I use Boswellia with both my TB horses. One is 18 yrs and had a fracture in earlier days, I felt he was getting a little stiff at times and definitely think Boswellia has helped, he competes advanced medium dressage and no one believes he is 18!
The other had an operation on his stifle a couple of years ago, I use it as a preventative measure as worried it will catch up with him eventually. At present is great.
I use a human version and it certainly helps me!