Any Tips for the Arthritic Dog?

Hi I have a 6 year old yellow labrador. She was diagnosed with arthritis in one of her front legs when she was 2. She has been on Metacam ever since. The last few months she has been really slow I know that it is worse in the winter months. My vet says that all they can give is Metacam. It saddens me to see her limp and go slow as she is not an old dog, I just wondered if anyone had any tips that could help. Much appreciated. Thank you.