glucosamine

["Beckstrom, Carolyn" <Carolyn.Beckstrom@standardregister.com>]

I am considering putting my horse on grand flex as a preventative.  He is
turning 7 and has never had a problem, but I would obviously like to insure
his continued soundness.  I know there is no proof that these supplements
prevent problems, but I figure it can't hurt and maybe help?   I know I
would have to discontinue using it 48 hours before a ride (at least ECTRA
sanctioned rides) and my question is - can this hurt the horse?  Will his
body be used to the supplement and then not produce as much of it's own
"lubricants" so if I stop using it and ask for hard exercise I could
actually cause what I am hoping to prevent?  Thank-you for your advice.
Carolyn and Gem in MA