Since 1796, when Edward Jenner first injected an eight year old boy against smallpox using material from cowpox blisters he collected from a milkmaid’s hand, we have been working to protect people from disease by using the body’s own immune system. Over the centuries, continued research and the development of new vaccines has led to the control or elimination of many diseases that affected or killed millions of people and animals.

Unfortunately, vaccines have become a victim of their own success as people forget the historical ravages that these diseases once caused. This has also led many people, often without the benefit of data to support their beliefs, to dismiss vaccines as either unnecessary or even harmful. I readily admit that vaccinations have the potential to have an adverse effect in some individuals, but in medicine there will always be that element of benefit and risk as we deal with the unique biology of each individual. Fortunately, research has been ongoing for literally centuries to develop vaccines that provide protection while trying to minimize adverse reactions. There is also ongoing research looking at the duration of immunity that a vaccine produces so that better recommendations can be made regarding the required frequency of vaccinations.

If we look at the vaccinations for dogs and cats we can divide all of the vaccines into either core or non-core. A core vaccine is one that is highly recommended, or even legally required, in the case of rabies vaccinations, as a public health measure. A non-core vaccine is one that may be recommended for your pet based on their lifestyle. Does your dog go for walks around the neighborhood, go to a dog park, or to a groomer? Then vaccination against kennel cough caused by Bordetella is highly recommended. Here in the Pacific Northwest you should also consider vaccinating that same dog against Leptospirosis, a disease that can affect both pets and people. Lyme disease, something very common when I practiced in the Boston area, is quite rare here, and might only be considered for a hunting dog that travels out of state.

For cats, the choices are based on whether they are indoors only or have the chance to spend time outdoors. Vaccination against feline leukemia virus (FeLV) would be a non-core vaccine that is highly recommended for a cat that goes outdoors.

How often a pet should be vaccinated is a question many owners ask. What is the balance between the protection that an immunization provides and the risk of an adverse reaction to that vaccine? We know some vaccines only provide short term protection of a year or less. Other vaccines can provide a level of protection that can last for years. The latest recommendations for both dogs and cats are to immunize them with a series of core vaccines when they are puppies and kittens, combined with the non-core vaccines recommended for their lifestyle. This is followed by a set of adult vaccines at one year of age. After that, vaccines are generally recommended on a three-year interval, except for those vaccines, such as Bordetella, Leptospirosis, and feline leukemia virus, which should be administered annually.

Some people prefer to have their pet’s level of immunity against a specific disease, called a titer, measured instead of having them receive immunizations on a regular basis. Measuring titers involves a blood test, and, except for rabies immunizations which are legally required for public health, can help minimize the number and frequency of vaccinations your pet receives.

Remember, not every dog or cat needs to be vaccinated for every possible disease. You need to discuss your pet’s lifestyle with your veterinarian to help decide the best combination of benefit and risk for your pet.

For additional information about vaccinations for your pet consider visiting the website of the American Association of Feline Practitioners at  www.catvets.com or the website of the American Animal Hospital Association at www.healthypet.com.

DOGS

Core Vaccines 

Canine distemper virus

Canine parvovirus

Canine adenovirus
(hepatitis)

Rabies

Non-Core Vaccines

Bordetella (kennel cough)

Leptospirosis

Lyme disease

CATS

Core Vaccines

Feline parvovirus

Feline herpesvirus

Feline calicivirus

Rabies

Non-Core Vaccines

Feline leukemia virus

Dr. Kiel is the U.S. Army veterinarian currently supporting NAS Whidbey Island and Naval Station Everett. His columns appear the first and third Friday of each month. Please send questions or comments to Dr. Kiel at joseph.kiel@navy.mil.