OK! Yay! I know so much useless crap about this!!
I have all of my horses on monthly Legend and Adequan. Yes even my "never taken a lame step" 7 year old. He has been on them since he was 5. Yes I know I'm crazy, I also get him "PPEed" twice a year. I'm anol.
I swear by these injections. Along with everyone else in the dressage world. Some people go so far as to do Adequan twice a month and Legend once.
Legend is HA, which is joint fluid. It basically just keeps the HA in high enough levels in the joint capsule, even under strain. These really only need to be injected once ever 4 weeks, any more is overkill and there's no added benefit. Legend is purely a preventative. It will never reverse damage, just keep more from happening.
Adequan is a PSGAG or Polysulfated Glycosaminoglycan. It basically serves to protect, strengthen and in some cases restore the cartilage in the joint. Where Legend just adds cushion, this stuff actually improves the structure and as far as for long term use, this is your stuff. In Nelson's case I would do the loading doses (ie. However many injections once every 4 days) and then continue by doing it once a month along with the Legend.
You can have horses on this stuff for a long time, as long as you can pay for it, that is. Getting the generics can reduce costs substantially, but there is no one to sue if your horse dies from contamination. I totally forget why Legend is more expensive.
Anyways in summary:
Legend and Adequan do not do the same thing!
You can inject them on a schedule of once a month for as long as your heart (and wallet) desires.
Injecting this stuff into the horse reduces any gastrointestinal risk and also works about a billion times better than oral supplementation. You may as well be feeding him sweet feed, because that's about the benefit you get form those oral supplements most of the time.
I have been using these injections for a few years and see no reason to ever switch back to oral supplementation. On all four horses I've used them on the results have been real. In my mum's older, arthritic horse you can always feel when it is time for his injections, and after wards he can run and play all day and come in to be ridden and be 100% sound, despite getting basically a death-by-arthritis sentence a few years ago.
Good luck! And talk to your vet! http://www.drsfostersmith.com/Rx_Inf...x_eq_psgag.pdf http://www.drsfostersmith.com/Rx_Inf...yaluronate.pdf