Thanks for the replies.
We got Duke as an 18 month old. We never noticed any problems in the past, up untill Tuesday afternoon, He seemed perfectly fine, Running around with our other Foxie, playing eating....
We rang his breeder last night and he said there was never a problem when Duke was a pup, And no problems in his blood line as far as he knows. He is going to do some research and get back to us.
We go back to the vet and pick Duke up soon, then we will know more.