Is Your Cat at Risk? Why Vaccines are Critical for Feline Health


It is absolutely necessary to get vaccines for indoor cats. While indoor cats are less likely to be exposed to some contagious diseases than outdoor cats, vaccines help protect cats against many dangerous and potentially fatal illnesses they can still contract indoors. Vaccines work by stimulating the immune system to produce antibodies against specific infectious agents, training it to fight off disease. Unvaccinated cats are at risk for a variety of diseases which can potentially lead to death. Core vaccines help protect against the most common and serious feline illnesses such as panleukopenia, calicivirus, herpesvirus, and rabies. Even though your cat may live entirely indoors, vaccines can prevent the spread of illness in multi-cat households and protect your cat’s health if they accidentally escape outside. Vaccinating your cat is an essential part of responsible pet ownership and preventative care.

Core Cat Vaccines

There are four core vaccines that are absolutely essential for all cats according to the American Association of Feline Practitioners (AAFP). These include vaccines for rabies, panleukopenia, calicivirus, and herpesvirus (rhinotracheitis).

The rabies vaccine is required by law in most states. Rabies is fatal once symptoms appear, so vaccination is crucial. The killed virus vaccine provides minimum protection for one year (Bettervet, 2022).

Panleukopenia, also known as feline distemper, is a severe and highly contagious viral disease that attacks the intestinal tract and bone marrow. The modified live virus panleukopenia vaccine provides a minimum of three years of protection (East Valley Animal, 2021).

Calicivirus causes oral ulcers and upper respiratory infection. The modified live vaccine protects for 1-3 years against disease from common strains (Bettervet, 2022).

Feline herpesvirus infection leads to upper respiratory infection, eye infections, and rarely neonatal death. The modified live rhinotracheitis vaccine protects for 1-3 years (East Valley Animal, 2021).

Non-core vaccines

In addition to the core vaccines, there are some other non-core vaccines that may be recommended for cats with certain lifestyles or risk factors. According to the American Association of Feline Practitioners (AAFP), the most common non-core vaccines for cats are:

Feline leukemia virus (FeLV) vaccine: The FeLV vaccine is recommended for cats that go outdoors unsupervised and have exposure to other cats. FeLV is a contagious virus that suppresses the immune system and can lead to cancer and other illnesses. Transmission most often occurs through direct contact like mutual grooming, sharing food bowls, or bites from infected cats. According to the SplootVets article The Ultimate Pet Parent’s Guide to Cat Vaccines, the FeLV vaccine is 78% effective at preventing infection.

Feline immunodeficiency virus (FIV) vaccine: FIV is similar to FeLV in that it weakens the immune system, making cats more prone to infections and cancers. It spreads through deep bite wounds, so free-roaming outdoor cats or homes with multiple cats that fight are most at risk. There is an FIV vaccine available that may help reduce infection risk in higher risk cats.

These non-core vaccines provide an extra layer of protection for cats with greater exposure to contagious diseases. However, there can be some risks and side effects, so it’s important to discuss your cat’s lifestyle and risk factors with your vet to determine if they are recommended. The core vaccines should form the foundation of protection for most house cats.

Vaccine schedule

The vaccine schedule for kittens is different than the schedule for adult cats. According to PetMD, kittens should receive their first round of core vaccines between 6-8 weeks of age. These include feline herpesvirus (FHV), calicivirus (FCV), and panleukopenia virus (FPV), which are covered in a combination FVRCP vaccine. Kittens also receive their first FeLV vaccine at this age. At 10-12 weeks, kittens receive a second dose of FVRCP and FeLV vaccines. A third FVRCP dose is given at 14-16 weeks.

For adult cats, East Dallas Veterinary Clinic recommends an annual FVRCP booster and a FeLV booster every 1-3 years depending on risk factors. Adult cats may receive additional non-core vaccines like feline leukemia (FeLV) or rabies based on lifestyle factors. Indoor cats typically only require the FVRCP booster annually once they reach adulthood. Outdoor cats or cats with potential exposure to stray/feral cats may receive more frequent boosters. Owners should consult their veterinarian to determine the optimal vaccine schedule for their cat based on age, health status, and lifestyle factors.

Risks of not vaccinating

Not vaccinating cats properly can expose them to a number of dangerous and potentially fatal diseases, including:

  • Rabies – Rabies is a fatal viral disease that affects the central nervous system. It can be spread through bites and exposure to saliva from infected animals. Rabies is almost always fatal once clinical signs appear.
  • Feline panleukopenia (distemper) – A highly contagious and life-threatening disease that causes fever, lethargy, vomiting, and diarrhea. It has a high mortality rate in kittens.
  • Feline leukemia virus (FeLV) – A retrovirus that suppresses the immune system, making cats prone to secondary infections, anemia, and cancer. It is fatal in most cats.
  • Feline immunodeficiency virus (FIV) – A retrovirus that weakens the immune system over time. It makes cats susceptible to various secondary infections and diseases.
  • Feline infectious peritonitis (FIP) – Caused by a mutation of the feline coronavirus. It is fatal in cats and kittens, causing systemic inflammatory disease.
  • Upper respiratory infections – Common viral and bacterial infections of the upper respiratory tract, including feline herpesvirus and calicivirus. Can be chronic and fatal in kittens.

Vaccinating cats according to recommended schedules protects them from contracting these harmful diseases that could cut their lives tragically short. Consult with your veterinarian to determine the right vaccination plan for your cat.

Side Effects

Like any medication or vaccine, there’s a possibility of side effects occurring after a cat receives their routine vaccinations. Some common side effects include:

  • Soreness or swelling at the injection site
  • Mild fever
  • Decreased appetite
  • Lethargy or tiredness
  • Vomiting or diarrhea

According to research (, most side effects are mild and resolve within 24-48 hours on their own. More severe reactions like facial swelling or difficulty breathing are possible but quite rare.

To help minimize side effects, have your cat examined by a vet before vaccinations to ensure they are healthy. You can also ask for certain vaccines to be administered separately, instead of in a combination shot. Make sure to monitor your cat after vaccinations and contact your vet if any concerning or prolonged symptoms arise.


There are some cases where veterinarians may recommend skipping or delaying certain vaccines for cats, especially for ill or senior felines. According to KeepingItPawsome, exemptions may be made for cats with illnesses like feline leukemia virus or feline immunodeficiency virus, as vaccines could potentially worsen their condition. Kittens or cats who are severely malnourished or ill may need to wait until their health improves before getting vaccinated.

For senior cats, vets may suggest only administering the core vaccines after a certain age. This is because older cats are more likely to experience side effects from vaccines or already have immunity from earlier vaccinations. Discuss with your vet about which vaccines are necessary for your senior cat based on their lifestyle and medical history.

Pregnant cats should not receive any vaccines aside from rabies, if legally required. Otherwise, vaccination is generally avoided from 4 weeks prior to breeding until 4 weeks after giving birth to avoid potential harm to the fetuses or newborn kittens.

Overall, there are valid medical reasons why some cats may be exempt from specific vaccines or doses. Have an open discussion with your veterinarian about what’s appropriate for your individual cat’s health status and risks.


The cost of cat vaccines can vary depending on your location, the specific vaccines given, and whether you go to a private vet clinic or a subsidized clinic. According to MarketWatch, the average cost per vaccine ranges from $15-38 USD. Core vaccines like rabies and distemper tend to be on the lower end, while non-core vaccines like feline leukemia can be more expensive.

In Malaysia, Oyen estimates the annual cost for core cat vaccines to be RM40-100 (around $10-25 USD). This covers the basic distemper, hepatitis, parvo, and rabies vaccines. Additional non-core vaccines will add to the total cost.

When budgeting for your cat’s vaccines, expect to spend around $100-150 USD annually for the core vaccines, with non-core vaccines adding $15-38 each. The first kitten series may cost more since multiple doses are given. But routine annual boosters are quite affordable, making vaccines a wise investment to protect your cat’s health.

Making Appointments

Making appointments to get your cat vaccinated is an important part of responsible pet ownership. Here are some tips for scheduling vet appointments for cat vaccines:

Look ahead on your calendar and schedule annual vaccine boosters well in advance, such as 3-4 months ahead of time. This helps ensure you get an appointment that fits your schedule (source: Petco).

When scheduling appointments, let the vet clinic know which specific vaccines your cat needs so they can plan accordingly. Have your cat’s vaccine records on hand for reference (source: What To Expect: A Vaccination Appointment).

Ask about any vaccine package discounts the clinic may offer if you schedule multiple vaccines at once, such as the 5-in-1 or 4-in-1 combination shots (source: VCA Animal Hospitals).

Inquire about the total costs for the recommended vaccines so you can be prepared to pay for them. Many clinics require payment at the time of service.

Arrive early for appointments so you can fill out any necessary paperwork before the vet sees your cat.

Follow your vet’s guidance about whether your cat needs to fast before the appointment.

Bring your cat in a secure carrier and keep their vaccine records handy so the vet can review and update them.


In conclusion, keeping up with proper vaccinations is crucial for protecting cats against dangerous and potentially fatal diseases ( Core vaccines, like those for feline herpesvirus, calicivirus, and panleukopenia virus, provide critical immunity against common viruses that can make cats severely ill ( While adverse reactions are rare, the risks posed by these preventable diseases far outweigh any minimal side effects. Working closely with your veterinarian to maintain the recommended vaccination schedule will ensure your cat remains happy and healthy for years to come. Though exemptions are available in some cases, vaccines should not be avoided without first having an informed discussion of the risks. By keeping your cat up-to-date on his shots, you are taking important steps to protect him and giving him the best chance at a long and fulfilling life.

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