I have not had to deal with this in my own dogs, but given the rescue I do, I see it all the time and just rescued a Berner pup that will be requiring hip surgery.
It really all comes down to how severe the dysplasia is - your dog should be evaluated by a Board certified orthopedic surgeon, not a regular vet. Vets are not radiologists and not trained to diagnose dysplasia ( I have yet to find one who has rendered a diagnosis accurate). Ideally, you would get his hips certified by either OFA or PennHip and you will then understand exactly the severity in each hip.
If severe, surgey may be the only option for a decent quality of life. Both the TPO (Triple Pelvic Osteotomy) and total hip replacement have their place depending on age, condition, amount of arthritic change, and muscle tone.
Less severe cases can do quite well with many of the things Patrick outlined - he should be on glucosamine and chondroitin every day for life (I like Synflex best for optimal absorption), as well as Adequan shots potentially. I also use Zeel and Traumeel, Wobenzym, Celadrin, and Hyarluronic Acid. Physical therapy, including swimming or underwater treadmill maintains synovial fluid in the joints without putting any pressure on his hips.....a great form of exercise for such guys.