as far as whats medicallly wrong I have no idea as what came to mind you mentioned she didnt have. looks like pain in the back and that right front leg. Something to mention is that xrays will only show bone damage such as fractures out of alignment etc. They will not show whats wrong with the soft tissues, tendons, nerves, etc. In order to see that the dog would need an MRI. a perfect example is my shoulder, xrays showed it was fine, and MRI revealed I needed surgery. my occupation is a nurse, had I not known what do because of being a nurse, the doctors would have kept pushing me away telling me to ice it and take some aspirin (took about 1 yr of bitching about my shoulder to get the insurance to approve the mri!).

anyways back on track here. My suspicion is that if an MRI is done it would reveal the issue I would suggest getting an MRI of the back and the right front leg joints. of note, the dogs excitement while outside may allow her to block out the pain, once back at rest the pain sets in.

my dog has had 2 surgeries on her rear legs, an acl surgery and an FHO surgery. If I allow her to overwork herself, which she WILL do because of her excitement, she will limp around for 2 days or so. I can no longer take her hiking because of this, she is now limited to short walks on leash, or about 20 minutes of off leash time in the yard.