour for 9 consecutive days. Gait analysis and goniometry were performed before and after treatment. The Canine Brief Pain Inventory (CBPI) questionnaire—a validated survey of 10 questions rating chronic pain severity and interference in daily life—was given to owners, who remained blinded.
The PST group was found to perform better than the control group. While not clinically significant, peak vertical force, as measured by gait analysis, increased on average by 4.39% body weight, which approaches or exceeds other proposed ideals for improvement. Extension was also not significantly improved (4%↑); it was postulated that range of motion may have been more limited by mechanical means than by pain. Significant improvement was noted on the CBPI in both the severity (36%↑) and interference (44%↑) scores over baseline on day 42. This improvement suggests PST may be a useful adjunct treatment for dogs with OA.