Three years? Whoa. Is that based on your location, or the fact they're strictly indoors?

I'm freaking out right now because Loki (strictly indoor) is currently living with my parents who have Shadow (was supposed to be strictly indoor, but he had different ideas, and we eventually gave in), and it's been 14 months since her last rabies (which I intend on fixing tomorrow). (Shadow, by the way, is all up-to-date)