vaccination vs over-vaccination

Historically veterinarians and vaccine manufacturers for companion animals have recommended annual revaccination against the most common diseases. Annual revaccination was originally an arbitrary recommendation and was not based on any studies showing maximum duration of immunity. Yearly revaccinations became standard with most veterinarians because it also provided an incentive for owners to get a physical examination and health check.

Vaccinations have saved the life of countless numbers of animals but concerns about over-vaccination and potential adverse effects (Allergic (hypersensitivity) and immune-mediated reactions) have led to a reevaluation of the annual revaccination (booster). Vaccines are generally safe but do carry a minimal risk to the animal since they are designed to challenge the animal’s immune system to stimulate immunity to an infectious disease.

Puppy Vaccinations

Puppies are born without a developed immune system. Immunity to an infectious disease results form an adequate level of antibodies circulating in the dog which provides protection from the disease. Newborn puppies can obtain the antibodies they need to resist infection from their mother’s colostrum which is a form of milk the mother produces the first few days after birth. The newborn puppies may be able to absorb the antibodies up to 48-72 hours after birth.[1] If the mother has an adequate level of antibodies the puppies can be protected up to 14-16 weeks. (Maternal immunity) It is important for a puppy to get these antibodies from its mother’s colostrum because a puppy cannot develop its own immunity until its immune system is fully functional at about 6 weeks of age.[2] The reason puppies are recommended to get a series of vaccines starting between 6 and 10 weeks of age and then every 2-4 weeks after the first set of shots is to insure the puppy gets one dose of vaccine soon after the maternal immunity diminishes. If the maternal immunity is still present it will block the puppy from developing its immunity from the vaccination. There is a critical period of time during which the maternal immunity the puppy received from its mother is not high enough to prevent infection from a disease, but is still strong enough to block the puppy from developing its immunity to a vaccination. The puppy may be susceptible to the disease during this short time referred to as an “immunity gap”.[3]  A single vaccine (Canine Distemper Virus (CDV), Canine Parvovirus (CPV-2), Canine Adenovirus (CAV-2) is expected to provide protective immunity but only if the maternal immunity is absent. Puppies 14-16 weeks old are not likely to have interfering levels of maternal immunity that would interfere with the vaccination thus blocking the puppy from developing a natural immunity. If we wait until the puppy is 16-weeks of age to vaccinate, it would leave the puppy unprotected and vulnerable to viral diseases which is what we want to avoid.   This presents a challenge because 3-12 weeks (up to 16-weeks) is a critical period of time when proper socialization should take place, and it is a critical period of time when the puppy may be susceptible to disease. Puppies are especially susceptible to parvovirus (Parvo) which is a life threatening disease that is potentially everywhere in the environment.

Puppy Socialization & Vaccinations

A dog’s personality is mostly shaped in the first four-months of the puppy’s life, so once you bring your puppy home at 8-weeks, you have no time to waste before you start to socialize your puppy. During the next 4 and 8 weeks your puppy’s personality/temperament continues to develop.  After the first 16-weeks it not realistic to think you will change the dog’s personality. Although personality/temperament is consistent and changes very little during the dog’s life if any, behavior can be modified to varying degrees. The importance of early socialization has been widely known since the publication of Scott & Fuller’s research on the social behavior of dogs in the 1960’s.   The Guide Dogs for the Blind Association in England understood the temperamental damage done to puppies that did not get early socialization. They pioneered the idea of early vaccination and early socialization in the 1960’s with great success even in the face of a great amount of criticism from the veterinarian profession. There are still veterinarians today advising owners basically to quarantine their puppy until it completes its full set of vaccinations. The problem with this advice is that of the millions of homes that adopt a puppy each year in the USA, almost half of those dogs will never live to see their second birthday because their owners are unhappy with how they turned out and surrender them to shelters… two out of three will be euthanized.  In the book “Puppy’s First Steps” it states that “puppies that had dysfunctional backgrounds with inadequate socialization were 580 times more likely to end up with fear aggression toward strangers.”

More veterinarians today are now recommending early socialization for puppies as long as appropriate precautions are taken. Dr. R. K. Anderson, DVM, wrote “An Open Letter to My Colleagues in Veterinary Medicine” in 2006 encouraging early socialization after receiving at least the first set of vaccinations and as long as other precautions are followed. Dr. Anderson goes on to state “that the risk of a dog dying (euthanasia) because of behavior problems is more than 1,000 times the risk of dying of distemper or Parvo virus”.  The American Veterinary Society of Animal Behavior (AVSAB) has also come out to state “that it should be the standard of care for puppies to receive such socialization before they are fully vaccinated.”

Go to the Socialization page for guidance.


The rabies vaccination is the only vaccine required by law in most states. The rabies vaccine is important since rabies can be transmitted from dogs and cats to humans and is almost always fatal. The rabies vaccine is the most potent vaccine and is associated with significant adverse reactions. Because “It is medically unsound for this vaccine to be given more often than is necessary to maintain immunity” and overvaccination can cause harmful adverse effects in dogs Dr. Ronald Schultz one of the world's leading veterinary vaccine experts is conducting research (The Rabies Challenge Fund Charitable Trust) at the University of Wisconsin School of Veterinary Medicine to establish that a 3 year booster interval required by state laws may be unnecessary. “The goal of The Rabies Challenge Fund Charitable Trust is to extend the legally required interval for rabies boosters to 5 and then 7 years.

In 2017 the American Animal Hospital Association (AAHA) published its most recent guidelines and recommendations for core and noncore vaccines. Core vaccines are for protection against high risk infectious diseases and these are vaccines the American Animal Hospital Association (AAHA) recommends every dog should have. Non-core vaccines protects from a disease that not every animal may be exposed to. The AAHA states that the “guidelines and recommendations should not be construed as dictating an exclusive protocol, course of treatment, or procedure.” Since every dog does not need every vaccination and giving a noncore vaccine to a dog should be based on risk of exposure, the AAHA developed a Lifestyle-Based Vaccine Calculator that can be used to “develop your dog’s individualized vaccination plan.”

AAHA’s Core Vaccination Protocol (Guidelines)

Vaccine Timing

Beginning as early as 6 weeks of age, administer sequential doses of a combination vaccine at an interval of 2 to 4 weeks until at least 16 weeks of age. Dogs residing in a HIGH-RISK environment may benefit from receiving a final dose at 18 to 20 weeks of age. Administer a single dose of a combination vaccine within 1 year following the last dose in the Initial Vaccination series.

Administer subsequent boosters at intervals of 3 years or longer.

Measuring antibody levels (quantitative or qualitative) provides a reasonable assessment of protective immunity against CDV, CPV, and CAV2.

Core Vaccines

  • Canine Distemper Virus (CDV)

  • Canine Parvovirus (CPV-2)

  • Canine Adenovirus (CAV-2)

Non-Core Vaccines

  • Bordetella

  • Parainfluenza

  • Leptospira

  • Borrelia

  • Canine Influenza H3N8 & H3N2

  • Crotalus atrox (Western Diamondback Rattlesnake)

Dr. Jean Dodds Vaccination Protocol (Guidelines)

Note: New research states that last puppy parvovirus vaccine should be at 18 weeks old.

1 Year After Last Vaccination (Optional Booster)

  • Distemper

  • Parvovirus

If the client decides not to give this optional booster, run a serum antibody titer instead.

If the client intends to just retest serum antibody titers in another three years, this optional booster at puberty is wise to give for more assured protection.

Perform vaccine antibody titers for distemper and parvovirus every three years thereafter, or more often, if desired.

Core Vaccination Protocol

9 - 10 Weeks of Age

  • Distemper

  • Parvovirus

14 – 15 Weeks of Age

  • Distemper

  • Parvovirus

18 weeks of age

  • Parvovirus only

The reason a disinfectant (e.g., alcohol) is not used at the injection site prior to the vaccination is that it may inactivate the vaccine.

Pregnant dogs should not be vaccinated in most circumstances. Vaccines should only be given to healthy dogs. “It is reasonable to avoid administration of any vaccine to patients with a history of systemic disease suspected to be associated with previous vaccination” “or known to be caused by vaccine. [1]


Vaccines should be given based on the needs of an individual dog and not given needlessly. Annual vaccine boosters can “increase the risk of adverse reactions from repeated exposure to foreign substances.” More is not better especially for small breed dogs.[2]  “However, in small companion animals, recent epidemiological data have suggested that the greater the number of components included at one time of vaccination, the greater the likelihood of adverse effects.”  Day, Michael J.; Schultz, Ronald D.. Veterinary Immunology: Principles and Practice, Second Edition (Page 242). CRC Press. Kindle Edition.

“Administration of multiple doses of parenteral vaccine at the same appointment, particularly among small breed dogs (#10 kg), may increase the risk of an acute-onset adverse reaction.”

Instead of administering yearly vaccination boosters, or even every three years a “titer” test can be performed to determine if a revaccination (booster) vaccine is necessary. “most small companion animal infectious viral vaccines currently carry a legal minimum DOI of 3 or 4 years, when in reality the products provide much longer protection (which may be up to the lifetime of the animal).”  (“DOI” – duration of immunity)   Day, Michael J.; Schultz, Ronald D.. Veterinary Immunology: Principles and Practice, Second Edition. CRC Press

A titer test is a simple blood test which measures serum antibodies to determine “the strength of a dog’s immune defenses to a disease to determine that the animal is protected.”  A titer test can be performed a minimum of 3 weeks after the animal has been immunized to determine that it has responded to the vaccination.   “Dogs with a “positive” titer are considered protected.”  Serum antibody titers are used to determine core vaccine immunity in dogs.  (Canine Distemper Virus (CDV), Canine Parvovirus (CPV-2), Canine Adenovirus (CAV-2), and the rabies vaccine) “Research has shown that once an animal’s titer stabilizes, it is likely to remain constant for many years.”  Both Dr. Jean Dodds, and Dr. Ronald Schultz recommend against “vaccinating animals that are already protected because they “may develop a hypersensitivity to vaccine components”.”   Dr. Dodds recommends performing vaccine antibody titers for distemper and parvovirus every three years thereafter or more often, if desired to determine the need if any for a booster vaccination.

Fortunately only a small percentage of vaccinated dogs will develop severe adverse reactions.  But there certain breeds that are more pre-disposed to vaccine-related side-effects.

  • Akita

  • American Cocker Spaniel

  • American Eskimo Dog

  • Dachshund (all varieties, but especially the long-haired)

  • German Shepherd

  • Golden Retriever

  • Great Dane

  • Irish Setter

  • Kerry Blue Terrier

  • Old English Shepdog

  • Poodle (all varieties, but especially the Standard Poodle)

  • Scottish Terrier

  • Shetland Sheepdog

  • Shin Tzu

  • Vizsla

  • Weimaraner

“Breeds with white or predominantly white coats, as well as those with coat color dilution such as fawn (Isabella) or blue Dobermans, the merle coat color, blue Yorkshire Terriers, grey Collies, harlequin Great Danes, and Australian Shepherds are also more susceptible to vaccine reactions.”

Though your dog may not need to visit the veterinarian for an annual booster vaccination after the first year they should still be going for a yearly exam. 

Many have questions about flu virus vaccines. Dr. Dodds has written an article covering the topic. Flu Viruses

Do your own research and due diligence for the well-being of your animals.

Titer Testing Services (Affordable)

Protect The Pets

Rabies (Distemper, Parvo, Adenovirus)


Distemper / Parvo titers

Kansas State Veterinary Diagnostic Laboratory

Core vaccine:  rabies, distemper, parvo and Adenovirus


2017 AAHA Canine Vaccination Guidelines

Dr. W. Jean Dodds Vaccination Protocol of Dogs

Smart Vaccination for Dogs is NOT "Anti-Vaccination"

Many Pet Parents Now Demand This, Saving Their Pets From Potential Agony

Avoid unnecessary vaccines with titer tests (Part III)

2013-2016 Feline Vaccination Protocol - W. Jean Dodds, DVM

Day, Michael J.; Schultz, Ronald D.. Veterinary Immunology: Principles and Practice, Second Edition  CRC Press.

The Dog  Its Behavior, Nutrition, & Health Second Edition   Linda P. Case