Thanks to the advances of modern medicine, the development of vaccines has dramatically lessened the frequency of many infectious diseases. The best way to keep your kitten free from these contagious diseases is by following a proper vaccination schedule. Vaccines (also known as "kitten shots") are divided into core vaccines, which are given to every cat, and non-core vaccines, which may be given to some cats based upon their lifestyle and risk factors. Your veterinarian will be able to make specific recommendations for your individual kitten.
How Do Cat Vaccines Work?
In order to understand which vaccines are recommended and how they are given, it is important to first take a step back to understand how the basics of how vaccines work. Long story short, vaccines stimulate the immune system to form antibodies. Antibodies are proteins produced by the immune system that destroy particular organisms that invade the body and protect against the invasion of certain organisms. Antibodies are specific to a certain disease.
What Are Maternal Antibodies?
Cats that have previously been either vaccinated against or infected with certain infectious diseases develop antibodies that protect them from being re-infected with these diseases. A mother cat then passes these antibodies through the colostrum to the kittens, conveying a degree of protection. The antibodies that a kitten receives in this manner are referred to as maternal antibodies. However, maternal antibodies only provide temporary protection against these infectious diseases, as their numbers typically decline around 12 weeks of age. It is important to remember that kittens only receive maternal antibodies for diseases which their mothers have active antibodies against. Therefore, if a mother cat has never been vaccinated against or infected with panleukopenia, she has not been able to develop any antibodies, so her kittens are not protected against this disease.
Vaccines are given to both kittens and adult cats alike in order to stimulate the immune system to form antibodies against diseases. In the initial kitten series, vaccines are given more frequently because when the maternal antibodies are still present, a kitten is unable to develop their own longer lasting antibodies. When the maternal antibodies begin to drop around 12 weeks of age, a kitten is able to mount their own antibody response. Vaccines are given every two to four weeks in the kitten series so that kittens who have not received maternal antibodies or those with either shorter- or longer-lasting maternal antibodies can form an appropriate protective response.
Core Versus Non-Core Vaccines in Kittens
The general vaccination guidelines for cats are published by the American Association of Feline Practitioners (AAFP). Experts agree that core vaccines are those that should be given to every cat. These core vaccines include rabies, feline panleukopenia (a parvovirus, also referred to as feline distemper), feline herpesvirus-1 and feline calicivirus. Feline panleukopenia, herpesvirus and calicivirus are typically merged into a combination vaccine.
Non-core vaccines are those that are given to cats whose lifestyle puts them at an increased risk of acquiring certain diseases. Whether or not to vaccinate with non-core vaccines depends upon a number of variables, including the age, breed and health status of the cat, as well as the potential exposure of the cat to an animal that has the disease, the type of vaccine and how common the disease is in the geographical area where the cat lives or may visit. The decision whether or not to vaccinate with non-core vaccines does not follow a one-size-fits-all approach. Your veterinarian will be able to discuss if any of these vaccines are appropriate for your kitten.
The non-core vaccines available include feline leukemia virus (FeLV), feline infectious peritonitis (FIP), feline immunodeficiency virus (FIV), Bordetella, dermatophytosis and Chlamydophila. The AAFP recommends against these vaccinations in adult totally indoor cats who have no exposure to other cats. It is suggested that all kittens, because they are most susceptible and their lifestyles may change at a later date, should receive an initial FeLV vaccination series. FIP, FIV and dermatophytosis vaccinations are not recommended due to a number of different reasons. The choice to use a Chlamydophila vaccine is based upon the prevalence of the disease and husbandry conditions, but this is rarely recommended.
When Should My Kitten Receive Vaccines?
Remember, the protection from maternal antibodies wanes when a kitten is around 12 weeks of age. Some kittens never received these maternal antibodies, some kittens lose their protection well before the 12 week mark and some retain these antibodies until closer to 16 weeks of age. As a result, it is extremely important to strictly adhere to the vaccination schedule set forth by your veterinarian to assure that your cat is best able to form their own protective antibodies.
With core vaccines, the combination vaccine of feline panleukopenia, herpesvirus-1 and calicivirus should be given between six to eight weeks of age with boosters every two to four weeks until a kitten is at least 16 weeks of age. The rabies vaccine is typically given at 12 weeks of age or later, depending on local laws. In order to remain protective, these vaccines must be given again one year after the last date of vaccination. After this point, the vaccines are typically given every three years, unless local laws require more frequent rabies vaccine administration.
Prior to the first dose of the feline leukemia virus (FeLV) vaccine, cats should be tested for this disease with a blood test that also checks for the presence of feline immunodeficiency virus (FIV). Kittens that test negative for FeLV can be vaccinated against this virus starting at eight weeks of age with one booster two to four weeks later. Subsequent FeLV vaccines are given annually.
Should other non-core vaccines be recommended for your kitten, your veterinarian will discuss the timing of these vaccines. However, these vaccines are rarely recommended.
Do Indoor Kittens Still Need Vaccines?
Absolutely, yes. While indoor only cats are at a lower risk of acquiring these contagious diseases than cats that also spend time outside, it is still possible for them to become infected. Even the most timid cat may accidentally get outside from time to time, and could come in contact with outdoor cats or wildlife. Likewise, situations have occurred where bats have gotten into homes and spread rabies to unvaccinated indoor cats. Rabies is a fatal disease in animals and requires extensive post-exposure prophylaxis treatments in people, provided that it is diagnosed in a timely manner. It is simply not a risk worth taking. The risk of developing an adverse vaccine reaction is much lower than the risk of developing these serious infectious diseases.
If you have any questions or concerns regarding your individual kitten’s vaccine series, discuss them with your veterinarian. The cost of kitten vaccinations is negligible relative to the cost of treating these diseases. Pet owners and veterinarians must work as a unified team to keep kittens both happy and healthy.