With the apparent success of the recently completed canine vaccination series, I figure it’s time we turn our attention to cats. I’m going to attack the subject in a similar manner, dividing available vaccines into two categories — essential and situational.

By way of review, I define essential vaccines as those that are required by law and/or prevent especially contagious, widespread, or severe diseases. Situational vaccines are those that benefit only some individuals based on their lifestyle, age, geographic location, travel plans, and underlying health concerns.

The essential vaccines for cats are rabies, feline viral rhinotracheitis (herpes virus), panleukopenia (sometimes called feline distemper), and calicivirus. Every cat should receive these vaccines on a schedule known to provide them with continuous protection or (except in the case of rabies) be monitored via serology (titers) to determine when a booster is needed. Exceptions can be made when a serious health concern (e.g., a previously documented anaphylactic reaction or a current diagnosis of serious disease) makes the risk of vaccination higher than its benefits.

Rabies vaccines for cats are required by law in most states (See the AVMA’s listing for an up to date summary of rabies laws). State, local, and municipal statutes must be followed. Most do not recognize rabies titers as being a substitute for vaccination and will provide exemptions under very limited circumstances (e.g., a documented life-threatening reaction to a previous rabies vaccination in combination with a lifestyle that strictly limits exposure to wildlife and poses a negligible risk to public health). Many states only recognize rabies vaccines that are given by a veterinarian or under veterinary supervision.

Several different types of feline rabies vaccines are available and have different label directions. For example, the “older” types of rabies vaccines that have been associated with a higher risk of injection site sarcomas typically can be given when a cat reaches 12 weeks of age, boosted one year later, and then readministered every three years from then point on. The newer recombinant rabies vaccines do appear to be safer with regards to injection site sarcomas but need to be given at 12 weeks of age and then annually thereafter. Close attention to detail is needed to ensure that both the manufacturer’s label directions and all relevant rabies laws are followed.

Feline viral rhinotracheitis, calicivirus, and panleukopenia vaccinations can all be given according to the same schedule. In fact, they are often combined in a single “shot” that goes by the abbreviation FVRCP. Kittens should begin their vaccination series between six and eight weeks of age, and then receive a booster every 3-4 weeks until they are 16 weeks of age. The last dose should be given between 14 and 16 weeks of age to ensure the immunity derived from mother’s milk that can inactivate vaccines has waned. Depending on when kittens start the series, they will receive a total of either three or four vaccines. An additional FVRCP booster is given at the cat’s one year check-up. An adult animal with an unknown vaccination history should receive two FVRCP vaccines approximately 3-4 weeks apart.

Research has shown that the immunity produced by FVRCP vaccinations in adult cats lasts at least three years. Therefore, revaccination every three years or running intermittent titers to check antibody levels are both reasonable options. When a cat that has been vaccinated for FVRCP multiple times reaches an advanced age, which I define as around 15 or so, both vaccinations and titers can usually be stopped unless the risk posed by these diseases is especially high.

One question that frequently arises when discussing cats and vaccines is, “Do indoor-only cats need to be vaccinated?” My answer, with regards to essential vaccines, is “Yes.”

I can’t recommend that owners break the law as it applies to rabies vaccines, and if an indoor only cat bites someone it is still subject to all the quarantine and euthanasia/testing regulations that apply to individuals that go outside. Cats that are ostensibly indoor-only can also escape or be exposed to diseases that enter the home.

When it comes to essential vaccines, the benefits almost always outweigh the risks. This is not the case with situational vaccines, which we’ll start addressing next week.

Dr. Jennifer Coates

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