First off, asprin will cause ulcers if used long term.
Second, "Too straight and doing worse every day" seems to be a genetic problem called Spastic phresis (sorry, I can't spell it right). It is a genetic disorder that several bloodlines of cattle have.
Not going to get better, only worse, until he will not be able to stand (possibly).
Your best bet is to get all drug withdrawl out of him and then sell him or butcher him. Sorry. Why prolong his suffering when he won't place well in a show anyway?