There is a version of this article that just hands you a calendar. Six to eight weeks, first combo shot. Nine to twelve weeks, booster. Twelve to sixteen weeks, third round plus rabies. Done.
The calendar is worth having, and it is below. But it is the least interesting part of your kitten’s vaccine appointments, because the calendar is not what anyone gets wrong. Two other things are, and neither of them tends to get explained:
- Feline leukemia is now recommended for every kitten, including the one who will never see a blade of grass.
- Where the needle goes matters enormously, and if your vet is injecting your kitten low on a leg or in the tail, they are doing something deliberate and possibly life-saving.
Start there, then take the calendar.
The FeLV question, which is not really a question anymore
Feline leukemia virus is the one people are told to think about in terms of lifestyle. Does the kitten go outside? Is there a housemate who does? If no to both, skip it.
That framing is out of date. Current AAHA/AAFP guidance recommends FeLV vaccination for every cat under one year of age, regardless of whether they ever go outdoors.
The reasoning is unglamorous and correct. Kittens are more susceptible to FeLV than adult cats are, and a kitten’s future is not knowable at twelve weeks. The “strictly indoor” cat escapes. The household adds a cat two years later. A foster arrives. And FeLV is not a disease you get to recover from: it is highly contagious between cats, it suppresses the immune system, and it can cause cancer. You are vaccinating against a life you cannot yet see.
After the first year, it genuinely does become a lifestyle call, and you should have that conversation with your vet then.
Where the needle goes
This is the part that will change how you watch the appointment.
Cats can develop a rare but aggressive tumor at an injection site. It is called feline injection-site sarcoma, and it is locally invasive and hard to remove with clean margins.
The veterinary response has been elegant and slightly brutal in its logic: if you cannot eliminate the risk, put the injection somewhere you could amputate.
That is why the guidelines direct vaccines into the lower distal limbs or the tail. Distal-limb injections go below the elbow or below the stifle. Tail injections go in the distal third of the tail. The old practice of injecting between the shoulder blades was comfortable for everyone and disastrous if a sarcoma formed there, because the scruff sits on top of the spine and the ribs and there is nowhere to cut to.
Since the shift, tumors have moved down to the limbs, where surgery is actually survivable.
So: your vet is not being fussy. If your kitten is getting stuck in a back leg and you were expecting the scruff, that is the standard of care, and it is a good sign.
The core vaccines: every kitten, everywhere
These four are not negotiable, regardless of where the kitten lives, whether the mother was vaccinated, or who else is in the house.
Feline herpesvirus (FHV-1). Ubiquitous, spreads easily cat to cat, and goes after two targets: the eyes and the airways above the lungs. Expect watery or gooey discharge from the nose and eyes, coughing, sneezing, and redness and swelling around the eyes. Kittens and cats with other conditions get hit hardest.
Feline calicivirus (FCV). Frequently found working alongside herpesvirus, producing the same respiratory and ocular misery, plus a signature of its own: painful mouth ulcers that leave a cat drooling and unwilling to eat.
Feline panleukopenia (FPV). You will hear it called “feline distemper” or “feline parvo.” Both names are wrong; it is its own disease. Like parvo, it targets rapidly dividing cells, which means it wrecks the gut and wipes out white blood cells in kittens. Vomiting, diarrhea, fever, and recurrent infection follow. This is the one that kills whole litters.
Rabies. Infects any mammal, humans included. Effectively 100 percent fatal once clinical. Cats usually get it from wildlife such as skunks or raccoons. Indoor kitten? Vaccinate anyway.
The lifestyle vaccines
Your vet decides on these based on your kitten’s actual and probable exposure.
Feline leukemia virus (FeLV). See above. Core for the first year now; a lifestyle decision after that.
Feline immunodeficiency virus (FIV). Attacks the immune system much as HIV does in people, leaving a cat cycling through infections. There is no vaccine available in the US or Canada. One existed and was withdrawn, largely because it caused vaccinated cats to test positive on standard FIV antibody tests, sometimes for more than seven years, which made it impossible to tell a protected cat from an infected one. Prevention is entirely behavioral: keep your cat out of fights and away from bites.
Bordetella. Yes, cats can get kennel cough; it is not exclusively a dog problem. Infection shows up as lethargy, a fever, a runny nose, and a hacking cough. The vaccine is held back for cats who board or get groomed on a regular basis, which is to say cats who spend time crammed in among strangers.
Chlamydia (Chlamydophila felis). Produces the familiar sneezing, runny eyes, and runny nose. It is not part of the routine schedule. It comes out during an outbreak, to keep it from spreading, or for a cat whose life involves constant contact with other cats.
The schedule
Six to eight weeks. Nothing before six weeks: the antibodies a kitten got from its mother will still be circulating and will simply neutralize the vaccine. In this window, the first combination shot covering FCV, FHV-1, and FPV.
Nine to twelve weeks. Second round of the FCV/FHV-1/FPV combo. Your vet will likely start the FeLV series here too. And if your kitten missed the first window entirely, it is not too late; you just start now.
Twelve to sixteen weeks. The third FCV/FHV-1/FPV shot, if they have had two. The second FeLV booster. And rabies.
After that. Once a kitten has completed three rounds of the core combo, with the last at sixteen weeks, no booster is due for a year. From then on, the interval for an adult cat runs anywhere from annual to triennial, set by which vaccine it is and by how the cat actually lives.
Afterward
Kittens run on a loop of frantic energy and hard naps. Vaccines briefly flatten the energy half of that. Expect a sleepier, less playful kitten, a tender spot where the injection went in, and possibly a mild fever that lasts a day or so. Give them quiet and attention.
Escalate if your kitten is profoundly lethargic, refusing food, or running a high fever. That is not the expected reaction.
While you are at it, note where the shot went. If a firm lump appears at an injection site and it is still there after a few weeks, is bigger than a pea, or is growing, get it looked at. That is the reason the injection is in the leg.
Cost
It varies by where you live and which vaccine is being given, but budget roughly $50 to $200 per visit. Low-cost clinics and shelter vaccine days are widespread and legitimate; the vaccine in a $30 shot is the same vaccine.
What’s new since this was written
Two changes are worth knowing about.
The first is the FeLV shift covered above. If your vet is recommending feline leukemia for an indoor-only kitten and you were about to decline, that is not upselling. It is current guidance.
The second is quieter but more useful day to day: the injection-site protocol has visibly changed where tumors form. By moving vaccines from the scruff to the distal limbs and the tail, the profession moved a rare cancer from a place where it was frequently a death sentence to a place where surgery can get all of it. It is one of the clearest examples in veterinary medicine of a procedural change, not a drug, saving lives.
Nothing about your kitten’s calendar changes because of it. Where you watch for lumps does.
References
- Stone, A.E.S., Brummet, G.O., Carozza, E.M., Kass, P.H., Petersen, E.P., Sykes, J., & Westman, M.E. “2020 AAHA/AAFP Feline Vaccination Guidelines.” Journal of Feline Medicine and Surgery, 2020. journals.sagepub.com
- American Animal Hospital Association. Update on Feline Injection-Site Sarcomas. aaha.org
- Cornell Feline Health Center. Feline Leukemia Virus. vet.cornell.edu
- Cornell Feline Health Center. Feline Immunodeficiency Virus (FIV). vet.cornell.edu
- American Veterinary Medical Association. Feline Panleukopenia. avma.org
- Cornell University Baker Institute for Animal Health. Feline Calicivirus. vet.cornell.edu
