Hello. I have a three and a half year old border collie bitch. When she was around 12 months old she took a fall from about 6ft, and was absolutely fine until she rested later that day and then woke up and limped on her front left leg, it appears to come from the shoulder. I rested her for a week, exercised her and it returned, rested more and it went away and has not returned until now after some very heavy exercise, although there has been a few times in-between I thought there may have been something, but it was gone before I could be sure.. When she gets up she limps from the front shoulder for about three steps, stretches and is then absolutely fine, she will by choice jump and land on the arm, stand on it and shown absolutely no pain or weakness, very equal gait and stride pattern. The muscle is quiet equal in both of her shoulders and is happy for me to stretch the joint the same on both sides. Today I noticed a small lump at the top of her shoulder that was grain sized, she is microchiped and wondered if it could be the microchip? And would it be possible for a moved microchip to cause this lameness? I took her to a vet when she was 12 months with the problem and was given rest and a short course of Metacam. I took her back recently and am now being told she either has arthritis or a tendon injury. Anyone have any advice that could help? She is going for X-rays soon but any advice would be helpful.