> So I took her to the vet who checked her joints and could find no problem
When my English Mastiff pup started to limp (at about 5&half months old), the vet couldn't find anythong wrong with his joints on 2 seperate physical exams,, it was only on the 3rd exam that he noticed the TINYEST hint of a pian response in his face as he firmly moved his elbow. Xrays confirmed elbow displasia (UAP) and showed us also that the hips were fine (it looked as if he was limping on a rear leg too).
I know a Neo & an English Mastiff are not exactly the same, but they are both mastiffs - both giant breeds, both prone to growth related probelms and both very very good at not showing pain. I'm not trying to worry you and I do really hope your pups problem is a minor one, but don't rule out bone/joint problems on a physical examination only. More specifiacally, your breed is prone to pano.
If pup is worse at home (my pup managed to get rid of his limp every time we stepped into the vets), then take some vidoe footage at home to show to the vet, so they can see whats going on.
> ester-c to help her with her pasterns.
Who recomended it vet or breeder? Have you switched pup onto adult food to help with the pasterns yet?