What happens if a dog gets vaccinated twice?

When the dog receives more than one dose of the vaccine, can he have health problems? To answer that question, this blog article will talk about vaccines for dogs and their importance in protecting the health of animals.

What happens if a dog gets vaccinated twice?

Vaccines are effective and safe. But when in excess they can bring harm to the animal’s health. Each vaccine is unique with individual effects. So if an animal has taken more than one dose of Vaccine it should be under observation by a Veterinarian.

Some studies already show that over a long period, excess vaccines in dogs can result in health problems like allergic processes, autoimmune diseases, tumors, polyarthritis, chronic kidney disease and others. So, Vaccines should not be given unnecessarily, as they can cause adverse reactions.

Why are vaccines important?

Vaccination is important to keep your dog safe from disease. Vaccines are produced from attenuated bacteria or viruses. They have the function of inducing the body to produce antibodies that are responsible for defending the body in case of infection.

Without vaccination, animals are vulnerable to diseases that can be lethal to animals. Even if not vaccinated as a puppy, the adult dog must be vaccinated, because then he will produce antibodies that will protect him when he comes into contact with pathogenic microorganisms.

Dog vaccine schedule

The recommendation is for initial basic vaccination at 6-8 weeks of age and booster vaccination thereafter every 2-4 weeks until 16 weeks of age. Thus, becoming a revaccination (booster) at either 6 months or one year of age, then not more often than every 3 years. Except for the rabies vaccine, which must be applied in a single dose after 12 weeks of life and the booster must be annual depending on the country.

For adults two doses 2-4 weeks apart are recommended with a booster in one year, then not more often than every 3 years. For rabies a single dose must be applied, and the booster must be annual depending on the country.

What vaccines prevent it?

Vaccines can be considered core and non-core. Core vaccines are those that protect against diseases endemic to a region, those with potential public health importance, required by law, virulent/highly infectious and/or those that pose a risk of serious disease.

Currently, the Dog Core vaccines are those that provide protection against infection with canine distemper virus, canine adenovirus, rabies, canine parvovirus type 2 and their variants.

Main diseases to be prevented by vaccines:

  • Canine Distemper: viral infection that mainly affects the nervous system;
  • Canine Adenovirus: Adenovirus type 1 causes liver damage and can lead to hepatitis, whereas adenovirus type 2 causes respiratory symptoms that can progress to pneumonia.
  • Rabies: Lethal viral infection that mainly affects the nervous system;
  • Canine Parvovirus: causes intense, bloody diarrhea, which can lead to dehydration.

Non-core vaccines are those that depend on the risk of exposure of the dog, as is the case of Leptospira sp., Bordetella bronchiseptica, Borrelia burgdorferi, Giardia sp, and others.

Canine Distemper

Distemper is a canine viral infection that mainly affects the nervous system, the disease is transmitted by secretions such as urine and feces. Dogs with distemper may have several symptoms including apathy, weight loss, diarrhea, vomiting, eye and nasal secretions, seizures, loss of limb movement.

The chances of surviving distemper are very low, and the animals that survive are usually left with sequelae. Thus, it is an animal that needs more attention throughout its life.

Canine Adenovirus

Canine Adenovirus can be divided into two subtypes. Type 1 adenovirus causes liver damage and can lead to hepatitis, while type 2 adenovirus causes respiratory symptoms that can progress to pneumonia.

Canine adenovirus transmission occurs through contact with secretions from infected animals. And most common symptoms of adenovirus are fever, diarrhea with or without blood, weight loss. Treatment can be effective, but animals can die from opportunistic infections.


Rabies is a lethal viral infection that mainly affects the dogs nervous system. After presenting symptoms, dogs can die within 10 days. Rabies is transmitted mainly by saliva in the bites of dogs, cats and bats.

Rabies is a zoonosis, meaning it can be transmitted to humans. Therefore, the animal should always be vaccinated. And in case of a bite from abandoned dogs, humans should seek medical attention as soon as possible.

Canine Parvovirus

Canine parvovirus is a viral disease whose main symptom is intense and bloody diarrhea, vomiting, fever and weight loss. Parvovirus mainly affects puppies and is transmitted orally.

Diarrhea and vomiting can lead to dehydration, which leads to the animal’s death. Some animals may survive treatment while others may have complications from opportunistic infections that can lead to the death of the puppy.


In this blog post we were able to learn more about vaccinating dogs, why they are important. We were able to learn that vaccines are safe and effective, but vaccinations should not be exceeded as they can harm the dog’s health.

Frequently Asked Questions (FAQs): dog vaccine schedule

What vaccines are required for dogs?

All the core vaccines are required, as parvovirus, distemper, canine adenovirus and rabies. Non-core vaccines (Leptospira sp. Bordetella bronchiseptica, Borrelia burgdorferi) are given depending on the dog’s exposure risk.

Do dogs really need to be vaccinated?

Yes, Dogs should receive core vaccines (Parvovirus, Distemper, Canine adenovirus and Rabies) and may need others depending on their lifestyle.

What happens if my dog is not vaccinated?

If dogs aren’t vaccinated, they will be vulnerable to diseases such as rabies, canine distemper, canine adenovirus, canine parvovirus and others.


Day, M. J., Crawford, C., Marcondes, M., & Squires, R. A. (2020). Recommendations on vaccination for Latin American small animal practitioners: a report of the WSAVA Vaccination Guidelines Group. Journal of Small Animal Practice, 61(6), E1-E35.

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