This is a tale of two cats - Roland, the original resident feline, and Schuyler, a re-homed stray. For years, Roland strolled his household alone, like a king, inspecting his realm with confidence.
Then Schuyler entered the picture.
As soon as Schuyler's status was changed from "stray in the backyard awaiting capture" to "indoor resident," the problems started between him and Roland.
Schuyler immediately launched a kitty coup d'etat, and poor Roland took the brunt of his urge to rule. Schuyler persecuted him mercilessly. Roland took to hiding out in the garage and trying to run away from home. Obviously, something had to be done. Roland was the senior cat; he certainly deserved peace and tranquility in his own home.
A couple of medications were tried from the limited arsenal then available, but they did nothing to modify Schuyler's behavior. I had almost resigned myself to having to give someone away, a heart-rending decision, when a "pet behavior consultant" moved to town and started a practice. I retained her to see if I could salvage the situation.
We started various programs to improve Schuyler's behavior. First, we kept them separated. Roland, as the first resident, wandered the house at will, and Schuyler was quartered in his own room, formerly a guest room. Early on, I leash-trained Schuyler. That allowed me to let him out in the house, tethered to the sofa, with the rest of us when we were home. Roland quickly learned the boundaries of the danger zone! As time went by, the various behavior-modification techniques that were simultaneously used began to show results. Schuyler soon could be trusted not to bother Roland - most of the time so he was allowed more freedom of movement around the house.
However, occasional lapses did occur, and when those occurred, the answer was "quiet time" for Schuyler. He was told, "No!" in no uncertain terms, and then unceremoniously scooped up and taken to spend 15 minutes or so locked in his room by himself. As an extremely social, in-your-face, people kind of cat, he didn't like that at all! But on the other hand, chasing Roland was one of life's great joys, or compulsions, and certainly not something to be given up lightly!
Finally, he reached an accord with himself about his priorities. I would see him sitting, flicking his tail, and looking toward Roland, with a pensive but mischievous expression on his face. I could see the mental wheels turning as he debated with himself. "How much do I want to chase Roland? Do I want to chase Roland enough to suffer the consequences?" Sometimes the answer is no, and he then trots off for a lie-down. But sometimes his eyes light up. "Yes! Do it!" He hunkers down, poised for take-off. Zoom! Galloping cats! In a second, Roland is atop the refrigerator, Schuyler looking up at him from the floor below. Schuyler's expression clearly says, "Gotcha!" He sits a few seconds, savoring his triumph. Then, without further ado, he turns, trots to his room, sits quietly, and waits for me to close the door on him.
As the years passed, the boys have mellowed. To this day, though, Schuyler still cannot resist the occasional impulse to play a game of "chase Roland," and Roland still doesn't like to play. But it's become a sort of ritual, now. The boys aren't great friends, but they tolerate each other without animosity. Roland has learned that it's the chase that counts for Schuyler, and that Schuyler really has no intention of catching him. That's just as well, because there's absolutely no doubt that Schuyler can run faster than Roland, who prefers strolling through what was once his private domain.