Cat Vaccines

There are far fewer vaccines available to cats compared to dogs. We will discuss three of the most common vaccines given. Two of these are considered core vaccines, and the other one is specifically for at-risk cats.

Core Vaccines

The rabies vaccine is given to kittens between 12-16 weeks of age. The first vaccine is good for one year, and each booster is good for either one or three years thereafter depending on the label. This disease is the same in cats as we see in dogs. It is transmitted through the saliva of an affected animal and results in severe neurological disease leading to death.

This vaccine protects against three diseases, which include Feline Viral Rhinotracheitis (herpes), Calicivirus, and Panleukopenia (feline distemper). The first dose is given between 6-9 weeks of age followed by boosters every 3 weeks until 16 weeks of age. It is boostered again at one year and then every 3 years thereafter. Feline herpes and calicivirus both cause upper respiratory disease and eye or oral lesions. Feline panleukopenia is a severe, but very uncommon disease in cats today. It causes gastrointestinal and neurological disease.

Non-Core Vaccines

The FeLV vaccine is the most common non-core vaccine we consider for cats. It can be given to kittens or adults, but it must be boostered 3 weeks after. It is only given to cats who are outdoors and considered high risk. Cats should test negative for FeLV prior to receiving their first vaccination because if they test positive, there is no need for the vaccine. Read more about FeLV in cats here!

In the past there had been controversy regarding vaccines in cats due to the added adjuvant that was used to boost the immune response. Select cats developed injection site sarcomas (masses) from these vaccines. Now, vaccines have been developed that do not contain these adjuvants and are less controversial in veterinary medicine today. Your veterinarian will be happy to go over what vaccines he or she uses and any concerns you have at your cat’s first appointment.

What is the SNAP Combo Test for Cats?

Many of you have probably visited the veterinarian’s office where a SNAP combo test was recommended to check for infectious diseases in your cat or kitten. You may have wondered what this test is and why it is important. These tests are usually recommended in your kitten’s first year of life, but can be done at any time if you adopt an adult cat or if your cat becomes ill.

A SNAP combo test checks for Feline Leukemia Virus and Feline Immunodeficiency Virus, which are both lifelong diseases that cause immunosuppression. They are not overly common, but it is best to diagnose these diseases early on since they are contagious and can spread to other cats in the household.


Feline Leukemia Virus is considered a “friendly cat” disease because it is most commonly transmitted through saliva when cats are grooming each other or drinking out of the same bowl. It can also be spread through bodily fluids, such as urine, or from the mother during nursing. It is most common in younger cats but can occur in any age. This virus infects the bone marrow resulting in immunosuppression and anemia. Cats infected have a higher risk of developing lymphoma and leukemia.


Feline Immunodeficiency Virus is equivalent to HIV in humans. It is highly contagious and is known as the “mean cat” disease since it is spread most commonly through bites. This disease is most prevalent in young, outdoor male cats. It also causes immunosuppression and predisposes those affected to secondary infections.

There are no effective treatment options for either virus, but supportive care and maintenance of good health can help improve your cat’s quality of life. Both diseases become progressively worse over time. Most FeLV-infected cats succumb to the disease within 2-3 years; however, some cats live much longer with the proper veterinary care. The prognosis for FIV-infected cats is much more guarded, and usually cats succumb to the disease just months after diagnosis.

Vaccination against at-risk cats is important to reduce the prevalence and spread. Cats that are infected should be kept separate from other cats within the household and be strictly indoors for the duration of their lives. Your veterinarian may recommended repeating this combo tested yearly or as needed for at-risk cats.