Surprise, surprise...our neutered male cat has excessive testosterone. That explains some of his aggressive behavior of late. He gave my wife a fairly nasty bite on the arm today, and that's a first. He's due for an ultrasound on Monday to ferret out the physical source of the problem. Luckily for George, he is normally a sweetheart whom we wouldn't give up for anything. So we think if the vet can get his testosterone level down, we think he'll be okay.
Have you seen that TV ad asking men if they have "low T"? Maybe we could make some money selling off George's surplus.