Rather than having your adult dog or cat vaccinated every year, consider these important factors and make an informed decision that will optimize their health and well-being.
Over the past decade, we’ve heard a lot about the risks associated with over-vaccination in dogs and cats. A growing number of pet parents are now thinking twice before subjecting their four-legged friends to annual boosters, once their pets received their baseline vaccines when they were young. For those still on the fence, this article explores the important factors to consider when creating vaccination strategies for adult dogs and cats.
Benefits and risks of vaccination
There is no doubt that the application of modern vaccine technology has enabled us to effectively protect pets (and humans) against serious infectious diseases. However, vaccinations are increasingly recognized (though still rarely) as contributing to immune-mediated diseases of the blood, skin, intestines, bones and joints, bone marrow and organ failure, excitation of the central nervous system and behavioral aberrations. A genetic predisposition to these adverse events (called vaccinosis) has also been documented. It must be recognized, however, that we have the luxury of expressing these concerns today only because the risk of disease has been effectively reduced by the widespread use of immunization programs. Nevertheless, the accumulated evidence indicates that vaccination protocols should no longer be seen as a “one size fits all” program.
In cats, although the side effects of vaccines are less common, aggressive tumors (fibrosarcomas) can sometimes appear at the vaccination site, as is the case in dogs. Other cancers, such as leukemia, have also been linked to vaccines.
Dosage of the vaccine in dogs – size matters
Dogs currently all receive the same amount of vaccine, regardless of size or breed. Not surprisingly, more adverse events have been documented in small dogs. Logically, toy dogs and small dogs should require fewer vaccines than giant dogs and large dogs in order to be fully immunized. Likewise, puppies (and kittens) should need fewer vaccines to immunize than adults.
To support the size hypothesis, I studied healthy, adult, small breed dogs that had not been vaccinated for at least three years. The dogs were given a half dose bivalent vaccine against distemper and parvovirus, whereby all of them developed increased and sustained serum vaccine antibodies securities. Presumably, this approach would apply to puppies as well, and more research is needed.
Vaccinate judiciously, and only when needed
There is no such thing as an “up to date” or “due” vaccination. When adequate immune memory has already been established, there is little reason to administer booster vaccines, and it would be unwise to introduce unnecessary antigens, adjuvants and other excipients, as well as preservatives in doing so. Serum antibody titers can be measured every three years, or more often if necessary, to assess whether the humoral immune response of a given animal has fallen below levels of adequate immune memory. In this case, an appropriate vaccination booster can be administered. For legally required rabies vaccines, these alternative options are often limited.
Vaccination can provide an immune response similar in duration to that following natural infection. In general, adaptive immunity to viruses develops the earlier and is very effective. Such antiviral immune responses often result in the development of sterile immunity, and the Duration of Immunity (DOI) is often permanent. In contrast, adaptive immunity against bacteria, fungi or parasites develops more slowly. The DOI is generally short compared to most systemic viral infections. Sterile immunity to these infectious agents is less often generated. The titles do not distinguish between immunity generated by vaccination and / or exposure to disease, although the magnitude of immunity produced only by vaccination is generally lower.
In adult dogs and cats, baseline vaccines should not be given more than every three years, and serologic and challenge studies actually indicate that protection likely lasts much longer than that – seven to nine years. With this in mind, measuring serum antibody titers is preferable to regular boosters.
Compliance or resistance to current vaccine guidelines
The questions discussed above have been legitimately raised for over two decades, but why is this knowledge still considered controversial? Have veterinarians adopted national and international policies on vaccination guidelines? Do parents of dogs and cats trust vets to know about these issues? Do they believe vets have a conflict of interest if they earn income from annual booster vaccinations? While some vets still tell their clients that there is no scientific evidence linking vaccinations to side effects and serious illness, this mistake confuses an impressionable client. On the other hand, vaccine and anti-vaccine fanatics are teeming with hysteria and misinformation. Neither of these polarized opinions is helpful.
Practicing veterinarians may simply believe what they originally learned about vaccines and are therefore less inclined to alter or “fix” what is perceived to be uninterrupted. The annual vaccination has been the single most important reason the majority of people take their dogs and cats to the vet for an annual check-up or “wellness visit”. When combined with an inability to understand the principles of vaccine immunity, it is not surprising that attempts to change vaccines and immunization schedules have created significant controversy.
As the 2003 American Animal Hospital Association guidelines state: “No vaccine is always safe, no vaccine is always protective, and no vaccine is always indicated. Misunderstanding, misinformation and the conservative nature of [the veterinary] professionals have largely slowed down the adoption of protocols advocating a reduction in the frequency of vaccination. Immunological memory provides durations of immunity for basic infectious diseases which, by far, to go past traditional recommendations for annual vaccination. This is supported by a growing body of veterinary information as well as a well-developed epidemiological vigilance in human medicine which indicates that immunity induced by vaccination is extremely durable and, in most cases, lifelong. These statements were revolutionary then and still apply today.
Vaccines must be individualized for each patient
“Vaccination should only be one part of a holistic preventive health care program for pets that is most simply delivered as part of an annual check-up consultation,” said the late professor. Michael J. Day. “Vaccination is an act of veterinary science which must be considered as individualized medicine, adapted to the needs of each pet and provided as part of a preventive medicine program during an annual health check-up. Before vaccination, it is therefore important to consider the individual risk of exposure of your dog or cat to the disease in question, as well as your location and lifestyle factors.
While vaccines have traditionally been a part of every dog and cat’s annual health check, things are changing. The health risks of over-vaccination, the increasing use of titration tests, and studies demonstrating vaccine immunity durations of seven to nine years, are leading more and more people to reconsider annual boosters and work with integrative or holistic veterinarians to create vaccination programs adapted to the needs of their dogs and cats.