Are Cats and Dogs Being Overvaccinated?
The concept of vaccination is simple. Ideally, vaccines introduce a disabled or harmless form of a pathogen into the body, where the immune system reacts to it, rendering the body immune to both the harmless and the dangerous form of the bug.
Vaccines have saved countless human and animal lives. The world is now free of smallpox. People living in all but the least developed countries are free from the scourge of polio. Fully vaccinated dogs are at almost no risk of parvovirus. Cats benefit from vaccines against panleukopenia and the feline leukemia virus.
However, recent years have seen a pushback against vaccines in people and animals. On the human side, an study that purported to link vaccines to autism has led to much antivaccination activism. That study has since been discredited and the authors disgraced. However, its effects are still being felt.
In animals the arguments against excessive vaccination are stronger. In cats, the feline leukemia and rabies vaccines have been linked to tumors called sarcomas. Although the risk of sarcomas is low (perhaps one in 3,000 to 10,000), it is real — unlike the supposed autism link in humans.
Vaccines have not been linked to tumors in dogs, but there does appear to be a link between vaccines and some autoimmune system diseases, but the rate is extremely low.
Vaccines are one of the most important and most beneficial developments in the history of medicine. In terms of lives saved and good done, they're right up there with handwashing, clean drinking water, antibiotics, anesthesia, and pain killers. There is no doubt that vaccines have greatly benefited dogs and cats in general, and that every individual animal benefits from an appropriate vaccination protocol.
However, you don't need to subscribe to the mentality of one-size-fits-all, vaccinate every dog and cat for every disease every year. Individual animals have different needs based upon their life stages, lifestyles, and the level of function of their immune systems.
That last item is what makes determining the ideal vaccination frequency for a pet so difficult, because it is not possible to fully measure the status of the immune system. (Although tests called titers are available, they measure only one half of the system, called humoral immunity. No test exists to measure the other half, cell-mediated immunity.)
Animal vaccination guidelines have been developed by leading organizations such as the American Association of Feline Practitioners and the American Animal Hospital Association. I recommend that you seek out thoughtful veterinarians who use the guidelines as they are intended -- they're guidelines, not rules.
A good vet will take time to discuss your pet's needs and lifestyle. A good vet will work with you to develop a vaccine protocol that makes sense. A good vet will not give every pet every vaccine every year.