Well, they should certainly be seen on a regular basis. An annual visit, there are things other than vaccines that are important for that visit; having their teeth checked, checking their coat, checking their eyes, ears, things of that nature.
Now, an indoor cat is just not going to be as exposed to certain things, like a big one is feline leukemia, that an outdoor cat will. So a lot of vets now are advocating against over-vaccinating.
With the feline leukemia vaccine, there have been studies and actual proof that that actual vaccine can cause illness in cats. So you don’t want to give that to a cat unless they absolutely need it.
Most vets will talk to a client prior to the visit, and get a history -- kind of a window of the lifestyle of that cat -- to cater a particular vaccine protocol to that cat. So indoor cats, in my practice for instance, get rabies [vaccines], which all cats have to have legally. And generally will get a distemper vaccination up to a certain age. But we don’t always give leukemia vaccinations, because they don’t necessarily need it like an outdoor cat would. Unless your indoor cat also lives with an outdoor cat, in which case they should be vaccinated for everything the outdoor cat should be vaccinated for.