Super Codlivine Supple Joint Supplement

First post from a long time lurker here!
I give Super Codlivine Supple Joint. I was a first time horse owner 2 years ago and my YO recommended I give him a general vitamin and mineral supplement. She suggested Codlivine. I started with the ordinary one, but decided that at 14 he qualified as a mature horse so changed to the Supple Joint. His coat got lovely and shiny soon after starting it and I hope that it helps his joints, but i don't think there's any way of knowing for sure, Is there?
 
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