My 10 year old siamese has been acting a bit oddly for a few days.  He seems
more lethargic and he doesn't like being touched down lower on his back,
like near the tail.  He used to loved to be petted on the back.  But he
snaps his head around, as if it hurts him and he might bite.

He had this happen once before and I took him to the vet.  Had xrays done,
blood tests, the vet even shaved his back.  Nothing was found, but he
eventually got over it.

Now it seems to have come back!  Any ideas on what might be going on?

Thanks,

Nancy