If you're a pet owner, you've seen them in your mailbox — postcards from the neighborhood veterinarian reminding you that it's time for Fido's distemper vaccine or Fluffy's leukemia shots.
After all, vaccines are a standard in health care. We vaccinate our children against hepatitis, polio and influenza when they're infants and toddlers, giving up to two boosters of some vaccines until puberty. But then we stop.
Not with our pets, though. In fact, we continue bolstering the immunity of our pets until they are well into their senior years. That has spawned a debate as fierce as any fighting pit bull: To vaccinate or not to vaccinate.
Many veterinarians believe the practice of annual vaccinations is an unnecessary evil, responsible for such diseases as allergy, seizures, anemia, even cancer. They say vaccinations make our animals vulnerable to some of the top diseases plaguing our pets, and that rather than building up immunity we are overwhelming their immune systems. Others would rather stick to tradition and say that vaccinating has warded off the most deadly animal diseases over the past 30 years, so why question it now.
Lack of Scientific Evidence
Dr. W. Jean Dodds, president of the nonprofit animal version of the Red Cross called Hemopet, was one of the pioneers of the vaccine debate, an issue she says has been percolating for the past 10 years. She says as the profession started looking into exactly how the recommendations for annual vaccines arose, they started realizing that they were just that — recommendations. And in fact, they were not based on scientific evidence.
Dodds says that after 20 years of following the United States Department of Agriculture and the drug manufacturer's recommendations to make annual vaccines a standard in veterinary care, professionals who first challenged the standard school of thought were considered rebels. Her arguments were challenged by other veterinary professionals whose belief in the duty to vaccinate was galvanized by episodes such as the deadly parvo virus epidemic in the late 1970s that killed thousands of dogs and was only halted by mass administration of the parvo vaccine.
But Dodds says an unfortunate observation led many vets to begin to reconsider current vaccination protocol. In 1991, three years after Pennsylvania issued a mandatory rabies vaccination requirement for cats, Dr. Mattie Hendrick's lab at the University of Pennsylvania noted a connection between the surprising increase in the number of sarcomas, or cancerous tumors, and vaccination in cats. It seemed that in some cats, rabies vaccinations were leading to an inflammatory reaction under the skin.
Shortly after, researchers at the University of California at Davis showed that feline leukemia vaccines were also likely to cause sarcomas, and to an even greater degree than the rabies vaccine. Further investigating led researchers to estimate the prevalence of vaccine-induced sarcomas to be as much as one cat in 1,000, or up to 22,000 new cases of sarcoma a year.