A COMMON quandary these days, especially as we hear more and more about the often devastating side-effects of over-vaccination, is how do we prevent our dogs or cats from contracting infectious diseases that can often be fatal, while also protecting them from the equally serious health consequences of too many shots?
The best strategy is to learn which vaccines are absolutely necessary (the core vaccines), why they're needed, and what the minimum requirements are for each to ensure protection from disease without over-vaccinating.
"Core vaccines are those that every dog or cat should receive, regardless of geographic location or lifestyle," says Dr. Ron Schultz, Professor and Chair of the Department of Pathological Studies at the University of Wisconsin-Madison's School of Veterinary Medicine. For dogs, the four core vaccines are canine distemper (CDV), canine parvovirus-2 (CPV-2), canine adenovirus-2 (CAV-2) and rabies (Rabies is of course not present in some countries and is not on that country's list of core vaccinations. But if the dog must travel outside that country then rabies vaccination is required for its own protection).
The vaccinations listed above are considered core because the diseases they protect against are distributed over a wide area and have a high mortality rate. "These vaccinations are absolutely necessary," says Dr. Schultz. "You want the vaccine to be the first antigens to prime the immune system. You don't want to leave it up to natural immunization or exposure." This is because, when compared to the actual disease-causing virus, the vaccine is a safer way to protect the animal.
"If the vaccine is live, it's attenuated. If it's killed, it can't cause disease," explains Dr. Schultz. "It's true that many puppies that never see a vet get naturally immunized by exposure to distemper, as an example, but for every one that gets vaccinated, probably another would have died if the first encounter with distemper occurred prior to vaccination."
Although core vaccines are necessary to protect your companion from infectious disease, even these do not need to be given on an annual basis.
"That's what we're trying to change," says Dr. Schultz. "What we recommend is that puppies get the core vaccines at least once at or over the age of 12 weeks. The 12 weeks is significant, because prior to that, many animals still have passive maternal antibodies that will block immunization, which means they may not respond to the vaccine and are therefore unprotected against the disease. American Animal Hospital Association (AAHA) guidelines recommend vaccinating again at one year, and once every three years after that, although even that may not be necessary. I have studies that show duration of immunity at seven to nine years for all the core vaccines except rabies, and even on an antibody basis I can show that rabies gives much longer protection than three years," says Dr. Schultz.
Recent studies have cast new light on vaccination issues, prompting organizations such as the American Veterinary Medical Association, American Association of Feline Practitioners, and American Animal Hospital Association, to issue reports suggesting a need to revise some commonly accepted practices. Veterinarians have been advised to keep informed of the latest developments in vaccines and vaccinations; to communicate with clients on the benefits and risks associated with the administration of any given vaccine; and seek the client's consent to the vaccinations offered. The Veterinary Board urged veterinarians to review their vaccination protocols. It was noted that mere adherence to custom may, in some cases, be insufficient to meet the evolving standard of care for administering various vaccines. For example, coronavirus vaccines are still being routinely prescribed for dogs and cats by some veterinarians, although recently published positions of the veterinary associations unanimously do not recommend them.
Indications are that not enough is being done to inform the client of the need for the offered vaccines and the securing of informed consent. This simply involves a veterinarian providing enough information about the vaccines to the client so that he or she can give a reasoned consent to the recommended vaccines. This, in turn, requires a discussion of risks versus benefits of vaccination on a pet-by-pet basis.
The benefits of certain vaccines, for example distemper and parvovirus, are well known but a vaccine for Lyme disease, where risk is not the same in all locations, may need more explanation. Options to a vaccine may be available. Less frequent vaccinations may provide the necessary protection in many cases.
Once the risks and benefits of the vaccines have been explained to a client, the veterinarian should seek the client's consent for the recommended vaccines. A written authorization to vaccinate is recommended, but if a written authorization is not used, the patient record should be carefully noted to show that the client approved the vaccines after an explanation of benefits and risks. Examples of model consent forms are now widely available.
Dr Schultz noted that dogs properly immunized in puppyhood maintain lifetime immunity to canine hepatitis, distemper, and parvovirus.
Dr. Bob Rogers, DVM, Critter Fixer Pet Hospital, Texas, says: "Every three years is probably a completely arbitrary number. I've told my clients that after one year of age they don't need to vaccinate any more." Rogers estimates that in nine years, he has used this protocol on some 30,000 dogs - "and I haven't had one vaccine failure".
Jean Dodds, DVM, a world renowned vaccine research scientist, in Santa Monica, CA, said: "There never was any data that suggested vaccines must be given yearly. Veterinarians assumed there was data but there wasn't." Vaccines like parvovirus and canine distemper are responsible for many diseases of the immune system in dogs, she contends. Anemia, arthritis, epilepsy, thyroid disease, liver failure, diabetes, allergies and other conditions, she believes, are linked to vaccines.
"Approximately five to 10 percent will develop problems," Dodds said. "That increases to 20 percent in pure breeds. But there is really no breed that is not at risk. The only vaccination needed", she asserts, "is the rabies vaccine because it is legally required. Dogs' immune systems mature fully at six months old", she explained. If canine distemper and parvovirus vaccines are given after six months, a pet has immunity for the rest of its life.
However, if another vaccine is given a year later, antibodies from the first vaccine neutralize the second vaccine, producing little or no effect. Not only are annual boosters for parvovirus and distemper unnecessary, they subject a pet to potential risks of allergic reactions and immune-mediated hemolytic anemia.
Dr. Rogers agrees. "Dogs no longer need to be vaccinated against distemper and parvo every year - once the initial series of puppy vaccinations and first annual vaccinations are completed, immunity persists for life. Antibodies from the initial vaccine block the subsequent vaccines from having any effect. Vaccines against Corona virus, Leptospirosis and Lyme disease should be avoided," he said. - Article is a shortened version of material submitted by Kris Christine of Alna
