Our soon to be 3 yrs old GSD will be having surgery on Thurs for torn ligament on her rear knee. We are also very active, our dog just loves going on agility equipment, playing hard with other friendly GSD's. It happens. As much as surgery scares me, I can see by delaying it she may develop arthritis, already has a bone spur due to joints not moving properly.
Thanks to Nova&Uschi'sMOm posting about the boxer story.