A Critical Look at Pet Vaccination Through Science, Immunology, and Ethical Practice

By Times R. Bodi

For Thriving Pets

For decades, pet owners have been told that routine vaccinations are essential for maintaining animal health. Annual shots are promoted not just as beneficial but as necessary. Yet a growing body of veterinary professionals, immunologists, researchers, and pet advocates now argue that this long-standing practice may be outdated, unnecessary—and in many cases, dangerous.

This isn’t about “over-vaccination” anymore. It’s about asking whether routine vaccination at all, after an initial core series, is appropriate or safe. The truth is that the scientific foundation for frequent and lifetime revaccination in dogs and cats is not nearly as sound as most people think. The fallout from this overuse may be far greater than the veterinary industry is willing to admit.

The Case for Stopping Routine Vaccination

Immunologist Dr. Ronald D. Schultz, Professor and Chair of the Department of Pathobiological Sciences at the University of Wisconsin-Madison, has long been one of the leading researchers in veterinary vaccine science. His studies dating back to the 1970s showed that immunity from core vaccines lasts for many years—often the life of the animal—without the need for repeated boosters. According to his research, the minimum duration of immunity (DOI) for canine distemper, parvovirus, and adenovirus after the initial puppy series is 7 to 15 years, often lifelong.

Dr. Schultz’s findings led to the 2003 American Animal Hospital Association (AAHA) Canine Vaccine Guidelines, which finally acknowledged that annual vaccination is unnecessary. Despite this, most veterinary practices continued to recommend yearly or triennial boosters—often driven more by economic factors than by medical necessity.

Industry Influence and Incomplete Education

A startling number of veterinarians have spoken out about their own lack of formal education regarding vaccination risks and immunology. Many admit they were taught vaccine schedules as unquestionable dogma—with little to no critical examination of safety, immune system consequences, or adverse reactions.

Veterinarians such as Dr. Stephen Blake, Dr. Patricia Jordan, Dr. Christina Chambreau, and Dr. Michael Dym have all stated unequivocally that their veterinary training failed to educate them on the deeper science of vaccine safety or duration of immunity.

“Vaccines were taught as safe and necessary, and that was it,” writes Dr. Blake. “We were not told about mercury or aluminum in vaccines, or that they can trigger autoimmune disorders, cancer, and neurological damage.”

Dr. Jordan is even more blunt: “We had no training on vaccination. Those teaching us didn’t know either. Ron Schultz says vet med doctors should not be making vaccine recommendations—they aren’t educated enough in vaccinology or immunology to do so.”

This sentiment is echoed by more than 20 veterinary professionals, including:

• Dr. Karen Becker, DVM — A globally recognized advocate of species-appropriate wellness, known for her outspoken stance against unnecessary medical interventions.
• Dr. Ronald Schultz, PhD — Veterinary immunologist whose decades of research proved core vaccine immunity often lasts a lifetime.
• Dr. Jean Dodds, DVM — Founder of Hemopet and vaccine researcher who helped expose the links between vaccination and autoimmune disease.
• Dr. Patricia Jordan, DVM — Author of Vaccinosis: The Mark of the Beast, sharply critical of vaccine-related chronic illness in animals.
• Dr. Judy Jasek, DVM — Integrative cancer vet who ties tumor development to immune dysfunction following vaccination.
• Dr. Michael Dym, VMD — Former mainstream vet turned homeopath who publicly warns of widespread vaccine injury.
• Dr. Christina Chambreau, DVM — Early holistic vet and educator emphasizing immune support over injection schedules.
• Dr. Stephen Blake, DVM — Known as “The Pet Whisperer,” he abandoned all vaccines decades ago after witnessing extensive harm.
• Dr. Arthur Freedman, DVM — A holistic practitioner who documents dramatic health turnarounds post-vaccine cessation.
• Dr. Ronna Kabler, DVM — Vocal critic of standard vet protocols, citing personal and professional experience.
• Dr. Ihor Basko, DVM — Hawaiian-based vet promoting detox, raw feeding, and vaccine avoidance for true health.
• Dr. Marcia Martin, DVM, CVA — Integrative vet who treats vaccine damage through acupuncture and homeopathy.
• Dr. Erin Zamzow, DVM — Strong proponent of titer testing and minimalism in veterinary intervention.
• Dr. Dorothea Hofman, BVSc — Critic of pharmaceutical dominance in animal health, advocating personalized care plans.
• Dr. Melissa Shelton, DVM — Founder of animal-focused essential oil therapy, refuses to vaccinate her own animals.
• Dr. Judy Morgan, DVM — Author, speaker, and holistic leader who describes routine vaccination as “one of the most dangerous practices in veterinary medicine.”
• Dr. Peter Dobias, DVM — Strong public voice for natural immunity, detoxification, and stopping the vaccine cycle altogether.
• Dr. Nick Thompson, BVM&S, VetMFHom, MRCVS — UK-based vet and founder of the Raw Feeding Veterinary Society, long-time critic of annual boosters.
• Dr. Conor Brady, PhD — Canine nutrition researcher whose work uncovers the deep impact of immune disruption through vaccines.
• Dr. Barbara Royal, DVM, CVA — President of the Royal Animal Health University, who emphasizes natural medicine over pharmaceutical dependence.
• Dr. Barbara Fougere, BVSc, CVA, CVBM, PhD (cand) — Global authority on veterinary botanical medicine and vaccine-free protocols.
• Dr. Kate Marsden and Dr. Steve Marsden — International teachers of holistic vet medicine, advocating for the removal of unnecessary medical interference in animals.

And the list goes on—growing longer every year. More and more veterinarians are speaking out, leaving behind outdated protocols, and embracing a radical but evidence-based truth:

Not vaccinating may be the most intelligent, ethical, and scientifically sound choice for long-term animal health.

Many of these vets report seeing first-hand in clinical practice what they believe are vaccine-related illnesses including autoimmune disease, epilepsy, inflammatory bowel disease, and skin disorders—often occurring weeks or months after injections.

What the Research Says

There is a robust collection of peer-reviewed literature detailing the risks associated with vaccination:

• Autoimmune Disease: Numerous studies have connected vaccines with immune-mediated hemolytic anemia (IMHA), immune thrombocytopenia (ITP), and autoimmune thyroiditis.
  
  • See: Dodds WJ. Adv Vet Sci Comp Med. 1983; Schultz et al. Vet Med. 1998; Duval and Giger. J Vet Intern Med. 1996.
• Neurological Reactions: Modified live virus (MLV) vaccines have been shown to induce seizures, polyneuropathy, and even encephalitis in genetically susceptible animals.
  
  • See: Dodds WJ. Adv Vet Med. 1999; Tizard I. J Am Vet Med Assoc. 1990.
• Cancer: Injection-site sarcomas, long known in cats, are now increasingly reported in dogs as well.
  
  • See: Vascellari et al. J Vet Med. 2003.
• Endocrine Disorders: Vaccination has been linked with development of autoantibodies against the thyroid gland, a precursor to hypothyroidism.
  
  • See: Scott-Moncrieff et al. J Am Vet Med Assoc. 2002.
• Immune System Suppression: Paradoxically, some vaccines temporarily suppress the immune system, making animals more vulnerable to infection.
  
  • See: Phillips et al. Can J Vet Res. 1989.

Veterinary vaccine researcher Dr. W. Jean Dodds—whose work spans over 40 years—has detailed clinical signs of vaccine reaction in animals: fever, joint pain, malaise, seizures, and autoimmune flare-ups. She warns that these symptoms often emerge not within hours but weeks or even months post-vaccination, making causation easy to overlook.

The Ethical Void: Informed Consent

In a 2004 article published in the Journal of the American Veterinary Medical Association, authors Flemming and Scott stress that informed consent is essential in all medical decisions—including vaccination. Clients deserve to know that vaccines, like any pharmaceutical product, carry risks—especially when administered repeatedly and unnecessarily.

Yet many clinics do not inform clients of alternative approaches like antibody titer testing, vaccine detox protocols, or exemption based on genetic risk.

Titer Testing: The Forgotten Tool

Titer testing measures antibodies in the bloodstream to determine if an animal is still immune. For core diseases like parvovirus and distemper, protective antibody levels often remain for life after the puppy series.

A 2000 study by Twark and Dodds demonstrated that more than 95% of dogs tested still had adequate titers several years after initial vaccination, making further shots redundant.

“Titer testing is the gold standard for determining immunity,” says Dr. Ronald Schultz. “There is no scientific justification for automatic boosters in animals with confirmed immunity.”

Pushing Back Against Pharmaceutical Pressure

The veterinary pharmaceutical industry is a multibillion-dollar sector, and vaccines remain one of its most profitable products. Many veterinary colleges, journals, and continuing education seminars receive sponsorship from these same corporations—raising obvious conflicts of interest.

As Dr. Dodds wrote in her white paper, More Bumps on the Vaccine Road:

“There is a massive marketing effort behind vaccination. We, the professionals, must filter and question the data—not just pass it along. Our oath is to ‘do no harm.’ That must come before profits, fear, or routine.”

Where Do We Go From Here?

It’s time to rethink our blind trust in vaccine schedules. It’s time to question whether the annual shots we’ve accepted as “care” are sometimes causing the very illnesses we seek to prevent.

A growing movement of veterinary professionals—both conventional and holistic—are now urging an end to routine revaccination and instead promoting:

• A minimal vaccine protocol—only the puppy/kitten series, with carefully timed doses.
• Use of titer testing instead of automatic boosters.
• Exemptions for animals with chronic conditions or genetic predispositions.
• Public education on the real risks and duration of immunity.
• Greater accountability and regulation in the veterinary pharmaceutical industry.

Final Thoughts

Choosing not to vaccinate beyond an initial series may seem radical—but in light of the evidence, it is often the most cautious, science-based, and ethical path. Doing less can mean doing better.

As pet parents, we are not merely consumers of services—we are advocates for the lifelong health and safety of the animals in our care. And we have both the right and the responsibility to ask:

What if we’re getting it wrong?

Sources & References (condensed for readability; full list available on request):

1. Dodds WJ. Adv Vet Sci Comp Med. 1983.
2. Schultz RD. Vet Med. 1998.
3. Twark L, Dodds WJ. J Am Vet Med Assoc. 2000.
4. Phillips TR et al. Can J Vet Res. 1989.
5. Vascellari M et al. J Vet Med. 2003.
6. Scott-Moncrieff JC et al. J Am Vet Med Assoc. 2002.
7. Tizard I. J Am Vet Med Assoc. 1990.
8. AAHA Guidelines. 2003.
9. WSAVA Guidelines. 2023.
10. Dogs Naturally Magazine Archives.