
The answer is definitely YES. It does depend on the severity and dogs with very low hip scores can exhibit clinical symptoms whereas some dogs with high scores don't. From a purely personal (and I stress personal) point of view, I don't believe in massive exercise restriction unless clinical symptoms are very evident. I have a four year old shepherd with moderate HD, who does light agility (only 17" jumps). To date, and touch wood, she has never ever gone lame after exercise, agility or otherwise, and it does maintain her range of motion. She's not my first HD dog either. Ultimately, if the problem becomes too bad hip replacement is a great option, and my previous GSD had both hips replaced. Unless you are very rich though, it does mean you really need insurance cover, that was in place before the clinical symptoms became apparent, or before the diagnosis of HD.
The overriding thing for me is for my dog to enjoy it's life, it only has the one after all. I know of quite a few dogs who have not had HD, who have got some other problem develop and have had to be PTS at an early age. I try and apply this to me, if I had a physical problem, would I rather enjoy myself while the illness wasn't too bad, and have to slow down a bit earlier in later life, or have a bland life right the way through.
As I say, this is not advice, just my very personal feeling having and having had in the past, dogs with HD
Kat