Reba's got elbow AND hip dysplasia, which somehow managed to never got noticed till she was 11. She never limped much or showed any signs of discomfort till about 6 months or so ago. All of her vets figured arthritis till this year we finally had films taken and realized that she was so far gone that there's nothing to be done but pain remediation.
The sad part is that now she's so damn lame that she can't do any of the things she likes to do, like chase balls or squirrels or hike. So we swim. A lot. We found a couple of indoor doggie swimming pools that we go to as often as we can--once or twice a week.
Her saving grace is her muscle tone--she's always been a very active dog and that's the only thing the vets figure is keeping her walking. So swim, swim, swim, keep your dog in shape, keep the weight down, keep those joints as strong as possible. Get your dog on Synflex or Glycoflex, I am also supplementing with both Vit. C, E, and Fish Oil, which I figure can only help. Good luck--but from an old lady dog to a young dog, all I can say is that it doesn't necessarily mean the end of the world!