Education Center

Why Do Cats Need Shots? protect your cat from feline diseases

To help your cat stay healthy and happy, you should both visit your veterinarian at least once every year. This annual visit is an opportunity for your cat to have a thorough physical examination.

However, the most important service provided by your veterinarian during this visit is the one your cat likes the least…those injections.

With a quick series of tests and vaccinations, your veterinarian protects your cat against serious, often fatal, feline diseases. As a concerned cat owner, you should know what these procedures provide for your cat. Your feline family member may be with you for 15 to 20 years (with regular health care and a safe, indoor lifestyle). You want every year to be a healthy one!

NOTE: If your cat does become ill, the cat may hide the symptoms…sometimes by actually hiding from you (under or behind a piece of furniture, for example). If you aren’t aware that a problem exists and the cat isn’t seen by a veterinarian, even the most simple illness can become serious.

Know your cat’s habits, and be alert to any sudden change – especially eating habits, discharge from the eyes or nose, litter box behavior, or unusual hiding – and call your veterinarian immediately.

How do vaccinations work to protect my cat?

Vaccines for pets work like vaccines for humans.

A vaccination against a certain virus is actually a small, slightly altered dose of the virus itself. Your cat’s body reacts to the vaccination by building up antibodies.
These antibodies circulate in the bloodstream and protect your cat against a real infection. These antibodies weaken and die after time. Therefore, an annual revaccination, or “booster” shot, is sometimes necessary every year to continue the protection.

With these injections, your veterinarian can help you and your cat avoid the pain, anxiety, and cost of many serious feline infections. And for some of these diseases, there is no treatment – only the prevention offered by vaccinations.
Vaccinations are necessary, inexpensive insurance. Even cats who live indoors can be exposed to infectious diseases and should be vaccinated regularly.

Is there a “basic” vaccination?

The primary vaccination your cat receives every year is a booster of the “kitten series” given when your cat was about six weeks old. This injection, known as FVRCP, is given to young kittens in a series of three or four visits, spaced at three-week intervals. An adult cat needs the single FVRCP booster every year.

The FVRCP protects your cat against feline distemper (see below), as well as the three most common upper respiratory infections: Chlamydia, Calici, and Rhinotracheitis.

EFFECT: Feline respiratory diseases are similar to a human cold or flu, causing sneezing, coughing, runny nose and eyes, fatigue, and general misery. Respiratory infections are highly contagious and can become chronic (permanent).

CAUSE: Respiratory diseases are spread through direct or indirect contact with a infected cat. Sick cats don’t use tissues; they clean themselves with their paws and then spread the infection as they walk.

You should take the same precautions to prevent the spread of feline respiratory disease that you use to prevent spreading a cold among people – wash or disinfect all surfaces (including human hands) which may have been contaminated by the body fluids of the infected cat.

PREVENTION: However, a feline upper respiratory infection is much more serious than a human cold and lowers a sick cat’s resistance to other diseases. Humans have no vaccine against the common cold; cats do have the FVRCP.

I didn’t know that cats could get distemper. Can my cat catch distemper from my dog?

Feline distemper and canine distemper are not the same disease; cats and dogs cannot contract distemper from each other. Feline distemper (also known as panleukopenia or feline infectious enteritis) is a serious, potentially fatal, disease.

EFFECT: A cat with distemper suffers from diarrhea, vomiting, depression, and loss of appetite. The disease also destroys the white blood cells, leaving the cat with no immunity to other infections.

Feline distemper is highly contagious and very common and kills nine out of ten cats and kittens that contract the disease. It is particularly dangerous for young kittens.

CAUSE: The virus is often passed to unborn or nursing kittens directly from the mother cat. Feline distemper is also spread through the infected cat’s body fluids and into the cat’s litter box.

PREVENTION: This stubborn virus can live for months in almost any environment; therefore, the chances are very high that your cat will be exposed at some time to feline distemper. This is the most important reason for your cat to be protected with the FVRCP vaccination.

Do I need to vaccinate my cat against Feline Leukemia (FeLV)?

Yes. In the last decade, veterinary science has found effective prevention to be used against this cat-killer. Feline Leukemia (FeLV) is caused by a virus and takes different forms in infected cats.


EFFECT: One of the most frightening aspects of FeLV is the difficulty in identifying the infection from early symptoms. Loss of weight and condition, depression, and other general signs of illness may be the only signals.

The symptoms shown are usually those of other illnesses, which would normally be easy to combat. However, the immune system of a cat infected with FeLV cannot properly provide the normal resistance and protection against common infections.

A FeLV infected cat may develop tumors or cancer of the blood cells, or may die from complications of other feline diseases. Few cats which test positive for FeLV live more than three years past the original infection.

CAUSE: Feline leukemia can be transmitted from an infected mother cat to her kittens (before or after birth), or through contact with any infected cat’s saliva, urine, feces, or blood. Such contact may be made directly, through licking or biting.

The virus is easily transmitted indirectly as well. When an FeLV cat sneezes, or licks itself, another cat can become infected by walking across the area where the infected cat has just been sitting, lying, or walking. The virus can also be transmitted through shared food or water dishes or litter boxes. Even a flea can carry infected blood from one cat to another.

It is unlikely that feline leukemia can be carried from cat to cat on a human’s skin, clothing, or shoes. The virus does not live long on dry surfaces – no more than a few minutes. In a moist environment, it can live two or three days.

The FeLV virus is easily killed by most household disinfectant cleansers and soaps. (As always, use caution when using chemicals around your cat.)

Once a cat has contracted the FeLV virus, there are three levels of infection:

  • An actively infected cat will actually show signs of feline leukemia.
  • A transient infected cat will test positive for the disease but will appear to be healthy. In a few weeks the cat can develop immunity to the FeLV virus and so will test negative when retested at that time.
  • A latent carrier remains healthy but still spreads the FeLV virus and will continue to test positive. In most cases, a latent carrier will eventually become ill if placed under stressful conditions.

PREVENTION: Feline leukemia has no proven treatment. However, the disease can usually be prevented by testing cats and kittens at nine to twelve weeks old with a simple blood test. Results are available at most veterinary clinics within thirty minutes.

If the test is negative, vaccinations should begin as soon as possible. The first time your cat is vaccinated for feline leukemia, the vaccine will be given twice within a three to four week interval. (The annual booster is a single injection.)

A cat who tests positive for feline leukemia should be isolated from other cats if at all possible, even if there are no symptoms at that time. (The positive cat does not need to be vaccinated because the vaccine can only prevent, not cure.)

What is “feline AIDS”? How can I protect my cat?

Both of the deadly cat diseases which involve failure of the immune system – Feline Leukemia (FeLV) and Feline Immunodeficiency Virus (FIV or “feline AIDS”) – are surrounded by myths and misunderstandings. It is important that you understand the facts about the two diseases and how your cat can be protected against them.

Feline Immunodeficiency Virus (FIV) is often mistakenly referred to as “feline AIDS.”

FIV and FeLV are similar to the HIV/AIDS viruses in humans, but are strictly isolated to cats.

Cats cannot catch AIDS; humans cannot catch FIV or FeLV.

EFFECT: The FIV virus shuts down the immune system of an infected cat with damage and resulting illness similar to that of feline leukemia.

CAUSE: FIV is less contagious than FeLV but is spread through similar means, primarily blood and saliva (often from bites).

PREVENTION: A cat cannot develop an immunity to FIV, so the infection is lifelong. Research veterinarians are working to develop a safe, effective vaccine against FIV, but there is no preventative available at the present time. The spread of the disease can be reduced by testing all cats for FIV and by isolating infected cats.

Diagnosis is based on a positive blood test, and many veterinarians now use an FIV test that is combined with testing for FeLV. Ask your veterinarian about appropriate testing (and any future vaccinations) for your cat.

Does my cat need a rabies vaccination?

An annual rabies vaccination is required by law for every cat and kitten, beginning when the kitten is four months old. Even if your cat lives indoors, you and your cat need protection against rabies.

EFFECT: Rabies is a painful, fatal infection of the nervous system which affects warm-blooded animals…including humans. An infected animal will be stiff or paralyzed and will not be able to swallow properly (causing the heavy drooling we associate with a “mad,” or rabid, dog).

The final stage of the disease causes intense sensitivity to noise and movement which causes the animal to behave abnormally out of pain. A sick animal, which would normally avoid pets and people, may approach and attack anything (or anyone) that moves.

CAUSE: The infection is spread through the saliva of an infected animal (usually a fox, skunk, raccoon, bat, cat, or dog), so your cat can be exposed to rabies by a bite or scratch. So can you!

PREVENTION: There is no cure for an unvaccinated cat infected by rabies; a vaccination is the only protection for you and your cat against this serious disease. And it’s the law!

This information is part of the Atlanta Humane Society’s SmartHeart Educational Series.

The AHS depends on friends to provide funding for our services and programs of animal aid, support for individuals with animal related problems, and community animal issues.

The Atlanta Humane Society and Society For Prevention Of Cruelty To Animals, Inc. is a private nonprofit organization for the purpose of preventing cruelty, relieving suffering, and providing humane treatment of animals. The Society’s mission is to eliminate causes of animal suffering with an emphasis on education and the human/animal bond.