People often wonder why it is recommended that they have their pet vaccinated every year, but rarely get vaccinated themselves after childhood. Traditionally, dogs and cats receive a series of vaccines as puppies and kittens, and then yearly booster vaccines for the rest of their lives. However, there are concerns about rare but serious adverse effects associated with vaccines. There are also questions about whether yearly vaccination is truly necessary for most pets and most diseases.

There is no doubt that the beneficial effects of vaccination greatly outweigh the risks, but even so adverse effects cannot be ignored.  Information about duration of immunity after vaccination, vaccine safety and disease rates need to be considered when determining how often to vaccinate an animal. Unfortunately, minimal information is available about how long most vaccines are protective in dogs and cats. So there is a logical tendency to err on the side of caution and vaccinate more frequently, rather than less.

New guidelines for vaccination of cats are now available from the American Association of Feline Practitioners.  The guidelines recommend longer intervals between vaccines in most older cats that have been previously (and adequately) vaccinated.

Rabies vaccination also has important legal aspects to consider. Different jurisdictions have different requirements. While a three-year rabies vaccine is available, many regions still require more frequent vaccination. Even if an animal is properly vaccinated with a three-year vaccine, if local rules require yearly vaccination, an animal vaccinated more than one year earlier could be considered unvaccinated. This can have a tremendous impact if the animal is exposed to rabies –  it could mean the difference between monitoring the pet at home, or a long quarantine, or even euthanasia. Therefore, it is important to consider the duration of immunity induced by the rabies vaccine used AND the local regulations.  Rabies vaccination is even important for indoor cats.

The bottom line is:

• Vaccination is an important part of your pet’s preventive medicine program.
• Different cats need different vaccination programs, depending on their age and what diseases they may be exposed to.
• Potential vaccine reactions should be reported to your veterinarian, who should then report them to the appropriate regulatory authorities, so that a better understanding of adverse reaction rates can be obtained.
• Don’t let vague fears of adverse reactions deter you from vaccinating your pet. If you have concerns, get informed, talk to your veterinarian, and get accurate information.

One last point…I think the biggest potential problem with moving beyond annual vaccination is the potential loss of annual veterinary exams. Particularly for older pets, I feel that the annual physical exam and veterinary consultation are much more important than vaccination. Regardless of a pet’s vaccination program, it is essential that a pet receives an annual veterinary examination to identify potential health problems as early as possible. Every few years is not enough.