My cat is naturally a bit chunky and had a luxating patellar ligament at a young age, which led to severe arthritis in his knee. He was never a jumper, but would run around the house, throwing his own toys and chasing them and his sisters. We haven't seen that in about two years, and he has a constant limp. We started treatment a little over a month ago, twice a day, hoping for good results. We started with the recommended 5 minutes per session and increased the duration over time. Not only has his limp improved, but he's also chasing his sisters again and playing with his toys. He's even eyed the scratching post as if he wants to jump on it. He was a little skeptical of the device at first, so we did a few trial runs without the light to get him used to it. Now I hold the laser out to him and ask if he'd like a knee treatment. He comes running, lies down, and stretches out his little leg for me to treat him. I'm so happy it's working for him and that his quality of life has improved with this simple and inexpensive treatment. It's definitely better than the constant trips and costs associated with a vet visit. While it doesn't show immediate results, the regular routine has definitely led to a significant improvement.