The vet says that no one at their practice has ever heard of a pair of established housemates going at it for this long after a vet visit. I know that I'm guilty of terrible anthropomorphising, but I suspect that she's just pissed off. I also have to wonder if part of this is a power grab - the boy has realized that the dominent cat is old, and creaky, and was weak, and thought to himself in his little walnut brain "THIS is my time!"
He's handsome, but not the brightest crayon in the box.
So they're both getting Prozac. It's also the first time that my vet has felt obliged to drug *both* of the animals involved. Sigh. I'm "special." Great.
So we'll see how it goes. Because Upstairs Cat and Downstairs Cat is not an acceptable situation. At least I'm able to hide it in the food for the time being (although Downstairs Cat may be on to us.)