Morgan is doing all she can to protect her two dogs from over-vaccination. “I have a vet who does titer testing instead of giving shots every year,” she says. “My dogs are five years old now, and the tests show they’re still being protected by the vaccines they had when they were pups.” But it’s a different story when it comes to rabies. Morgan lives in a state where rabies shots are required annually, so her vet is obligated to vaccinate her dogs every year, regardless of whether or not they might still be protected by earlier inoculations.

Teresa, meanwhile, is an apartment-dweller whose cat died after suffering an adverse reaction from a rabies vaccine. “I don’t know why I had to get him vaccinated so often when we’re seven floors up and he never went out,” she says. “The chances of him ever coming into contact with a rabid animal were pretty small.”

Serious side effects

It’s a dilemma common to animal lovers across the U.S. and Canada. Some regions still require annual rabies vaccines, while many others now allow the three-year variety, but even that’s too frequent when you consider the negative side effects of over-vaccination. “Rabies is the vaccine most associated with adverse reactions because it’s so potent,” says renowned veterinarian Dr. Jean Dodds. “We have a lot of bad reactions, including fatal ones. They usually occur within two to three weeks after vaccination, although they can appear up to 45 days later. Because the rabies vaccine is a neurogenic protein, meaning it affects the nervous system, what you will often see is seizures or seizure-like disorders like stumbling, ataxia, dementia, and some demyelination, where the animals become wobbly and don’t have proper motor skills. You can also have an autoimmune-like destruction of tissues, skin, blood, joints, the liver or kidneys.” Dr. Dodds adds that animals already ill with immune-related diseases such as cancer can be even more negatively affected. “Often, this is the last thing that causes the animal’s demise.”

Despite all this, federal law still demands that companion animals be regularly vaccinated against rabies, even if you keep your animals indoors or live in an area where rabies is unlikely to be a major problem. The main reason is that rabies can afflict humans as well as dogs and cats. “Rabies is fatal to all mammals,” says Dr. Dodds. “This is an issue to protect the public health, not the animals. The primary goal of the law is to protect people from rabies.”

While there’s no denying that rabies is a serious disease, and that both humans and animals protection from it, the question remains: why subject dogs and cats to the potentially serious side effects of the vaccination on an annual or even a triennial basis, when the duration of immunity (DOI) is probably much longer?

The need for new legislation

It’s a question that Dr. Dodds and several other professionals asked themselves when they started The Rabies Challenge Fund in the fall of 2005. “From challenge trials, we know the DOI for regular vaccines is seven to nine years, if not longer. So why would the rabies vaccines, being so potent, not have an even longer DOI? We decided the thing to do would be to design a study to federal government standards that would determine if the DOI is longer than three years.” Challenge studies in France have demonstrated that the rabies vaccine has a DOI of at least five years, but this information is not accepted by federal and state legislatures in the U.S., hence the need for a domestic study.

The Rabies Challenge Fund is a nation-wide effort. Along with Dr. Dodds, who is based in California, the study involves Dr. Ron Schultz of the School of Veterinary Medicine at the University of Wisconsin, and vaccine disclosure activist Kris Christine, who lives in the northeast and has already worked with Dr. Dodds on other vaccine-related issues in that region. “We asked Dr. Schultz to do the study and he was delighted,” says Dr. Dodd. The group was even more delighted when the University of Wisconsin agreed to cover almost half the cost of overhead for the study. “It shows they believe very strongly that this is information we need.”

How will the study work?

Dr. Dodds and her colleagues officially registered The Rabies Challenge Fund in December of last year. Since then, they have been working diligently to raise the money needed to fund the actual study, which will involve two separate groups of 20 dogs each, one to be studied for five years’ DOI, and the other for seven. “We’ll do the two groups in parallel, and continue 20 of the five-year dogs to seven years.” By monitoring the animals’ antibodies and other benchmarks, Dr. Schultz will be able to determine the DOI for the rabies vaccine over these periods, thereby showing that the initial vaccines given to puppies and kittens before they’re a year old remain fully effective for many years, perhaps even for life. The fund will also finance a study of the adjuvants used in rabies vaccines and establish an adverse reaction reporting system.

But more money is needed before work can start. “We require $177,000 in the first year,” says Dr. Dodds. “So far, we have $65,000, so we’re still short of our goal. We also have some pledges that will become active once we achieve 60% of the amount we need. And we’ve had some substantial donations from Canada, even though what we do might not be accepted there. People still felt compelled to donate.”

One of the unique things about The Rabies Challenge Fund is that it’s being funded by animal guardians and others who feel passionate about this issue. “Kris and Ron and I want this to be a grassroots program,” says Dr. Dodds. “We know a company could come in and give us a whole bunch of money to do the study, but it’s nice to know that the project started and evolved from people in the grassroots.”

Donations may be sent to The Rabies Challenge Fund Charitable Trust, c/o Hemopet, 11330 Markon Drive, Garden Grove, CA 92841. Or contact Dr. Jean Dodds at Hemopet@hotmail.com or Kris Christine at LedgeSpring@Lincoln.midcoast.com. All donations are tax deductible.

What about other vaccinations?

Rabies isn’t the only vaccine to cause controversy over the last number of years. The adverse effects of over-vaccination in general have been widely publicized, with the result that more and more animal guardians and professionals are lobbying for and working towards a reduction in the number and frequency of vaccines our dogs and cats receive. Although vaccinations are available for a whole range of diseases, many vets now agree that only a handful are really necessary, and even they need not be given every year. These are referred to as core vaccines, and include the following (along with rabies):


  • Canine distemper (CDV)
  • Canine parvovirus-2 (CPV-2)
  • Canine adenovirus-2 (CAV-2)


  • Feline parvovirus (FPV)
  • Feline herpesvirus-1 (FHV-1)
  • Feline calicivirus (FCV)

Although the American Animal Hospital Association recommends that each of these be given every three years, studies have demonstrated that the duration of immunity for all these vaccines is seven to nine years. You can help protect your animal from the effects of over-vaccination by asking your vet about titer testing. This simple test checks your animal’s blood for the antibodies that protect against a particular disease. If the levels are high enough, the animal doesn’t need revaccination.

“Titer testing is useful for puppies or kittens that were properly vaccinated initially, at the one year period when a booster is recommended or optional,” says Dr. Dodds. “If the titers are sufficient, then a booster isn’t needed. After that, titers can be done annually or every two to three years depending on the wishes of the client and her veterinarian. The titers provide assurance that the animal has pre-existing measurable immunity to, and immune memory for, the clinically important infectious agents.”


Ann Brightman is Managing Editor for Animal Wellness Magazine and Integrative Veterinary Care Journal. A lifelong animal lover, she has also been a writer and editor for over 25 years. Ann is a member of the Professional Writers Association of Canada and is also a Tai Chi instructor.