Little cat at the veterinary - getting a vaccine

Guest Post by Fern Slack, DVM

Vaccination against debilitating and fatal diseases has vastly improved the well-being of humanity.  It’s difficult now for us to imagine a world with widespread polio, kids dying daily of whooping cough, or smallpox decimating whole cities.  Without our indispensable vaccination programs, such diseases would re-emerge quickly.   It does not follow, however, that an individual will achieve better health through more frequent vaccination, nor will the population as a whole.  Neither does it follow that the best vaccine plan for a child in, say, South Africa would be the same as for a child in Canada.

Likewise, there is no single vaccine protocol that is right for all cats.  Every cat has different risk factors.  And while many mistakenly believe that vaccinations are entirely safe, and entirely effective, neither is true.  There is always a risk of adverse events associated with vaccination, which must be balanced against the benefit, if any, from a vaccine for your cat.  Yet the serious and often fatal diseases we fight with vaccines are still out there.

The Diseases Most Cats Should Be Protected Against

Panleukopenia (“Feline distemper”) used to be a common veterinary hospital visitor, highly contagious and commonly fatal. The virus is a resilient organism which can sneak into your house on your clothes or shoes.  Indoor cats must therefore be protected.

The “distemper” combination vaccine includes antigens for Feline Viral Rhinotracheitis and Calici virus.  While rarely fatal, both diseases cause much easily preventable suffering.

Indoor cats must also be protected against Rabies.  It is contagious to humans, and is nearly 100% fatal if not treated immediately.  Cats are very susceptible to it.  Vaccination laws are strong, as they should be, to protect the citizenry.  Fortunately, there is a feline vaccine available that utilizes a unique technology which delivers excellent protection with minimal inflammation.  If other, unnecessary vaccines are eliminated, the repeated administration of such a relatively innocuous one can be better tolerated.

Only these two vaccines, the Rabies and the Panleukopenia /Calicivirus / Viral Rhinotracheitis combination, are recommended by the American Association  of Feline Practitioners for all cats, including those living completely indoors.

Other Available Vaccines

Feline Leukemia (FeLV):  The FeLV vaccine is worthwhile, but only for cats who spend time outside or have other lifestyle factors that put them at risk, such as living with another cat who has the Feline Leukemia virus.  Even then, the level of protection against a strong challenge in a vaccinated cat is far from perfect.

Feline Immunodeficiency Virus (FIV):   FIV is not a significant risk for most cats, because contagion nearly always requires a bite wound.  It should be used only for cats at demonstrable risk, such as outdoor cats who fight.  This vaccination induces antibodies that can’t be differentiated from those produced by actual infection, so a vaccinated cat will always test positive, complicating identification of cats who actually have the disease.  This is not a vaccine to be used lightly.

Chlamydophila felis:   A nearly useless vaccine which is included as a fourth ingredient in many of the commercially available “distemper” vaccines.   The addition distracts the cat’s immune system from the other three, much more important antigens, while engendering nearly no effective protection itself.  Unless there is a specific, test-confirmed need for it, this should not be used.

Feline Infectious Peritonitis (FIP):  There is no measurable benefit from this vaccine for almost any pet cat, but it still poses all the risks of the “good vaccines”.  Avoid this one entirely.

Serious Risks Associated With Vaccination

Vaccine-Associated Fibrosarcomas:  Also known as injection site sarcomas, these are very malignant cancers which arise at the site of an injection.  The incidence is estimated at between 1 in 1,000 to 1 in 10,000 vaccinations.  These tumors must be treated extremely radically.  For this reason, some vets now administer feline vaccines as far down the legs as possible, and sometimes even in the tail.   Should tumors occur, amputation of a limb can save the cat’s life.

Inflammatory Insults:  Much worse and probably more common is the danger deriving from repeated inflammatory insults.  Many leading scientists now believe that vaccinations induce systemic inflammatory responses, which can lead to chronic inflammatory diseases such as arthritis, pancreatitis, and inflammatory bowel disease, as well as hyperthyroidism and numerous others.  The actual risk for a given cat is likely to be closely proportional to how many vaccines he receives over his life.

Anaphylactic Reactions:  True anaphylaxis is quite rare, but does happen.  Even with immediate treatment, death may ensue.

Vaccination can cause many lesser problems such as itching, hives, lethargy, vomiting, diarrhea, and local hair loss, to name a few.  Most of these are transitory, and are not serious health risks.

Protection With Minimal Vaccination

Where possible, I recommend replacing annual or triannual vaccination with annual blood tests, also known as titer tests, which measure antibody levels.  If the titer is insufficient, and if there are no contraindications, I may recommend revaccination.  There are admittedly flaws in the concept of titering.  Most importantly, we don’t accurately know what level of antibody is protective.  Our evidence comes more from experience than from studies.  But that is changing, and hopefully there will be more reliable evidence to work with in the future.

Panleukopenia vaccinations induce an enduring immunity in most cats.  Many will carry a protective level of antibody for most of their adult life after only kitten shots and one adult injection.  Repeated vaccinations are usually not needed.  Some Panleukopenia vaccines are approved for 3-year intervals, but even that is more than is needed for most cats.  Titering is an excellent alternative for this disease.

There are titer tests available for Feline Viral Rhinotracheitis and Calicivirus also; single-ingredient vaccines can be given should your cat pass one titer and fail another.  Some of these can also be given as drops into the eyes and/or nose.  The lack of a “shot” reduces the risk of an injection site sarcoma.

The Best Of Both Worlds

Indisputably, every vaccination is an inflammatory event, and all inflammatory events have a systemic component, ripples from the stone thrown in the pond.  These insults may be small, but they add up, and so vaccinations should be kept as few as possible.  But don’t throw the baby out with the bathwater; a choice to avoid vaccines entirely leaves your cat at risk for some pretty horrible  awful diseases.  Vaccines are not all good or all bad.  They are tools to be used with good judgment for the right purposes.  The best vaccine plan for your cat will balance on the tightrope between disease risk and vaccine risk.   A good feline vet will take the time to learn about your cat’s lifestyle and history, and then help you learn about the risks and benefits of the vaccination choices to be made for your cat.

 Dr. Slack graduated from the College of Veterinary Medicine at the University of Georgia, and has been working exclusively with cats since 1993. She is the owner of Uniquely Cats Veterinary Center in Boulder, CO.


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16 Comments on Feline Vaccinations: Walking Through the Minefield

  1. My 12 year old cat has NEVER been vaccinated for anything. I am grateful that my state allows for rabies waivers.

    I strongly believe the leading causes of feline cancers are vaccines, pesticides such as flea/tick treatments, heartgard and commercial diets. I believe less than 25% is environmental and of course we tend to discount genetics.

    • Hi Diane, my 18 year old cat has NEVER been vaccinated for anything, AND she is an indoor/outdoor cat (on a secluded farm). My state (Illinois) does NOT regulate rabies vaccines for cats at all. Instead the regulations are set up county to county, and my county does not require them. However, she has not been vaccinated mainly because she seems to get sicker at the vet instead of better, and after a few years of avoiding the vet she seemed to get along just fine without them.

      My cat had 2 companion cats she was bonded to (her aunt and her mom) who were not vaccinated either, but passed at ages 12 and 15 of feline cancer. I myself am a human cancer research scientist, and while environmental factors do play a role in some cancers, including crop pesticides and second-hand smoke, they alone cannot cause cancer, they just cause damage and it’s up to cells as to whether they can recover from that damage. I am pretty sure vaccines, flea/tick/heart treatments, and commercial diets do not lend contributing factors to the development of cancer in cats. If you knew how cancer works you would understand, but it is an in depth subject matter that most cannot grasp until they make it their career to understand it. Basically, cancer is due to inherited genetics in so many cases, and in most of the other cases cancer is completely random, but no matter what cancer is caused by abnormal DNA. Every time one cell divides something could go wrong, and well, humans and animals alike have trillions of cells that divide every day. That is why cancer is common in old age, in humans and animals, because the more times your cells have divided the higher the statistics that something will go wrong in DNA as it replicates and separates, and cancer begins literally with one cell that somehow became abnormal due to a change in its DNA. Only very strong and dangerous chemicals are able to damage DNA.

      I guess what I am trying to say is: beliefs are not science.

      • Thank you for your comment, Amanda. While I agree that many factors play into whether a cat (or human, for that matter) will get cancer, I think it still makes sense to avoid exposure to environmental toxins, chemicals, and other potential contributors to cell damage – and that includes not over-vaccinating our cats. We can’t control genetics, but we can control these other aspects up to a point.

        • Less than a month ago I took my 8 year old perfectly healthy perfectly happy cat to the vet for annual vaccine and check up. He is an indoor cat, but they were adamant that I give him a rabies shot amongst others. Within 24 hours diarrhea vomit and a temperature of 104, he was hospitalized overnight. Sice this incident I have spent close to $2000 dollars, it was $650 for the overnight stay at the vet who gave him the vaccine, but the cat never fully recovered so I took him to another vet. They tell me he has pancreatis, and have him on pills twice a day and B vitamin shots once a week, which is adding up. However nothing has changed the cat still has diarrhea and vomit once or twice a week, and doesn’t use his litter box for diarrhea which hasn’t happened before. They are now recommending an ultrasound for $500 more. My question is will the cat ever recover, I don’t mind paying to get him back to healthy, but I cannot help but wonder if he will get better. He also seems depressed and doesn’t paly like he used too, he also constantly sleeps on the floor but was always on furniture before. Please let me know, if I should give up for my sake and the cats.

          • I’m so sorry your cat had such a horrific reaction to the vaccines, Steve. While it’s possible that that’s what set off his problems, he may also have had some underlying issues, and the challenge to his immune system from the vaccines may have pushed things over the edge, so to speak. I wish I could answer your question as to whether he will recover. Pancreatitis can be challenging to treat, but cats do recover from it. An ultrasound may give you additional information as to what is going on and allow you to make better decisions. All my best to you and your cat for a complete recovery!

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  3. I vaccinate when they come in, and keep up with rabies because it’s a state law, but after that I figure immunity is immunity and doesn’t wear off. I don’t have to get my shots every year, why should my cats?

  4. Glad you all found the article helpful.

    Esme, so far I love Raven Stole the Moon. I met Garth Stein at a book talk Friday night, he was wonderful!

  5. Thank you for this informative discuss on vaccines. You will have to tell me what you think of Raven Stole the Moon-it is on my wish list.

  6. My Abbey has her titers checked for level of immunity and has been at good levels for the past 3 years so I don’t do anything but rabies for her. Saves money and worry about reactions once you get home. Good post. More information is always helpful. Thanks Ingrid

  7. This is great information. I like the fact that you give the statistics on how many cats get sick from the vaccines. I have several cats that get very sick from the vaccines but only for a couple of days. I think some of that depends on the company that makes the vaccine because when I changed vets, I didn’t have any more problems.
    Also, I have heard from my vet that after the age of 8 years,they really don’t have to have some of the vaccines any more. They do have to continue the rabies of course. Great post

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