Ligaments will heal on their own it just takes time, if not torn too bad, tendons will not. My GSD had HD and arthritis in his spine, he was on Rimadyl but some dogs do not do well on Rimadyl for a long period of time. It's important to have the liver tested while the dog is on it. The one good thing about Rimadyl is that once the dog is taken off, if their are problems with the liver, the liver can reverse the effects and function normally (that is my understanding), if the damage is not too far gone. Navarre was on it for years. He was also on different glucosamine products over the years. He was on Synovi G3 and was doing well on that but it was a bit expensive (well he was a big boy and had to take 3 a day). Weight management is also a big issue with HD and keeping the dog exercised, to his tolerance of course and nothing strenuous. Good luck and hopefully he'll be feeling better soon.