disgusting butterfly (swallowtail)

Your cat is suffering from what we vets haven't found a word for. His condition is typified by total physical inertia, absence of interest in its ambience - what we vets call environment - failure to respond to the conventional external stimuli - a ball of string, a nice juicy mouse, a bird. To be blunt, your cat is in a rut. It's the old stockbroker syndrome, the suburban fin de siecle ennui, angst, Weltschmerz, call it what you will.