It could be any number of things.Arthritis is one possibility.Have they tried putting her/him on a joint supplement. My horse was feeling a little stiff on his back end which is not normal for him.I had the physio and chiro out to him and he had a number of problems behind the stiffness.His poll,hip and a vertebrae were all out.
You would have to clarify exactly what you maen by stiffness? Does it ease with work, is it worse in the mornings, is it constant stiffness, does her stride shorten? etc. Don't panic yet it could be a number of things. Give me a bit more info and i'll try and help a bit more.
she 9 years old and been just in the field doing nothing for 3 years and my mate brought her yeserday for a very low price and we lead her to her new field but the more walking she done the better she got dont look stiff now it might of been as thay done nothing with her but we will she
I would tend to think that she is stiff having not done anything for a while. The fact that the more she moved the more she loosened up means that it is probably unlikely to be severe arthritic changes going on. You may find the fitter she gets and the more active she is that you see the problem going away. keep us posted.