I have a 5 year old that was broke at 2 and had 10 months of training (reining) then sat in a field till right before I bought her last summer. This summer she was tripping on the right front suddenly so off to the performance horse vet we went and after a through exam they said growing pains in the knees and slight inflammation. We did shark cartilage and hyluronic acid injection then a previcox regimen. 

Noticed a difference right away and ran a second faster at our next race,  but we have made very few runs at this point, the tripping stopped but it's been about 6 weeks and the tripping has started again and she seems sore again. The vet said we could do weekly shark cartilage injections at home and see how that goes but I am wondering if something like Summit or another product would be better? I am having a hard time finding actual information verses people just selling the products saying they do this or that. 

Mainly looking to keep the joints lubricated and spongey to keep her feeling good long term and enjoying her job and take care of the inflammation. She is already on chia seed daily. 

Only because I am now paranoid, how is your horse's NECK?

My horse started tripping more on his front feet, worse on the right front. Turns out he had a pretty serious problem with his neck, where the vertebrae were tilted and pressing on his spinal cord. Obvious sudden retirement.

So that's immediately where my thoughts go when horses are tripping, and there isn't obvious signs in the front feet or legs.

If you didn't even make it 6 weeks, then I think there is something else going on that you need to find. Back to the vet! In my opinion, tripping is NOT normal.

I use compass for my almost 18 year old and 7 year old. I think injectable joint supplements work more than the oral ones.