Why Do Puppies And Kittens Need Vaccines? 

kitten photoPuppies and Kittens are born with an immune system that is immature so they are very susceptible to infection with common diseases. When Puppies and Kittens are not properly vaccinated they are at risk of infection from these life threatening diseases that are easily prevented with proper and timely vaccination.

Puppies and Kittens do get some antibodies and immunity against disease from their mother’s milk called maternal immunity. That immunity is short lived and limited; lasting usually only until the puppy or kitten is about 16 weeks of age.  It is important that puppies and kittens start their vaccine series early and continue through to 16 weeks of age as it is not known how strong the immunity is they get from their mother or when that maternal immunity disappears from the puppy’s or kitten’s system.

How Often do They Need Vaccines?

Vaccines are typically given in a series of shots usually 2-3 weeks apart in order for the body to make a protective amount of antibodies against disease. The vaccines that are given to Puppies and Kittens to protect them against the most common diseases are called “Core Vaccines”. The puppy and kitten visits to get vaccinated are also an important opportunity to examine your pet for possible issues, and to discuss nutrition, training, and other topics.

What Vaccines do They Need?

Core Vaccines

puppy photoFor Puppies the core vaccines are “DAPP” which stands for Distemper (D), Canine Infectious Hepatitis or Adenovirus (A) Canine Parvovirus (P) and Canine Parainfluenza (P); and Rabies. For Kittens the core vaccines are “FVRCP” which stands for Feline Viral Rhinotracheitis or herpes virus (FVR), Feline Calcivirus (C) and Panleukopenia (P); and Rabies.

Kittens (FVRCP) and Puppies (DAPP) should start their vaccine series around 6-8 weeks of age and get 2-3 boosters until they are 16 weeks of age when it is thought that maternal antibodies are gone from their systems. The first Rabies vaccine for Kittens and Puppies is usually give at 14-16 weeks of age.

Non Core Vaccines

Other vaccines that are often given to Puppies and Kittens are vaccines called “Non-Core Vaccines”. Non-Core Vaccines are those vaccines that are considered to be elective depending on the habitat the Puppy or Kitten will be living in.  For Puppies these vaccines include Lyme and Leptospirosis vaccines. In the state of Maine, these vaccines are very important as we do see both of these diseases here frequently. For Kittens a “Non-Core” Vaccine is for Feline Leukemia. This vaccine is highly recommended for all kittens in their first year. If they remain as indoor-only cats they may not need to be boostered.

Why do I Have to Vaccinate my Indoor Cat?

Many people wonder why their indoor only cat needs to get vaccines. Even when a cat is indoors only, there is still risk of exposure to rabies. Bats and other animals may enter the house, and cats can slip out the door unintentionally. Due to the seriousness of Rabies infection, the State of Maine has strict guidelines for vaccinating all pets. It is also critical to protect humans from any potential exposure by vaccinating all cats and dogs. If a cat is not up to date on Rabies vaccination, and there is an exposure, they are considered “un-vaccinated” by the State of Maine. The rules regarding exposure for un-vaccinated animals are very strict.

Additional Reading

If you are interested in reading and learning more about these guidelines please visit:


Both the American Association of Feline Practitioners and the American Animal Hospital Association have published guidelines for vaccination if you would like more information.