How far apart are kitten distemper shots?

When getting a new kitten, one of the most important things is making sure they are properly vaccinated against common feline diseases. Among the core kitten shots is the distemper vaccine. But how far apart do kittens need their distemper shots? Let’s take a closer look.

The Basics of Kitten Shots

Kittens are born without much natural immunity against diseases. They receive some antibodies from their mother’s milk that protect them for the first few weeks of life. But after that, kittens need vaccines to help their immune system fight off illnesses.

There are several “core” vaccines kittens need:

  • Feline panleukopenia virus (FPV) – also called feline distemper
  • Feline viral rhinotracheitis (FVR)
  • Calicivirus (FCV)
  • Rabies

These vaccines are called “core” because they protect against severe, life-threatening diseases. Other non-core vaccines may be recommended by your vet depending on your cat’s lifestyle and risks.

Kittens need a series of vaccinations to become fully immunized. The initial series is generally given between 6-16 weeks old, with a booster 1 year later. After that, core vaccines are boostered every 1-3 years depending on your vet’s protocol.

When to Start Kitten Shots

The general guideline is to start vaccinations at 6-8 weeks of age. Maternal antibodies passed to kittens through nursing will interfere with vaccination if given too early. By 6-8 weeks, maternal antibody levels have dropped enough for vaccines to be effective.

Some vets may start the initial series as early as 4 weeks for kittens at high risk of disease. Kittens in shelters or multi-cat homes are at greater risk and may need earlier protection.

Kitten Shot Schedule

For the initial kitten shot series, there are two basic protocols vets commonly follow:

2-Dose Series

  • 1st dose at 8 weeks old
  • 2nd dose at 12 weeks old

3-Dose Series

  • 1st dose at 6 weeks old
  • 2nd dose at 9 weeks old
  • 3rd dose at 12-16 weeks old

With either protocol, the 2nd (or 3rd) dose is given at 12-16 weeks or older. Giving the final dose at 16 weeks allows maximum response from the kitten’s immune system.

Booster shots are given 1 year after the initial series, then typically every 1-3 years depending on your vet’s recommendations.

Why Kittens Need Multiple Doses

Giving a single dose of vaccine does not provide the best protection against disease. Kittens need at least 2 doses separated by 2-4 weeks to mount an effective immune response. Even with two doses, immunity may not be complete until a week or more after the second dose.

Some maternal antibodies may still be present at 6-8 weeks when vaccination starts. While not high enough to prevent immunization, these antibodies may blunt the response to the first vaccine. A second dose helps strengthen immunity. That is why a 2-dose initial series is standard.

Are Annual Boosters Needed?

For kittens, an initial series and 1 year booster are essential. But after that, some researchers argue that annual revaccination may not be necessary for every cat. Once an adult cat is fully immunized after their kitten shots, they are likely protected for several years at minimum.

However, annual boosters are still commonly recommended since it is difficult to know when immunity may start fading in an individual. An annual booster schedule ensures continuous protection without need for antibody testing.

Your vet may recommend antibody testing to determine if boosters are needed less often in low-risk adult cats. But for kittens, stick closely to the initial series and 1 year booster schedule recommended by your vet.

Importance of Complete Kitten Shots

Giving all recommended vaccines on schedule is critical to proper immunity. Below are some key reasons why:

  • Maternal antibodies interfere early – Maternal antibodies block effectiveness before 8 weeks, so early vaccines may be wasted.
  • Two doses are better than one – The first dose primes the immune response, the second strengthens it.
  • Timing matters – Kittens need the last dose at 12 weeks or older for optimal response.
  • Diseases are severe – The feline “core” diseases can be very serious and even fatal.
  • Environmental factors – Shelters and multi-cat homes increase disease exposure risk.

Check with your veterinarian about the recommended schedule for your kitten. Be sure to complete the entire series on time for best protection.

Are Kitten Shots Safe?

Vaccines approved for use in kittens have undergone extensive safety testing and years of use showing them to be very safe overall. Still, as with any medication, there is always a small risk of side effects.

Common vaccine side effects in kittens may include:

  • Low-grade fever
  • Soreness at the injection site
  • Mild lethargy
  • Decreased appetite

These effects are usually mild and resolve within 24-48 hours. More severe allergic reactions are possible but very rare.

In general, the risks associated with vaccination are far outweighed by the benefits of preventing serious infectious diseases in kittens. Talk to your vet if you have any concerns.

Can Missed Doses Be Made Up?

If you miss a scheduled kitten shot, try to make it up as soon as possible. The goal is to complete the series within the 16 week optimal window for maximum immunity.

For example, if you miss the 9 week dose of a 3-dose series, your vet may recommend giving the second dose right away, then the final dose at 15-16 weeks.

Kittens who miss doses or fall behind on shots are left vulnerable to disease. At minimum, they need:

  • At least 2 doses 3-4 weeks apart
  • The final dose no earlier than 12 weeks old

Work with your vet to get your kitten back on track as soon as possible if doses are missed.

Are Annual Boosters Necessary?

For adult cats, there is some debate about whether annual boosters are needed for core vaccines. Some studies have shown immunity lasts at least 5 years after the kitten series and 1 year booster are complete.

However, since it’s difficult to predict when an individual cat’s immunity will wane, most vets still recommend annual boosters. This ensures consistent protection without need for antibody testing each year.

Discuss your adult cat’s lifestyle and risk factors with your vet to determine optimal booster frequency past 1 year. But completing the full kitten series followed by the 1 year booster is crucial no matter what.

Should Vaccines Be Given Together?

Giving more than one vaccine at the same visit is standard practice with kittens. Combination FVRCP products containing both feline distemper and respiratory disease vaccines are commonly used.

Studies have shown injectable vaccines can be given together without interference or increased risk of side effects. FeLV and rabies vaccines are often added to the FVRCP combo at the same visit.

However, intranasal vaccines like FHV-1 are recommended to be given alone. Your vet will ensure proper timing and administration of all needed kitten vaccines.

Are Homeopathic Options Effective?

There are no approved homeopathic, herbal, or nosode products that provide effective protection against feline distemper or the other core kittenhood diseases. These unproven products are not a substitute for conventional vaccines.

While homeopathic nosodes may claim to contain disease antigens, studies show they do not produce any real antibody response. There is also no proof they provide disease protection comparable to the immunity produced by standard vaccines.

For reliable disease prevention in kittens, conventional core vaccines given on schedule remain strongly recommended by veterinarians and health experts.

Why Are Boosters Needed if Immunity is “Permanent”?

In an individual cat, core vaccine immunity often lasts 5+ years and may be described as “permanent” or lifelong. But at a population level, duration of immunity varies between cats.

We can’t easily test each cat each year to see if immunity is still sufficient. Annual or triennial boosters are advised because while some cats likely still have immunity, others in the group may not.

Boosters keep a higher percentage of cats protected year after year vs only boosting those found to have low immunity. This maintains better disease protection in the overall feline population.

Is FeLV Vaccine Recommended for All Kittens?

FeLV vaccination is considered core for kittens by some vets, optional by others. Factors in the decision include:

  • Indoor vs outdoor cats – Indoor cats have less FeLV exposure risk
  • Multi-cat home – Higher risk if new cats are introduced
  • Geography – FeLV is more prevalent in some regions

Kittens adopted into homes with known FeLV-infected cats should always get the vaccine. Talk to your vet about whether routine FeLV vaccination is advised for your individual kitten.

Do Kittens Need Vaccines for Chlamydia, FIP, or FIV?

Vaccines for these diseases are considered non-core or optional because:

  • Disease risk varies by lifestyle and geography
  • Vaccine efficacy may be incomplete
  • Benefit vs risk ratio is less clear

There are currently no FIP vaccines approved in North America. Your vet may discuss use of an experimental vaccine in high-risk cases. But core vaccines remain most crucial for broadly protecting kitten health.

At What Age Can Rabies Vaccine Be Given?

The earliest age rabies vaccine is licensed for use in kittens is 12 weeks. However, some vets prefer waiting until 16 weeks or older to give the first rabies vaccine because:

  • Rabies vaccines tend to cause more injection site reactions
  • 12-16 weeks is when maternal immunity is significantly lower

There are nearly always legal requirements for rabies vaccination. Discuss timing with your vet to ensure compliance with local rabies laws.

Should Kittens Have Blood Tests Before Vaccination?

Pre-vaccination blood tests are not routinely recommended in healthy kittens. Testing will show maternal antibodies are present, but this is expected in kittens less than 8 weeks old.

Vaccines are engineered to elicit an immune response even if maternal antibodies are present. Unless a kitten has an underlying health condition, pre-vaccine blood tests are generally not needed.

What If a Kitten Is Over 16 Weeks Old and Unvaccinated?

Kittens over 16 weeks old who have not yet had any vaccines are past the optimal window for the initial kitten series. At this point, an abbreviated schedule can help get some protection as soon as possible:

  • Give one dose of FVRCP vaccine
  • Repeat 2-4 weeks later for second dose
  • Give a rabies vaccine at least 2 weeks after the second FVRCP
  • Boost all vaccines 1 year later

This gets the kitten started on the core vaccines quickly. Additional boosters will be needed at 1 year and beyond to ensure solid immunity.

Vaccination Schedule Summary for Late Vaccination Start

Age Vaccines
>16 weeks FVRCP #1
2-4 weeks after first dose FVRCP #2
At least 2 weeks after second dose Rabies vaccine
1 year after second FVRCP FVRCP and Rabies booster

While not an ideal start, this schedule helps provide some protection. Annual boosters will be important going forward.

Can a Kitten Be Vaccinated While Nursing?

Vaccinating kittens under 4 weeks of age while still nursing is not recommended. Maternal antibodies in milk can block vaccine response.

There are exceptions in some high-risk situations. Shelters may vaccinate feral kittens as young as 2 weeks if they are at very high risk and will be adopted immediately. But routine vaccination should start no earlier than 6 weeks.

Do Kittens Need Deworming?

Intestinal parasites are very common in kittens. Kittens should be dewormed starting at 2-3 weeks of age, repeated every 2-4 weeks until 12 weeks old.

Common dewormers for kittens are pyrantel pamoate and fenbendazole. The first treatments may not eliminate all worms, so repeat dosing is important.

Adult cats usually need annual fecal testing and deworming. But monthly preventives are recommended for kittens until at least 6 months old. Kittens are at much higher risk of parasite infections compared to adult cats.


Getting all recommended kitten shots correctly timed is vital to protecting your new pet’s health. The initial vaccine series starts as early as 6 weeks and includes at least 2 doses of FVRCP and rabies vaccine by 16 weeks old.

Booster vaccines continue at 1 year old, then every 1-3 years depending on your vet’s advice. Sticking closely to these veterinary guidelines provides the best disease protection during kittenhood and beyond.

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