Little cat at the veterinary - getting a vaccine

There is no question that vaccines protect against disease – but they also present considerable risk. Sadly, far too many cats are still being over-vaccinated because too many veterinarians, and cat guardians, still think annual “shots” are necessary.

The American Association of Feline Practitioners (AAFP) recently updated its vaccination guidelines. The guidelines divide vaccines into core and non-core vaccines, and recommended that vaccination protocols should be tailored to the individual cat’s health and lifestyle.

Core vaccines

Core vaccines are those recommended for all cats. The feline panleukopenia
(FPV), feline herpesvirus-1 (FHV-1), and feline calicivirus (FCV) vaccines fall into this category. These vaccines are most commonly administered in a combination FVRCP vaccine.

Non-core vaccines

Administration of non-core vaccines should be determined based on an individual assessment of the cat’s lifestyle and exposure risk. The AAFP considers rabies, feline leukemia virus (FeLV),
Feline immunodeficiency virus (FIV), Chlamydophila felis, Bordetella bronchiseptica, feline infectious peritonitis (FIP) and dermatophyte vaccines non-core.

Rabies vaccines are required by many jurisdictions. While some rabies vaccines are only required every three years, the only non-adjuvanted rabies vaccine currently on the market is labeled for one year. Most feline veterinarians recommend this vaccine as a safer option to the three-year-vaccines, even though more frequent vaccination will be required.

Frequency of vaccines

Many factors play into how frequently cats should be vaccinated. There is no one-size-fits all approach, and it is imperative that cat guardians work with a veterinarian who practices individualized feline medicine. The cat’s health, age, lifestyle, and risk of exposure will all determine which vaccines the cat should get, and how frequently these vaccines should be boostered.

Why do kittens need a series of vaccines?

For the first few weeks of their lives, kittens ingest antibodies contained in their mother’s milk. These antibodies help protect the kitten from infectious diseases until its own immune system is more mature. Unfortunately, thse maternal antibody also interfere with a vaccine’s ability to stimulate the kitten’s immune system. To counteract this problem, veterinarians often administer a series of vaccines, usually beginning when the kitten is around six to eight weeks of age. Vaccination is then repeated at three- or four-week intervals. In some cases, the initial vaccine is not given until maternal antibodies have disappeared altogether.
Risk of vaccinations
Vaccines are implicated in triggering various immune-mediated and other chronic disorders (vaccinosis). Vaccines are also implicated in the high incidence of vaccine-induced sarcomas in cats. The incidence of these tumors ranges from 1 in 1000 to 1 in 10,000 cats. They can develop as quickly as 4 weeks or as late as 10 years post vaccination.

Although rare, vaccines can also cause serious allergic reactions. These reactions will typically occur within minutes to hours following vaccination. Symptoms can range from vomiting, lethargy, and diarrhea to anaphylactic shock.

Vaccine titers as an alternative to vaccination

Titer testing for a particular infectious agent measures the presence and level of antibodies in the blood. The presence of a measurable serum antibody titer indicates protection from disease. Discuss titer testing with your cat’s veterinarian as a viable alternative to vaccination.
If your cat is still receiving “annual shots,” discuss individualized vaccination protocols with your veterinarian, or find one who practices individualized feline medicine.

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This article was previously published on and is republished with permission.

10 Comments on Vaccines for Cats: Risks and Benefits

  1. It’s been standard practice in veterinary hospitals in CA anyway since the 80’s to vaccinate cats in the legs not in the scruff.

  2. Ingrid,

    I love browsing your site and you have great information, but seeing the photo here of the cat about to be injected in the scruff makes me want to both scream and cry.

    One of our cats was diagnosed with Vaccine Associated Sarcoma (and it had been at least 7 years since he had a scruff shot) almost a year ago. Thousands of dollars, 19 radiation treatments and a very aggressive surgery later, we’re hopeful we may have saved his life.

    I’m not an aggressive person by nature, but that photo makes me want to punch the person wielding the needle in the face!

    I know that you’re aware of the updated vaccination guidelines. Is it possible for you to either change out that photo or add a disclaimer / what NOT to do note?

    Thanks so much for the good work you do for our feline friends.

    • I’m so sorry about your cat, Bon. And you’re absolutely right, the photo used with this article is outdated when it comes to recommended vaccination sites. I was unable to find a photo showing the correct location, and have added a disclaimer.

      • Thanks so much, Ingrid. Maybe you could replace the photo with the one from the AAFP showing where vaccines should be administered, or the diagram with the Xs on the shoulder, hip & scruff?

        The disclaimer is helpful though, as too many cats are still being diagnosed and dying from VAS / ISS.

  3. Thunder got a severe allergic reaction the first time I got him shots, and I never did, again. He nearly died. He is an indoor cat. I do worry, though, about tracking something bad home to him, and I won’t touch any of the unvaccinated barn cats–which is tough for me because I want to pet them all!

    One of the cats, Princess, gets vaccinated, and I often pet her–but she is one of those unpredictable cats that will suddenly attack. She is very temperamental. She loves to sit on laps, but when you remove her, she will hiss and growl.

    All the cats are spayed and neutered, and usually just show up (are dumped) at the barn. We have lost a couple barn cats to feline leukemia, but there are some that are in their teens and thriving. One lived to 19–and never had shots. I guess it is a gamble with outdoor cats.

  4. Ingrid,

    My vet told me that indoor cats can be vaccinated for rabies every 3 years, even if they are just receiving the 1-year vaccination. What are your thoughts on that? I certainly prefer to have it done less frequently, especially for Lucky, whom I am unable to get into a carrier of any kind – the vet has to come to us, and even then, he has a terribly stressful time.


    • The 1-year rabies vaccine probably protects your cats against rabies for three years and beyond, but it is only licensed for one year, so in the eyes of the law, your cats are not protected. In the event that they come in contact with a rabid animal, or bite a human or other animal, they may be subjected to rabies quarantine by local authorities.

      Merial just released its new non-adjuvanted 3-year rabies vaccine. I’ll have more details about this vaccine in a post next week.

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