Vaccinations for Adult and Senior Cats
Vaccinations are lifesavers. They protect your cat from many communicable and serious diseases by triggering protective immune responses and preparing them to fight future infections from disease-causing agents.
The American Association of Feline Practitioners offers guidelines for vaccinations in cats that many veterinarians follow. They distinguish two categories of vaccines: core and non-core. Core vaccines are those that all cats (with a few exceptions) should get: rabies, feline panleukopenia (feline distemper), feline herpesvirus, and feline calcivirus.
Non-core vaccines are those that only some cats, depending on their lifestyle and environment, should get: chlamydia, feline infectious peritonitis, FIV, bordetella, and feline leukemia virus. For cats that live outdoors, or are exposed to other cats known to be infected with certain communicable diseases, specific non-core vaccines may be a good idea. But for indoor cats, especially those in single-cat households or with housemates that have always lived indoors, non-core vaccines may not be advisable. While generally safe, vaccinations are not innocuous, and it's never wise to give more than needed.
Vaccination is a medical procedure, and as such, is not one-size-fits-all. A cat's risk of acquiring a specific infection depends in part on his age and health, exposure to other cats, and disease prevalence where he lives, and whether he goes outdoors. Your veterinarian can best advise you on what vaccinations your cat should receive.
The core vaccines, except for rabies, are usually given together in a "3-way" vaccine starting in kittenhood, with a booster one year later. Although subsequent yearly boosters have traditionally been advised, it is now believed that for most core vaccines, boosters every three years are equally effective. Cats at high risk of exposure may require more frequent boosters, and annual boosters for rabies may be mandated by law depending on where you live. Most non-core vaccines should still be boosted annually.
Your cat should be in good health when vaccines are administered, and should not have any conditions that compromise his immune system. This is one reason it's a good idea to have your veterinarian give them, rather than buying vaccine and doing it yourself. The veterinarian should check your cat's health before giving the vaccination. Another reason your veterinarian, rather than you, should give vaccinations is that you have no way of knowing the handling history of vaccine bought from a feed store or online source. Finally, it's important that vaccinations are given in specific anatomic locations on a cat. Although rare (about 1 to 2 cases per 10,000 cats vaccinated), vaccine-related sarcomas can occur at sites where vaccinations, particularly the feline leukemia (FeLV) and to a lesser extent, rabies, are administered. In the rare cases where tumors occur at these sites in later life, it's best to have them in places, such as the leg, that can be amputated to save the cat's life.
Veterinarians have now been requested to standardize and document where on the cat's body they administer vaccines. Specifically, panleukopenia, feline herpesvirus I, or feline calicivirus vaccines should be administered in the right fore region, or be given intranasally. Leukemia vaccines should be administered in the left rear region. Rabies vaccines should be administered in the right rear region.
It's not uncommon for a small lump to appear at the site of a vaccination, but it should go away in a few weeks. If it persists for more than three months, or if it's larger than about an inch in diameter, or if it's still increasing in size a month after vaccination, see your veterinarian as these may be warning signs for vaccine-related sarcoma.
Other adverse reactions, also rare, include neurological and visual disorders, pain and swelling at the injection site, fever, lethargy, and anaphylactic shock.
It's not presently known if geriatric cats need more (as some claim) or fewer (as others claim) vaccinations. Until more is known, the American Association of Feline Practitioners recommends that healthy older cats (and those with chronic but stable disease conditions) continue to be vaccinated just like younger adult cats.
The goal of vaccination is to vaccinate only as needed, but never less than needed.