I would try PROMAXOL. It helps to decrease pain, inflammation, and stiffness and stimulate healing. Initially I would give a half dose with breakfast and again at supper. After improvement is seen you can decrease to a whole dose once daily. For longer term management you can switch to ARTHRO-IONX. In addition I find it helpful to follow a holistic approach by giving nutritional supplements to accompany the homeopathic. I would also use PROBIOTICS and OMEGA 3,6,9 to reduce inflammation and strengthen the body. I have found GeriForm, a choline/B vitamin supplement helpful for older dogs to improve neural function. What type of food and water are you giving? This also affects joint inflammation.
I would also suggest an evaluation by a veterinary chiropractor. If a correction is needed, that can help with better movement.
Please let us know how you do so we can help guide you.