Cat Vaccines: Answers to All Your Questions
There are people who think that cat vaccines are not necessary for their indoor cats. Later in this article, I will tell you a true story that does a great job of illustrating why this is not true.
Feline vaccinations are a necessary, but controversial part of maintaining cat health. Many years ago, before feline vaccines existed, many cats died of feline diseases that today are easily prevented. Cat vaccines are the necessary part of the equation, preventing these deadly cat illnesses from reemerging in an outbreak. Just like mumps and measles and polio vaccines have eradicated these once deadly diseases in the human population, the recommended feline vaccinations have done the same for cats.
Over the last years, there has been growing controversy over vaccines for cats. There have been many debates as to what vaccines cats really need, how often they need them, whether feline vaccines should be given for the cat's entire life, what the dangers of cat vaccines are, and many other aspects of the feline vaccination schedule.
What Vaccinations Do Cats Need?
With so many different vaccines available today and veterinarians spreading different information in their practices and online, it is certainly easy to understand why you may be confused about which vaccines your cats need and how often they really need them. Of course, there are special circumstances and exceptions to every rule, but there are generally 2, or in some cases 3, cat vaccines that are or should be given to cats on a regular basis.
Cat Rabies Vaccine
The feline rabies vaccine is one of the most important and highly recommended cat vaccines. Rabies is a deadly zoonotic (can be passed from animals to humans) disease that is spread most commonly through bite wounds from infected animals. You can learn more about the rabies virus on this page. This vaccine, because it is directed against a disease that can be transmitted to humans as well, is often required by state, county, or township laws.
This is the perfect spot to tell you the story I mentioned at the beginning of this article. During the course of my 20 years of feline practice, there have been numerous times when I have been told "Doc, my cat doesn't need vaccines; he never leaves the house".
There are actually many stories I could tell you about cat owners who have said that to me only to find out weeks, months or years later that their cat has slipped out the door when someone accidentally left it open.
Sometimes the owner gets the cat back right away, but often the cat is frightened and runs and hides, and it can be hours or days or even months before the worried cat owner is able to get their cat back.
Meanwhile, the cat is outdoors, exposed to other cats and their excrements. Possibly exposed to rabies or feline leukemia or at the very least some of the feline respiratory viruses. I have seen some sad endings to such events.
But perhaps the story that stands out most in my mind is about the family that had insisted there was no way ever that their cat could be exposed to anything, that he could never possibly get outdoors ...and then one night, they found him playing with a bat in their house.
The bat was sent to the state rabies lab for testing and it was confirmed that the bat indeed had rabies. The father, mother, and two children had to have rabies inoculations and their unfortunate cat had a choice of either being euthanized and submitted to the rabies lab for testing OR being quarantined in a veterinary hospital for 6 months for observation and isolation.
Fortunately, they chose the 6 month quarantine and the cat did not develop rabies and eventually was vaccinated and taken home. Needless to say, it was an emotional roller coaster for them and an expensive one at that.
I have other similar stories, but suffice it to say that one never knows for sure what can happen. Never say never. If you live in an area that has the rabies virus in the wildlife, vaccinate your cats for their sake and for yours.
While you should always consult a veterinarian, animal shelter or your state or local officials for requirements specific to your area, the American Veterinary Medical Association (AVMA) maintains a list of summaries of current state laws to give you a good idea of whether your cat needs rabies vaccines.
Feline FVRCP Vaccine (or FVRCP-C)
If you’re wondering what in the world all those letters stand for, you’re not the only one. Over the last 20 years, many of my clients have asked the same question. When I answer Feline Viral Rhinotracheitis, Calicivirus, Panleukopenia, and if the final C is part of the vaccine, Chlamydia, they look even more confused!
No wonder. That’s a lot of large, unfamiliar words.
This vaccine is more commonly called by a slang term, the cat distemper vaccine, which is really a misnomer. Dogs have a distemper virus which causes Canine Distemper, but cats don’t really have a version of distemper. Cats and dogs share some similarities in that panleukopenia in cats is caused by a parvovirus which is a relative of the parvovirus which causes Parvo in dogs, but neither is really related to Distemper.
At any rate, when you hear someone say your cat needs a distemper vaccine, just keep in mind it’s slang and cats aren’t really affected by a distemper virus. They are really referring to the FVRCP-C vaccine.
This vaccine is important for several reasons. As mentioned previously, the diseases caused by the rhinotracheitis, calici, and panleukopenia viruses used to kill many cats. With vaccination, we have been able to wipe out the most deadly effects of these diseases in our house cats, although these diseases still exist in feral colonies and other populations of unvaccinated cats around the world. If we were to stop vaccinating our pets, these diseases could re-emerge, bringing serious illness and death to the cat members of our families. With vaccination, these once deadly viruses now only produce mild symptoms in most cats.
Secondly, at least some of the respiratory viruses that the FVRCP-C feline vaccine protects against may never completely leave the bodies of infected cats. A good example is the herpes virus that causes Feline Viral Rhinotracheitis, the FVR of the FVRCP vaccine. Similar to the situation with people, once infected with a herpes virus (the type of virus that causes Feline Viral Rhinotracheitis), it remains in the body for life. Since some of these viruses can be deadly and cats can be carriers if the virus is in their bodies for life, then this vaccine is strongly recommended.
Feline Leukemia Vaccine
FeLV is the abbreviation given to the feline leukemia virus, which is the number one deadly viral infection in cats, spread through contact with any infected cat, including contact with saliva, urine, feces, bite wounds and even through a mother cat’s milk. Outdoor cats are at the most risk for contracting feline leukemia, or any cat that comes into regular contact with cats that carry the virus.
The FeLV cat vaccine is generally not recommended for strictly indoor cats that have no contact with outdoor cats. You should discuss your cat’s age, exposure risk, and environmental circumstances with your veterinarian to decide if this vaccine should be given annually to your cat.
Testing for the feline leukemia virus should always be performed when you first adopt a new cat. If you already have a cat, always test before you allow the new cat to be around your present one. There is a simple blood test that most veterinarians can do right in their office or they will send it to an outside lab and have the results the next day. Isolate your new kitty from all others until you have the results.
Other Cat Vaccines
Other vaccines, such as the ones for FIV and FIP, are not as effective as the three mentioned above, and because the protection rate is so variable, the American Association of Feline Practitioners does not recommend giving these cat vaccines on a routine basis.
(1) The feline FIV vaccine (referred to by some as the feline HIV vaccine or feline aids vaccine) does not cover all strains of the disease.
(2) Furthermore, the feline FIV vaccine will cause future tests for FIV to be positive. An unknown cat with a FIV positive test could be truly positive for the virus or could have received the vaccine. This interferes with the practice of good diagnostic medicine.
If, however, you and your veterinarian have decided your cat should receive the FIV vaccine (due to being at very high risk, etc.), then the cat should first have the FIV test. It is also recommended that the cat be permanently identified in some way, such as with a microchip, so that it will be evident the cat was vaccinated. However, keep in mind, because of the problem of vaccinated cats testing positive for the virus, you will then not have any way of knowing if your cat contracts the virus from another cat because the test would now be positive either way.
In my opinion, the level of protection against these feline diseases is not consistent enough to warrant the stress to your cat’s body or the risk of any serious adverse reactions that may occur. However, you should discuss any and all vaccines with your veterinarian based on your individual cat’s risk factors for exposure to these viruses and weigh the pros and cons for your particular situation.
The Feline Vaccination Schedule
When a kitten is young, he needs to be vaccinated against feline diseases more frequently than as he gets older as part of the process of building up adequate antibodies to diseases that could be deadly. This is especially important for kittens that have been weaned young, as the protection they would have been getting from their mother’s milk is missing from the equation.
The Rabies vaccine is given to kittens 12 weeks old and older in a single dose, with a booster dose to be given one year later.
The FVRCP-C vaccine should be given to weaned kittens at 6 weeks of age initially, with a booster given every 21 to 28 days after the previous vaccine until the kitten is at least 16 weeks old.
To clarify, if the vaccine is given to a 6-week-old kitten, it is entirely possible that your kitten will receive 3 doses of the vaccine (at 6 weeks of age, 10 weeks, and 14 weeks), but a minimum of 2 doses is recommended for all cats that begin the series when they are older than 16 weeks.
In other words, any cat older than 16 weeks of age with unknown vaccine history should receive 2 doses, given exactly 21 to 28 days apart, and then be given a booster one year later.
The FeLV vaccine is generally only given to kittens at risk for exposure to feline leukemia, although it is strongly advised by the AAFP to give all kittens the kitten series and then only booster them at one year and thereafter if they are at risk. The FeLV vaccine is given no earlier than 8 weeks of age, and in 2 doses, exactly 21 to 28 days apart, unless manufacturer recommendations dictate otherwise.
After the Kitten Series Vaccines
This is where the feline vaccinations schedule gets confusing for many cat owners, and while I would love to completely clarify it for everyone, doing so is impossible. Depending on the manufacturer guidelines for the vaccines your veterinarian uses, state and county laws, and many other factors, there are no set rules for how often cat vaccines should be given.
Generally speaking, once a cat has had their kitten series and a booster one year later, their vaccines should be spread out. As a general guideline, the American Association of Feline Practitioners outlines the following feline vaccination guidelines for veterinarians and cat owners:
The Rabies vaccine should be given as a booster one year after the initial kitten rabies vaccine and every three years from that point on.
The FVRCP-C vaccine should be given one year after the initial kitten series of vaccines and then every 3 years, unless otherwise instructed by the particular vaccine manufacturer.
The FeLV vaccine should be given every year, only to cats at high risk for exposure to feline leukemia and only for as long as the cat is at risk for exposure. (If an outdoor cat becomes an exclusively indoor cat, for instance, annual FeLV vaccines can be discontinued at that time.)
Again, these are simply the guidelines set forth by the AAFP, and your cat may need to follow a different feline vaccination schedule based on his/her individual needs, the vaccine manufacturer’s instructions, and or state laws or county requirements.
We don’t know completely how senior cats respond differently to vaccinations than younger cats, but research suggests that cats build up adequate immunity over time based on the number of routine vaccinations and the degree of exposure cats have had to a potential feline illness. For this reason, there are many special considerations to be made for aging cats and for any cat with an illness or chronic condition.
In my own experience, elderly cats are more likely to have a more serious vaccine reaction than a younger cat. The vaccine may affect their appetite for a longer period, may create a longer period of lethargy, and, therefore, may lead to dehydration which can be more serious in an older cat whose kidneys may already be somewhat compromised just from age.
Therefore, I take the vaccination of an elderly cat very seriously and evaluate each patient individually. I discuss the pros and cons with the owner and evaluate the need versus the risks for each vaccine.
The official recommendation is that cats with chronic but stable conditions be given vaccines in accordance with local laws, especially the feline rabies vaccine. However, each cat should be assessed individually by your veterinarian, and the recommendation for giving vaccines or holding off should be made by your vet. Most veterinarians will be willing to write a letter of explanation to any concerned individuals (such as landlords, airlines, etc.) in the event there is ever a problem with your senior or sick cat not receiving a cat vaccine.
For instance, a cat in my practice that was once diabetic and on insulin, but is now in remission would probably not be given a vaccine even though he is technically stable. This is because, despite his stable status, I would not want to do anything that would stress his immune system further and pose a risk for his cat diabetes to recur.
Of course, any cat with an acute illness or fever should not be vaccinated until he is well again and stable enough for the immune system to properly handle the vaccine. I have, much too often, seen young kittens with upper respiratory infections receive vaccines at shelters simply because “it is time” and then go on to become very ill and even die. This practice should be abolished.
Clearing up the Cat Vaccines Controversy
This vaccine controversy really began when an association was recognized, back in 1991, between cat vaccines and cancerous tumors, known as feline vaccine-associated sarcomas which were occurring at the site of the feline vaccination.
I was in my senior year at The University of Pennsylvania School of Veterinary Medicine that year, so I remember it well. One of my professors, Dr. Mattie Hendrick, began to document a relationship between cat vaccination and the increase in the number of tumors, specifically sarcomas, found in cats. This took place 3 years after the state of Pennsylvania began requiring rabies vaccinations for cats. There appeared to be a correlation between the feline rabies vaccine and the increase in feline sarcomas.
This discovery created panic in the cat lover world, and to some extent, still does to this day. However, what many cat lovers don’t know is that these sarcomas are quite rare and only occur in 1-2 out of every 10,000 cat vaccinations. Furthermore, a Task Force continues to follow up on all reports of cat vaccine sarcomas. They issue regular reports to help your veterinarian choose the least inflammatory vaccines possible.
The Task Force has also helped to identify how to best manage the very rare occurrences of these cancerous tumors as the result of feline vaccinations. Because we now understand more about the nature of these tumors, careful guidelines have been put in place to ease the process of removing a tumor, should one occur, and significantly reduce the risk of any cat dying as a result.
Manufacturers of vaccines have also worked diligently to improve their vaccines and remove what was found to be some of the offending substances. Vaccines today are much safer and I personally have seen a drastic decrease in the number of localized vaccine reactions in my practice.
Without getting too technical, the three main cat vaccines - FVRCP-C, FeLV, and Rabies - are all given in very specific sites on the cat’s body. The FeLV vaccine should be given in the cat’s lower left hind leg, Rabies in the lower right hind leg, and FVRCP-C over the right shoulder. Cancerous tumors that develop in these areas are easier to remove surgically than in other locations of the body. And, in the unlikely event a sarcoma develops that cannot be surgically removed from the “higher-risk” vaccines given in the hind legs, amputation is easier and can save the cat’s life.
These standardized vaccine sites also help us, as veterinarians, track any negative responses to vaccination and report specifically which vaccine was the cause.
Cat Vaccines in Summary
It is important to remember that all of the vaccines given to cats are done so for your cat’s protection from viruses and diseases that would otherwise still be killing cats today. Continued vaccination prevents these diseases from re-emerging throughout the world.
Of course, how I practice veterinary medicine and how your veterinarian practices may differ, but it is important to know that the guidelines outlined above are simply that… Guidelines or recommendations for standard cat care.
Whenever you have a question or concern about your cat’s care, regardless of whether it’s about vaccines or any other cat care topic, you should address these openly with your veterinarian. Ultimately, what we all want is the best for your favorite feline!
Click below to see contributions from other visitors to this page...
Cat limping after getting feline vaccines
Vaccines in nursing cats: A danger to kittens?
Fibrosarcoma in my cat
Listless, Sleepy Behavior Following Cat Vaccinations
Feline Vaccines Schedule