There are a variety of reasons to vaccinate indoor cats. The AAHA (American Animal Hospital Association) vaccination guidelines recommend vaccinating all cats with the core vaccinations (Rabies and FVRCP). Even if your cat never goes outside, he/she could be exposed to respiratory infections through the air if there are any neighborhood or stray cats that come near open windows or doors. If your pet ever slips out the door, it is best that he/she is protected. Also, if you ever plan on getting a new pet, it is best that your current pet be protected from diseases the new pet might carry.
Rabies is a human health hazard that could be transmitted from your pet to your family if your pet is not vaccinated against this disease. Colorado law requires that all dogs and cats be current on their rabies vaccination. There are always new situations that can arise, and it is better to know that your best friend is protected.