You know your pet needs vaccines, but do you know how they work? Or which diseases vaccines protect against? Following is a discussion on all things vaccines—from what they are, to how often they need to be given, to where they should be administered. If you’ve got questions about vaccines, you’ll find the answers here.

What are vaccines?

Vaccines are injections that are given to your pet (and to people) to prevent infectious diseases. Vaccines contain the specific organism that causes the disease, which, when injected, stimulates your pet’s immune system to create antibodies against the disease. In this way, your pet’s body forms “memory cells” capable of responding to disease rapidly. 

You may wonder why your pet doesn’t actually get the disease that is injected—what differentiates a vaccine, which stimulates the production of disease-specific antibodies, from the actual disease itself? 

The answer is simple. Vaccines contain an organism (parvovirus, for example), but not in its original, infectious form. Some vaccines are called modified live vaccines (MLV), some are killed vaccines, and some are recombinant DNA vaccines, but your pet is not given any vaccines that can actually cause the disease they protect against. 

  • Modified live vaccines (MLV) — MLVs are a weakened form of the organism that causes a disease. They work well, because they are similar to the infection they are trying to prevent. 
  • Killed vaccines — These vaccines contain a killed version of the disease-causing organism. The protection they provide isn’t as strong as MLV vaccines, so your pet will likely need several boosters to be adequately protected. 
  • Recombinant DNA vaccines — Genetic engineering is used to program non-harmful organisms to produce the same immune-system stimulation that the harmful organism would produce.

Which vaccines does my pet need?

Pets used to be given every available vaccine every year, but most veterinarians now tailor vaccine schedules to meet the needs of individual pets. For instance, a hunting dog who frequently spends time in the woods has a decidedly different lifestyle than the Chihuahua who lives in a city apartment and travels in his owner’s purse. These dogs will need different vaccines, the same way a solely indoor cat has different needs than an outdoor cat. 

Vaccines, in general, are divided into two categories—core and non-core. Core vaccines are those given to all pets, regardless of lifestyle, whereas non-core vaccines are lifestyle-specific. The goal is to choose vaccine schedules judiciously, so that pets are protected but not over-vaccinated.  

Core vaccines for dogs include:

  • Distemper
  • Hepatitis
  • Parainfluenza
  • Parvovirus
  • Leptospirosis
  • Rabies

The first four core vaccines are typically given in a single injection as a combination vaccine.

Non-core vaccines for dogs include:

  • Canine influenza 
  • Lyme
  • Kennel cough
  • Rattlesnake 

Core vaccines for cats include:

  • Feline herpesvirus
  • Feline calicivirus
  • Feline panleukopenia 
  • Rabies 

The first three core vaccines are typically given in a single injection as a combination vaccine.

Non-core vaccines for cats include:

  • Feline leukemia virus (FeLV)
  • Feline immunodeficiency virus (FIV)

How often will my pet need vaccines?

When your pet is young, he will go through a series of vaccinations to ensure he is fully protected from disease. Typically, the combination core vaccines are started at 6 to 8 weeks of age and repeated every three to four weeks until 16 weeks of age. Non-core vaccines are generally given in two doses, three to four weeks apart, and the rabies vaccine is given once around 12 to 16 weeks of age. 

Adult pets will get both core and non-core vaccines, if necessary, at their one-year visit, along with a rabies vaccine. After that, the combination vaccine can be given every three years, and the rabies vaccine every one year or three years, depending on whether the vaccine is killed or recombinant DNA.

Are vaccines safe for my pet?

Vaccines can produce some unwanted side effects, but rarely, and the benefits far exceed the potential for side effects. It is important to consider vaccines from an individual standpoint as well as from a herd health standpoint, and to remember that when you vaccinate your pet, you prevent him not only from getting disease but also from spreading disease, thereby protecting other animals around him. 

Your pet may feel a little under the weather for a day or two after his vaccinations, but more than likely, he’ll be completely unfazed. Other more serious side effects are extremely rare, but include:

  • Anaphylactic reaction
  • Hair loss at the vaccine site
  • Vaccine associated sarcoma, in cats only

Vaccination is an effective and inexpensive way to keep you and your pets safe. Many diseases that vaccines prevent in your pet are potentially lethal, and some, such as rabies and leptospirosis, also pose a threat to humans. If you think your pet has fallen behind on his vaccines, don’t hesitate to give us a call.