To vaccinate, or not to vaccinate?
Never before has the topic of vaccination been so hotly debated as it is right now, in both human and veterinary medicine. Not surprisingly, it’s also becoming a big source of stress for pet parents as they try to make the best decisions regarding vaccination and its role in the overall health of their pets.
There’s no question that over the last several decades, vaccines have helped save the lives of millions of animals, and in the case of diseases that can be passed from animals to humans (like rabies), they’ve saved the lives of countless people as well. Where things get tricky is knowing who to listen to when it comes to recommendations on which vaccines our pets really need, and how often they need them.
Despite all the good they do, no vaccine is completely without risk. Which begs the real question at hand: are we doing more harm than good by over-vaccinating our pets?
How Vaccination Works – And Why We Need It
A vaccine is simply a substance created in a lab from a known pathogen, which is usually a virus or bacteria. These pathogens are then altered, either by killing them or making them so weak that they can’t actually cause disease. The pathogens are combined with other ingredients, like preservatives and stabilizers, to create a vaccine dose.
When the vaccine is injected into the body (“vaccination”), it stimulates the body’s immune system to recognize the pathogen as a threat, then launch an attack to destroy it. It also causes the immune system to forever remember that particular pathogen, giving the body protection against future infections.

Since animals are not born with lifelong protective immunity, it has to be established. Before the use of vaccination, any animal who got sick and was lucky enough to recover from the illness instead of dying developed immunity against the disease. However, many animals did not survive these illnesses, especially deadly viral infections like distemper and parvovirus in dogs and panleukopenia in cats. Sadly, we still see outbreaks of these diseases all over the world every year – illnesses that could be prevented or made less serious through vaccination.
Vaccination Risks
Despite all the good things that vaccines accomplish, they are not without risks. Pets can develop adverse reactions to vaccines, including:
- Fever
- Loss of appetite
- Vomiting
- Redness, swelling, or hair loss around the injection site
- Lethargy
- Swelling of the face
- Joint soreness or stiffness
- Hives
Other, more severe, reactions have also been reported, including:
- Seizures
- Abscesses
- Weight loss
- Uveitis (an inflammation of the eye)
- Inflammation of the heart, thyroid, or kidneys
- Anaphylactic shock
- Death
Long-term use of vaccinations has also been linked to the development of autoimmune diseases (such as autoimmune hemolytic anemia), allergies, skin disease, and digestive issues. The FVRCP vaccine has been proven to cause kidney inflammation in cats, and there is evidence to suggest that a type of cancer called vaccine-related fibrosarcoma may be related to repeated vaccinations in cats.
The Vaccine Controversy
So why all the controversy over pet vaccination?
In the 1970’s, all veterinary vaccines (with the exception of rabies) were licensed by the USDA based on limited studies that were done within the first few months after vaccination. At the time, vaccine labels were produced that included the statement “Annual Revaccination Recommended”.
However, the problem was that no one knew for sure whether the duration of immunity provided by the vaccine was one year or one lifetime. Put simply, they guessed. So veterinarians began vaccinating yearly, even though human vaccination research at the time showed immunity from vaccines against disease in humans could last anywhere from several years up to a lifetime.
In the mid-1970’s, a veterinary immunologist named Dr. Ronald Schultz began to question the recommended vaccine schedules. He conducted his own research on thousands of dogs, and found that vaccines protected these dogs for much longer than a year – in some cases, protection lasted the dogs’ entire lifetimes.
In 1999, Dr. Schultz published Duration of Immunity to Canine Vaccines: What We Know and What We Don’t Know, which states that for most major diseases in dogs (except rabies), vaccines provide immunity for at least 7 years. He even went on to state that “Vaccines for diseases like distemper and canine parvovirus, once administered to adult animals, provide lifetime immunity.”

In 2011, the American Animal Hospital Association (AAHA) updated their Canine Vaccination Guidelines to read “revaccination every 3 years or more is considered protective”, and included the comment “Among healthy dogs, all commercially available [core] vaccines are expected to induce a sustained protective immune response lasting at least 5 years thereafter.”
Unfortunately, many veterinarians have been slow to embrace the change. It’s estimated that about half of all veterinarians are still administering annual vaccines, despite evidence indicating that continuously re-vaccinating dogs and cats over a long period of time is not only unnecessary, it can potentially put their health at risk.
Current Vaccines For Dogs And Cats
In order to make an informed decision about the safest vaccination plan for your pets, you need to be familiar with what vaccines are available and whether they are necessary (hint: many of them aren’t).
Think of vaccines as belonging to one of two groups: ones that are considered necessary and vital for the protection of your pets against potentially life-threatening diseases (“core vaccines”), and those that are optional, given on an as-needed basis, depending on risk (“non-core vaccines”).
Below are the core vaccines for dogs:
- Rabies
- Parvovirus
- Distemper
- Canine Hepatitis (Adenovirus)
Non-core vaccines for dogs:
- Bordetella (kennel cough)
- Leptospirosis
- Parainfluenza
- Coronavirus
- Lyme disease (borrelia)
- Giardia
Core vaccines for cats include:
- Rabies
- Panleukopenia (feline distemper)
- Feline Calicivirus
- Feline Herpesvirus (feline viral rhinotracheitis)
Non-core vaccines for cats are:
- Feline Leukemia (FeLV)
- FIV (Feline Immunodeficiency Virus)
- FIP (Feline Infectious Peritonitis)
- Chlamydia
- Ringworm
Keep in mind that rabies is the only vaccine required by law in many states. THERE IS NO ONE-SIZE-FITS-ALL PROTOCOL WHEN IT COMES TO VACCINATING YOUR PETS. This means that not only do you have the right to ask your veterinarian to work with you to develop a customized vaccination protocol that is safest for your pets, you should insist on it.
For example, many veterinarians include the Feline Leukemia (FeLV) vaccine as part of their annual vaccination plan for cats. However, FeLV is not highly contagious, and if your cat is indoors-only and never goes outside, and there are no other cats with FeLV in your household, her chance for exposure to FeLV is virtually nonexistent. Since the FeLV vaccine is the primary suspect in the development of vaccine-related fibrosarcoma in cats, the risk of giving this vaccine to a cat who has very little chance of exposure to the virus is simply not worth taking.
The Exceptions – Puppies And Kittens
The exception to the theory “less is more” when it comes to vaccines are puppies and kittens. Because these little guys have underdeveloped immune systems, they need more protection than adult animals. Therefore, to fully gain immunity, it’s suggested that they need an initial round of core vaccinations between 6 and 8 weeks of age, another between 9 and 11 weeks, and a third between 12 and 14 weeks of age (ideally, shots are spaced out to give 3-4 weeks between vaccinations).
Don’t vaccinate kittens and puppies too early. Many veterinary experts suggest that 8 weeks is the magic number for the first vaccination. Always keep puppies and kittens away from public places and other unknown animals until they have received their first vaccinations.
So How Do We Safely Vaccinate Our Pets?

The subject of vaccination is not an easy one to wrestle with! But here’s the point: the benefits of vaccination still outweigh the risks, if you take the time to do it right.
Here are some tips on the safest ways to vaccinate your pets.
- Don’t over-vaccinate. Work with your vet to develop a customized protocol for your pet, taking into account age, lifestyle, health status, and risk of exposure. Focus on the core vaccines first, and only consider non-core vaccines if there’s a proven need for them.
- Test your pet’s immunity; don’t automatically re-vaccinate. You can check to see if your adult pet still has protective antibodies against specific diseases from previous vaccinations by running a test called a “titer”, which involves a simple blood test. If the test shows that the antibodies are still there, chances are your pet can skip the booster.
- Avoid combination vaccines if you can. Combo shots can include up to 7 vaccines in one injection, which can be overwhelming for your pet’s immune system, especially if he or she already has health issues. They can also increase the risk of adverse reactions, especially in cats and small dogs. Ask for single vaccines, spaced several weeks apart, if possible.
- Always ask for a non-adjuvanted vaccine. Adjuvants are substances added to vaccines to purposely cause inflammation at the vaccine site in an attempt to stimulate and speed up the immune response. However, adjuvants have been linked to the development of vaccine-related cancers, especially in cats. Avoid these at all costs.
- Never vaccinate a sick or stressed pet. This includes pets with autoimmune disease, cancer, skin conditions like mange or ringworm infection, even pets who are suffering stress from moving. It puts additional stress on a pet’s already-compromised immune system and can lead to serious adverse reactions. Also, never allow your pet to be vaccinated right before, during, or after surgery.
- Make sure the vaccine is given in the right place, especially for cats. For years, vaccines in cats were given below the scruff of the neck, between the shoulder blades. However, the American Association of Feline Practitioners and the American Veterinary Medical Association now recommend giving cats vaccines in either a hind leg or in the tail. Since cats are more prone to developing vaccine-related cancerous tumors at the injection site, it is much easier to amputate a limb or tail to cure the cancer and potentially save the cat’s life.
- Learn to recognize adverse reactions. Insist that your veterinarian document any vaccine reactions in detail and have it included in your pet’s medical record. Make copies of your pet’s medical records and store them in a safe place so you have access to them in case anything ever happens to your veterinarian’s office.
- Have your pet vaccinated at the safest time, which is early in the morning, early in the week so you have access to your veterinary staff if something should happen. If possible, you can wait in your car or a waiting area in the vet’s office for an hour or so after vaccines are given to ensure your pet does not have a severe reaction to the vaccine. Better to be safe than sorry.
- Never administer vaccines yourself. Although some vaccines can be purchased online, it’s always best to have them administered by a veterinarian. He or she will have vaccines that have been stored and shipped correctly and are not expired.
- Don’t let anyone intimidate you into giving unnecessary vaccinations. This includes groomers, boarding kennels, even veterinarians. If your groomer or boarding kennel will not accept titer test results as proof of immunity, consider going elsewhere.
Vaccinations: A Powerful Tool When Used The Right Way
When talking about vaccination, it’s important to remember the indisputable fact that vaccines save lives. It was Dr. Ronald Schultz himself who said, “Vaccines remain the single most important preventive medicine that we have available to protect our pets.”
However, vaccines need to be used in the safest way possible, and this includes making sure that every decision we make when it comes to vaccinating our pets is built around two concepts: weighing benefit vs. risk, and creating a customized vaccination protocol that is tailored to each individual pet. I vaccinate my own pets based on their age, health, and risk factors, and this is one area where I strongly recommend doing your homework and not being afraid to stand up and challenge anyone who recommends vaccinating more often than necessary. You have the absolute right to do that, and your pets are depending on you.
What are your thoughts about vaccination? Does your veterinarian still recommend annual vaccines for your pets? Please share your thoughts with us in the comments below!
Fantastic post about vaccinations. I’m very conservative about vaccinations and thankfully my vet is even more conservative. I believe that the current protocol is too much for dogs and cats.
Thanks, Kimberly! When I started researching the topic in detail, I was really surprised to learn that some of those vaccines can confer lifelong immunity in adult pets. When I was still in small animal practice, I distinctly remember one of the vets saying that many veterinarians use the annual vaccination protocol to make sure that clients bring their pets in every year for wellness exams (the theory being that owners wouldn’t do it otherwise). Knowing what we know now about the risks of over-vaccination, the irony of putting pets at risk just to make sure they came in every year for their annual health screens did not escape me! 🙁
” Since cats are more prone to developing vaccine-related cancerous tumors at the injection site, it is much easier to amputate a limb or tail to cure the cancer and potentially save the cat’s life.”…… Thats very scary !!!!
Mine get the CVR shot once a year BUT I think after this article I must talk to my Vet !!!
Thank you Camille xxx
I know, it sounds very drastic! But since fibrosarcomas in cats are so invasive (they have to be surgically removed and it’s very hard to remove it all), the reasoning is that it’s better to lose one part of the body than the cat’s life. And glad to hear you’re going to talk to your vet…it’s still important to get an annual exam for your kitties to make sure they’re healthy, but research shows they definitely don’t need the vaccinations every year. Good luck! 🙂
Great article. I couldn’t agree more with the statement that there’s no one sized fits all schedule that’s right for all pets. I hope more people will be encouraged to keep their core vaccinations up to date and be open to discussing the other ones with their veterinarian. Not only does your dogs lifestyle make a difference when it comes to deciding, but there’s regional considerations as well (such as tick prevalence/time spent outdoors for Lyme).
Absolutely. There are so many specialized vaccines out there (Lyme, Giardia, FIP, Ringworm), despite the fact that the risk of exposure to these illnesses for the average pet is slim to none. And some vaccines (like Bordetella for kennel cough) have been shown to be not very effective at preventing what they are supposed to prevent. Unfortunately, I think many pet parents believe (like I did many years ago) that more vaccines = safer, which sadly is not the case.
Thank you so much for such a well-written article, Camille. I’m planning on asking for the titer test next spring since Haley had a pretty severe allergic reaction the last time she had vaccinations. She had a rabies and annual combo shot at the same time, so I’m not sure which one caused the problem.
I get particularly annoyed at the kennel cough vaccines, which are required anytime a dog has a surgery or is boarded at our vet. We boarded Haley for the first time earlier this year and of course she had the kennel cough vaccine, but she came home with a case a kennel cough. Luckily, it was a mild case and cleared up quickly.
The tricky part of the vaccination debate is the fact that vets rely on them for a decent portion of their income. Thanks for explaining so many important points here!
Thanks, Elaine! Titer tests are a wonderful resource… many people think they are expensive, but depending on the vet practice, they can cost as little as $50 – which is about the cost of having the vaccination anyway! And regarding the bordella vaccine, there are so many strains of kennel cough out there that it’s impossible to protect against all of them, which is likely why Haley still came down with it. And when you think about the fact that kennel cough is simply a viral infection that’s self-limiting, like a human cold (dogs will recover on their own, with or without treatment), the vaccine really is of little to no benefit when you weigh it against the risk. Thankfully, many vets are no longer recommending it, but the boarding kennels, doggie daycares, and groomers now need to catch up!
It’s great that you mention that you can help keep your pet safe from diseases by having them vaccinated. I want my new kitten to remain as healthy as possible, so I’m thinking about taking her to a veterinarian this month to get vaccinated. I’m going to look for a good veterinarian in my area that offers pet vaccination services.
Thank you for elaborating on how vaccines can help to immunize your pet against certain diseases. My girlfriend and I want to make sure our new puppy has a long and healthy life, so we should probably take him to an animal hospital to get vaccinated this month. I’m going to see if there’s a good animal hospital in our area that can vaccinate our dog for us.