you could try using tite liniment spray, good for warming muscles relieves pain helps bone strengthing in young horses.

im using this spray for my 15yr old gelding, ive had him for 12 mnths and he wnet lame just before xmas 2007 got over it and i noticed he had been favouing that leg, then he couldnt walk properly, chiropractor came out said its his shoulder he had an injury in the past, dosnt look good. been using this spray seems to be a bit of improvement some days he is more stiffer than others but the good news is hes not getting any worse. hope this can help you too. hope your horse is doing o.k