Heh.... Now that I search under the right name, I am finding that the AHSA and Racing Assns ban it. So that may just be the way it is.
Ah well.... we'll see. I'd rather keep him on it than try to see if I would rationalize that he still feels good off of it. His gait difference before he was diagnosed and put on it was so subtle most people didn't think he looked lame. But I could tell he was not as good as he had been the season before. My biggest hesitation is that a heavy conditioning program would do more harm to him than occasional pleasure trail rides would. He'd incur lots of wear and tear to get him to a point where he would be improved from the way he just 'is'. His job now is weekend trail horse and pet the rest of his time I think.
I don't know much about navicular so I shouldn't have an opinion on it:). But from the research my vet told me about it is that navicular is caused and worsened, by NOT enough conditioning. 1) I'm not trying to talk you into it or out of it, really, just discussing. 2) I would think a strong, physically fit horse would stay strong and physically fit longer then one not conditioned. 3) I would never say just suddenly start taking him out for hours at a time every day. I'd just say a common sense build up. And for this sport I don't call the conditioning I beleive you need to be "heavy". Build slowly to 3-4 times a week for 3 hour rides. Then about 2 weeks before a competion increase to 4-5 hours. 4mph, is not slow, but it's also not that fast. It does require some long trotting. I'd say the most important thing to look at in your situation is the terrain you'd be riding over. Rocky, hard, smooth, soft, hills? Etc.
Becky