Well the reason we think it's the shoulder is just the way she's moving. It's not severe, it's actually BARELY noticeable at the walk and even lounging at a trot, and slightly more noticeable with weight on her back. Here's what we've done (we being a trainer at my barn, the barn manager, and I) so far when she came up lame...
**Note -- I hadn't ridden her for 4 days before this happened so that's why I don't think it's the new saddle...the last time I rode her was last Sunday and then hadn't been able to do anything with her until Friday, and the lameness turned up when I brought her in from being turned out on Friday...I have seen her every day since Monday, just not ridden. I noticed her walking funny Fri when I brought her in, so it happened Fri while she was turned out.
1. Checked the affected leg for any swelling or heat, or marks...nothing.
2. Checked everywhere else on her body for swelling, heat, marks...nothing.
3. Cleaned out her hooves and then took a hammer and tapped firmly all around the underside, top, sides, back of each hoof to see if there were any reactions (looking for an abcess)...nothing.
4. Checked all down her neck and back for any reactions/soreness...nothing.
5. Poked and prodded her shoulder to check for soreness to touch...nothing.
6. Flexed her legs to check for anything there...nothing.
She hasn't really given us any obvious signs of anything, so at this point we just hand walked her a lot, and I've put liniment on her shoulders (both of them just in case), along her back, and over her rump too just to see if that would help. We've only been doing that a couple days now, so we'll see if we get any improvement.
The only reason we think it's the shoulder is just because at this point, with nothing else to go on but the fact that it happened while she was turned out Friday and she came in with grass stains, it's the only thing we can assume logically happened.
But based on ALL of the above, I'm open for any other suggestions that might fit and solve the mystery!! If it keeps up after the farrier sees her Tuesday and can possibly rule out hoof issues that we wouldn't have thought of, I'm just going to give up and call a vet. In the meantime, none of this seems to be bothering her so I'm not giving her any bute or anything. She seems happy as a clam she gets to be turned out each day and then no arena work!