Cat vaccines explained

Vaccines teach a cat's immune system to fight serious diseases before it meets them. Every cat should have the core vaccines, which protect against panleukopenia and two respiratory viruses, and rabies where the law or the risk requires it. Other vaccines depend on lifestyle. Your vet sets the schedule, which varies by age, risk, vaccine and place.

How vaccines work

A vaccine shows the immune system a harmless form or part of a germ. The body then builds defenses, so it can respond quickly if it meets the real germ. Vaccines do not give instant protection. They take days to weeks to work. Kittens also carry antibodies from their mother's milk, which can block a vaccine until they fade. This is why kittens need a series of shots, not one.

No vaccine is perfect, but vaccinated cats are far less likely to get sick, and if they do, the illness is usually milder.

Core vaccines

Core vaccines are recommended for all cats, whatever their lifestyle. They protect against diseases that are widespread, severe or both. See core vaccines.

The combination vaccine. The usual core vaccine is a combination shot, often called FVRCP. It protects against:

• Feline panleukopenia (feline distemper, caused by a parvovirus). A severe, often fatal illness, especially in kittens. See feline panleukopenia.
• Feline calicivirus. A common cause of sneezing, eye and mouth problems, and sometimes severe illness.
• Feline herpesvirus. A common cause of sneezing, eye discharge and eye problems that can flare for life.

The vaccine reduces the severity of the two respiratory viruses, but may not stop every infection.

Rabies. Rabies is a fatal disease that can spread to people. Where rabies exists, vaccination is a core vaccine, and in many places the law requires it. See rabies vaccine. Rules differ by country, state and region, including the age at first vaccination and how often boosters are due. Ask your vet what applies to you.

Non-core vaccines

These depend on your cat's risk. Ask your vet.

• Feline leukemia virus. Often recommended for kittens, and for cats that go outdoors, live with an infected cat or mix with unknown cats. See feline leukemia virus. Your vet may test a cat before vaccinating.
• Chlamydia, Bordetella and others. These may be considered in certain settings, such as cat colonies, shelters or boarding. Ask your vet if they suit your cat.
• Feline immunodeficiency virus. A vaccine has been sold in some regions but is not widely used, and it can complicate testing. Ask your vet.

When vaccines are given

Schedules vary. A typical pattern is:

• Kittens: a first core vaccine from about six to eight weeks of age, then repeated every two to four weeks until about sixteen weeks or older. The final dose in the series matters most.
• Rabies: given at a set age, often twelve weeks or older, depending on the product and the law.
• First booster: about a year after the kitten series.
• Adults: boosters at intervals set by your vet, often every one to three years for core vaccines, depending on the vaccine, the cat's risk and local rules.

Use the kitten schedule to plan visits, then confirm dates with your vet. A cat adopted with no history usually needs a fresh series. Timing depends on age, health and law, so ask your vet.

Tailoring to your cat

Think about:

• Age. Kittens and seniors are more vulnerable.
• Lifestyle. Outdoor cats, multi-cat homes, boarding and shows raise exposure.
• Health. Cats that are ill or on certain medicines may need a changed plan. A cat that is sick on the day of the visit may need to wait.
• Legal and travel needs. Rabies is often required by law, and for travel, boarding or insurance, you may need proof.
• Past reactions. Tell your vet if your cat has had a reaction.
• Antibody tests. A vaccine titer measures antibodies in the blood. Some owners ask about it instead of repeating a vaccine. It is not accepted everywhere and does not cover every vaccine, so ask your vet.

What to expect after a vaccine

Many cats are fine. Mild signs for a day or two can include:

• Sleepiness or a lower appetite.
• Slight soreness or a small lump at the injection site.
• Mild fever.
• Sneezing after some intranasal vaccines.

Call your vet if the signs are strong or last. See a vet at once for:

• Facial swelling, hives, vomiting, diarrhea, collapse or trouble breathing within hours. These can be an allergic reaction.
• A lump at the injection site that is growing or is still there after a few weeks. Rarely, tumors develop at injection sites in cats, so any persistent lump needs a vet's attention.

Vets often give vaccines in different locations on the body so that a lump can be traced. Ask your vet where it is given and what to watch for.

Common mistakes

• Skipping the final kitten dose.
• Assuming indoor cats do not need vaccines. Indoor cats can catch viruses carried on shoes and clothes, can escape, and may need rabies vaccination by law.
• Stopping vaccines for older cats without advice.
• Losing the records. Keep a copy of the vaccine card.
• Vaccinating a sick cat without asking the vet.
• Overlooking the legal side of rabies.
• Skipping the exam. A vaccine visit is also a health check.

When to call a vet or get help

Contact your vet before the visit if your cat is sick, has not eaten, has a fever, is pregnant or has a long-term condition. Contact your vet after the visit for lasting lethargy, a lump, or any sign that worries you. Go to an emergency clinic for swelling of the face, trouble breathing or collapse.

Call a vet at once if an unvaccinated kitten becomes limp, stops eating, vomits or has diarrhea, because panleukopenia can kill quickly.

Summary

• Core vaccines protect against panleukopenia, calicivirus and herpesvirus. Rabies is core where required.
• Kittens need a series every few weeks until about sixteen weeks.
• Adults need boosters at intervals your vet chooses.
• Non-core vaccines depend on lifestyle.
• Report swelling, breathing trouble or a lasting lump at once.