We bought a collar for our elderly collie a few years ago, but sadly she passed away soon after. We kept the collar and so glad we did. We took on a young rescued lurcher not long after, who became lame at the beginning of 2020. He had xrays, medications, joint supplements and a course of expensive injections. The vet was baffled as nothing showed on his xrays, but still he was stiff and limping. We had a support for his leg and kept him on the lead. I decided to put the collar on him as had just come across it in a bag of our old collies things.... 3 weeks later and his limp gas gone... off lead and chasing his ball again! I am so convinced that it has done the trick that I gave bought wristbands for my husband and myself who suffer from varying degrees if arthritis... only been on a couple of days so time will tell! Very very pleased though!