I really feel for you. This situation seems very tricky with all your other commitments. Where are you? Perhaps one of us can help with some practicalities at least? He sounds grass sensitive to me.
I hope the vet visit went ok and you got some answers. I do not think anyone was nasty on this thread. People were just concerned that the vet was not getting to the bottom of the lameness issue as its been going on so long. Simply running up bills with no proper diagnosis after 6 months is not good. I certainly did not mean any offence by anything I said. I just did not like to see things going round in circles for Bert.