I have an indoor only cat. I live in a 3rd story apartment, so he is indoors at all times. Occasionally he will go out onto the screened in porch, which is of course isolated from other animals. He has no contact with any other animals. Does a pet such as this require annual vaccines? What could he possibly catch animal diseases from? The annual vet checkup and vaccines cost a little under $100, and for the checkup all they do is feel his body and listen with a stethoscope. So if I can skip it, I probably would!