So I noticed a few weeks ago my 3 yr old kitty Griffin was walking very weird on the back right. To me, it appeared his knee or hip popped out of joint. He exhibited no pain and as I approached him, it was clear my suspicion was correct. The kitty boys were running like wild animals through the house right before. Before I could get to him, Griff bolted off. Leg went back to normal. I made an appointment. Took him in Friday. Has a grade 2 luxating patella each knee. :( My vet (also ortho - did Samsons TT) says no surgery required right now. Several months ago I thought it looked like he was walking weird but then I got up to him and he was walking normal. I didn't think anymore of it. Just supposed to monitor and make certain the frequency of the flare-ups do not increase. Had the vet tech trim his nails as short as possible to prevent from catching in the carpet. Dr. Scott was amazed that I have 2 dogs with ortho problems and now a kitty! Just call me the Ortho Mom! :)