Sometimes a horse can develop lameness at the shoulder because of nerve damage... the mylin sheath travels over the shoulder blade at a notch in the blade... like when horse that pull carts or carraiges get a shoulder sweeney...? If x-rays don't show anything, it could be this or another soft tissue injury. good luck.

 shoulder soreness might actually be a injury or soreness somewhere else such as in the foot itself. Sometimes it can be a another leg/foot all together. Without a complete lameness exam and some xrays, its hard to say what is going on ( not to mention we are online and have no way to see the horse)

I'd be asking for more information from your vet rather than here.

Read my thread about the lame filly.It was only after an X ray that 2 vets could determine what was really wrong.

Our gelding that I mentioned earlier in this thread wasn't all that valuable a horse,either,in dollars and cents.However,being unridable rendered him WORTHLESS.We couldn't treat him in order to get him well and sell him without knowing what to do.Maybe rest is all your horse needs,but,time will tell if what you are doing is going to help.Good luck.

Been there,got the T-shirt!

 Thanks, I will probably get him x-rayed this next month. It's true,I can't get him sold this way. If I can get him sound then at least he can be a trail/family horse for someone.

Well,we had not been riding him,and didn't resume riding him,so,it's hard to tell exactly when it had  healed.The injury occurred in May,and,it was the following YEAR before we saw real improvement and he became ridable again.We sold him for the cheapest price we've ever sold a horse,to our farrier.I wish we had him back,he was a full brother to my black/white foxtrotter mare,and he was a strawberry sabino.Really flashy horse.Back to your question,the following year after the injury,we had to take him to an equine chiropractor twice because he had some back misalignment,he'd been compensating in his spine and other side because of the injury.

I know lots of folks would say that talk is a bunch of "doodley squat" but,we saw with our own eyes the improvement in his posture and gait after the chiropractor worked on him.We sold him shortly afterwards.

Nerves heal very slowly,something like .5 cm a month I think I remember (the vet) telling us that.

You might try a good linament on a regular basis,a local vet here recommended DMSO mixed in Nitrofurazone ointment which I did use,but,I don't like it because of the warnings on the Nitrofurazone label.Maybe a joint supplement since he is compensating on the "good" side with more weight.

Good luck.If there isn't any improvement in a few weeks,I'd spring for some XRays just to be sure you aren't letting something go too long.