In recent years, the practice of giving annual booster shots to dogs and cats has increasingly come under fire. Kirk's Current Veterinary Therapy--considered the veterinarian's "bible"-- states:
"A practice that was started many years ago that lacks scientific validity or verification is annual revaccinations. Almost without exception there is no immunologic requirement for annual revaccination. Immunity to viruses persists for years or for the life of the animal."
The Damage Done
According to top veterinary hematologist Dr. Jean Dodds, the "evidence implicating vaccines in triggering immune-mediated and other chronic disorders (vaccinosis) is compelling." In addition to the risk of anaphylactic shock, which occurs shortly after vaccination and can be fatal, there is a risk of long-term damage ranging from autoimmune disorders and cancer to chronic skin and ear conditions.
In fact, the journal of the American Veterinary Medical Association stated as far back as 1996 that "There is no scientific data to support a recommendation for annual administration of vaccines. Furthermore, repeated administration of vaccines may be associated with a higher risk of anaphylaxis and autoimmune diseases." (J Am Vet Med Assoc. 1996; 208)
Polyvalent vaccines (combo shots) are known to further increase the risk of adverse reactions. A study involving over a million dogs vaccinated at 360 veterinary clinics found that the risk of an adverse reaction "significantly increased as the number of vaccine doses administered per office visit increased; each additional vaccine significantly increased risk of an adverse event by 27% in dogs." (J Am Vet Med Assoc. 2005; 227: 1102–1108)
The Profit Motive
If top immunologists and major veterinary associations agree that annual vaccinations are completely unnecessary and potentially harmful, why, then, do many vets persist in recommending annual booster shots? According Dr. Karen Becker, DVM, nearly two-thirds of canine vet visits are for vaccinations, and these visits are highly profitable. Vaccine markup can be as high as 2,400-6,200%!
While the profit motive can't be dismissed--particularly in the case of the small, non-specialized, non-emergency veterinary practice--it's usually not the only reason many vets continue to push regular "boosters." Some are concerned about their legal liability if they recommend against vaccinating and an animal gets sick, while others reason that the "need" for annual vaccinations functions as a useful mechanism for encouraging owners to bring their dogs in for a checkup at least once a year.
Studies indicate that 95-98% of tested dogs have an adequate immune response to the canine parvo and distemper viruses up to seven years after being vaccinated (J Am Vet Med Assoc. 2000; 217: 1021–1024). It is virtually certain that immunity lasts even longer--most likely for the entire life of the dog--but at this point seven years is the longest time frame that has been studied.
If the thought of going without annual boosters terrifies you--or if your boarding kennel or training club requires proof of "current" vaccinations--consider titer testing instead. Titer tests measure the level of antibodies to a specific virus or other antigen that is present in your dog's blood. Titers are actually a far better guarantee of immunity than vaccinations, because vaccines may or may not "take" (seroconvert). There are three main reasons why dogs may not form immunity, even if injected with a modified live vaccine:
- The vaccine was prepared, stored, or administered incorrectly.
- The dog was not healthy at the time of the vaccination. Although vaccine labels clearly state that vaccines should be administered only to healthy animals, it is unfortunately common practice to vaccinate dogs with one or more ailments. A dog who's immune system is already taxed by an infection may not be able to mount an immune response to the vaccine.
- The puppy's maternal antibodies prevent the vaccine from triggering an immune response. This is why puppies are typically vaccinated every 2-3 weeks until they are about 16 weeks old. Since we don't know at what point the maternal antibody levels will be low enough to allow the vaccine to seroconvert, we vaccinate every couple of weeks, "just in case." Titer testing makes that unnecessary. You can vaccinate once with a single antigen modified-live vaccine, say at 12 weeks, wait 10 days, test titers, and know for sure if the vaccination "took."
One of the most effective weapons our pit bulls have in the fight against viral and bacterial pathogens is a strong immune system. Some holistic veterinarians, such as Dr. Charles E. Loops, go so far as to recommend that dogs not be vaccinated at all, not even as puppies. Instead, canine guardians should focus on building powerful natural immunity by feeding a species-appropriate raw diet and avoiding chemical insecticides and allopathic drugs such as antibiotics unless the drug is clearly indicated and the situation is potentially life-threatening.
Case in Point
A few years ago, a friend was helping someone treat a puppy who was deathly ill with parvo. My friend is an herbalist, and she was bringing the puppy herbal infusions and electrolyte solution several times a day.
At the time, she had four adult dogs of her own: two six year olds, a five year old, and a four year old. The two six year olds had received two parvo vaccinations as puppies, about a month apart, at 12 and 16 weeks. The five year old was adopted from a shelter where he was vaccinated despite being sick at the time. He was about eleven months old when he was adopted. The four year old had never received any vaccinations. All of the dogs were eating a species-appropriate raw diet, and none of them had been vaccinated as adults.
Parvo virus is highly contagious, and despite taking care to remove shoes before entering the house and putting clothes in the wash immediately, the virus somehow got tracked into my friend's house. The two six year-olds never got sick at all. They clearly still had immunity from their puppy vaccinations. The four and five year olds did get sick, but both managed to conquer the virus within a few days. The four year old was particularly resilient, maintaining her appetite and energy level despite heavy vomiting and diarrhea. And yes, the puppy pulled through too, though it was a very close call.
Canine Vaccination Guidelines
Here are some vaccination guidelines from top veterinary immunologists such as Dr. Ronald D. Schultz, professor and chair of the Department of Pathobiological Sciences at the University of Wisconsin School of Veterinary Medicine.
- Vaccinate only when:
- The pathogen in question is serious and typically life-threatening (this usually means you can skip vaccines such as Bordetella and focus instead on the real risks such as parvo and distemper).
- Your dog has a realistic chance of encountering the pathogen (this typically means you can skip vaccines such as Coronavirus)
- The vaccine is effective in preventing the disease in question (for instance, Dr. Jean Dodds advices that leptospirosis vaccines offer no protection against the bacterial strains responsible for the majority of leptospirosis cases; moreover, bacterin vaccines such as lepto, Bordetella, and Lyme provide only short-term immunity.
- The vaccine has a good safety record (the Lyme vaccine, for instance, has been implicated in causing side effects that mimic Lyme Disease symptoms, and the lepto vaccine also has an exceptionally high risk of adverse reactions).
- Don't use polyvalent vaccines such as 5-in-1 or 7-in-1 shots. Not only do they increase the risk of adverse reactions, but these shots typically contain lots of vaccines your dog doesn't need. If your vet doesn't stock single antigen vaccines, ask her to order them for you.
- Even single antigen vaccines should be administered at least two weeks apart (three or four weeks is preferable).
- Use a limited vaccination protocol for puppies. Dr. Schultz recommends vaccinating puppies once for canine parvovirus and once for canine distemper at 12-14 weeks using a single antigen, high titer, modified live vaccine. Test titers 10-14 days after each vaccination to check if the vaccine "took." If it did, there is no need to repeat the vaccination. Wait until your puppy is at least six months old before you vaccinate for rabies.
- Don't vaccinate dogs that aren't healthy or that have recently had surgery. Rabies is the only vaccine required by law, and in many states it's possible to apply for an exemption if your dog is not in good health or has had adverse reactions to vaccines in the past.
- Use titer tests instead of routine booster shots. With the new TiterCHEK™ quick test kit, your vet can tell you in 15 minutes what your dog's parvo and distemper titer levels are. While titer tests for other vaccines are available, Dr. Dodds believes that measuring titers for canine distemper and parvovirus is sufficient to convey accurate information about your dog's general immunological status.