Vaccines: How often does my pet need shots?

This seemingly simple question has a very complex answer. There are many theories being circulated that vaccines do not need to be given every year. Unfortunately deciding the proper interval is difficult due to lack of published studies on exactly how long immunity lasts and in which patient. Hopefully, in coming years the data will be there to give us specific guidelines. Until the research proves the exact duration of immunity we will not change our vaccination protocols for fear of providing you a false sense of security that your pet is protected. Having said that, because, like any medication, vaccines do carry some risk, we can work with you to individually tailor a vaccination protocol for your pet.

How are vaccines tested?

Vaccines are tested and approved in a similar manner to drugs. They are tested for side effects and effectiveness. To do this, special research dogs and cats are used. They are specially bred to be genetically similar. They are dewormed and placed in special cages to be able to monitor them closely. They then are vaccinated according to the vaccine recommendation. During the time in which the vaccines are being tested (one year for most vaccines), special blood tests for antibodies called titers are performed. The pets are monitored closely for signs of reactions or illness. When the trial is over, the pets are challenged (deliberately exposed to the disease which they were vaccinated). If no (or very few pets depending on the number of pets in the study) get disease and there are little side effects, then vaccine gets approved. While this is a gross oversimplification, this is how vaccines are tested. The vaccines we use, made by Fort Dodge, and are tested for one year. Because the government did not mandate further testing, the vaccine manufacturer did not test longer than the one-year period. To do a one-year study costs millions of dollars for laboratory fees, staff costs, the development of the vaccine, the establishment and support of the pets, and oversight to make sure the pets are taken care of in a humane manner.

How do you test for longer immunity?

In order to establish if the vaccines provide immunity for longer, the same studies would have to be undertaken for 1,2,3 or more years. Of course, the vaccine manufacturer will not pay for these tests. Likely it will be the veterinary colleges and private research groups, which will be doing these tests? Also important will be the individual factors, such as breed, age, and underlying health. For example, Rottweilers are much more susceptible to parvovirus than other breeds of dogs. Also immunity is not as good in older pets as younger ones. How will we know if their immunity is good? Titer tests can be performed. Titer tests check to see antibody level against certain diseases. For dogs, titer tests exist for distemper and parvovirus. For cats there are titers for Panleukopenia, Rhinotracheitis (herpes), calicivirus, and chlamydia. Unfortunately there is not a titer for all vaccinations. Generally, the higher the titer, the better the immunity. The downside to titers is they are not 100% reliable and they are more expensive than the vaccines. The titers test for only antibodies and not the whole process of immunity. There also haven’t been studies comparing titers followed by a challenge. Titers are sent to an outside laboratory and results are not immediate. Also titers only test for immunity when the test is performed, not for immunity months from now.

What should I do?

To decide how often to vaccinate is based on your individual pet’s lifestyle and overall health. Some pets have health conditions in which we recommend against vaccination. For all others, balance risk of disease vs. risk of vaccination. For most dogs and cats (99.9%) vaccination causes no problems other than a transient lethargy, fever, and lack of appetite which lasts a day or so. So risk is minimal. Of course, if your pet is the 0.1%, the side effects can be more severe and you may be unwilling to take that risk. Generally pets that are at risk are pets that go outdoors and frequent places other pets have been. Pets that go to grooming, dog parks or boarding are at an especially high risk. You must balance their exposure level. The only legally required vaccination is rabies for dogs. If you choose not to get the vaccines annually, a titer test is strongly recommended. Our point of view, as veterinarian, if by going to a 3 year vaccine and it is protective for 90% of pets, 10% of pets that we think are protected are not. Certainly this could lead to disease outbreaks and as a pet owner you would be very unhappy.
What steps can I take to decrease risk of side effects if I need to get the vaccines for my pet?

As a convenience, since most pet owners have difficulty having the time to go to the veterinary office, we give all the vaccines at once. Medically, this isn’t the best thing to do, but we try to make things as easy for you as possible. Also we give combination vaccines so we don’t have to poke your pets as often. As an option we can spread out the vaccines into more visits and more injections. This helps to reduce risk of serious reactions and to reduce the lethargy and fever that some pets have following vaccines.

My pet is coming to Orange Villa Veterinary Hospital for grooming and/or boarding

In order to protect all of our patients from serious disease, we require vaccinations to be current. If you have decided that you do not want vaccinations, then prior to your pets stay titers must be performed so that we are ensured of your pet’s safety.

Dogs:

Distemper: Vaccine or titer within 1 year
Parvovirus: Vaccine or titer within 1 year
Rabies: Current within 3 years for dogs older than 1, 1 year for one-year old dogs or veterinary waiver
Bordetella: Current within 1 year (very low incidence of reactions)

Cats:

Panleukopenia: Vaccine or titer within 1 year
Rhinotracheitis: Vaccine or titer within 1 year
Calicivirus: Vaccine or titer within 1 year
Rabies: Current within last 3 years for cats >1 year, within last year for cats <1 year or veterinary waiver
FIP: Current within last year (very low incidence of reaction)
Feline Leukemia: Current within last year or leukemia ELISA test-if positive, cat can be boarded but isolated from other cats.

If you decide that annual vaccination is not for your pet, it is still imperative that you still have an annual physical examination for your pet to ensure their health. This examination is actually more important than the vaccines to help promote good health for your pet. We recommend examination for adult pets every 6 months.

Please, if you have any questions, discuss them with us before making a decision whether or not to vaccinate your pet.

Please read the handout about vaccination on our website.

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