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Dog vaccine side effects are something that many dog owners may be concerned about. What should dog owners expect after vaccinating their dogs? How likely are dog vaccine side effects to occur? How long after the vaccine may they occur? 

These are many questions dog owners may wonder about. 

While vaccine side effects can be scary, the truth is that they are quite rare.

Veterinarian Dr. Ivana Crnec provides information about dog vaccine side effects and weighs in on the importance of vaccinating dogs from serious infectious diseases which can even prove to even be life threatening.

dog vaccines

What are Some Dog Vaccine Side Effects?

With the constantly increasing popularity of the anti-vaccination movement it is only logical for first-time dog parents to be suspicious whether or not they should vaccinate their dogs.

 But is this movement’s core aim based on science?

 More and more vets around the world are facing the beguiling question – Can this vaccine give my dog autism? 

Well, the simplest answer is no – dog vaccines cannot give dogs autism. In fact, autism does not even exist among dogs!

According to pro-vaccine experts and vets, dog parents who decline vaccination against contagious diseases with high mortality rates are sentencing their dogs to death. However, although vaccines cannot give dogs autism, sometimes they do cause certain side effects.

Although rare, these side effects are definitely worth mentioning. Keep in mind that the side effects are not mentioned as a reason not to vaccinate your dog. They are both mentioned and described to prepare you for what you can expect after having your dog vaccinated.

Common Dog Vaccine Side Effects 

Did you know? Based on past studies and observations, side effects or adverse reactions are quite rare (occur in less than 1 percent of all cases). Nevertheless, here is a list of the potential dog vaccine side effects.

Common Side Effects 

The below vaccine side effects in dogs are the most commonly observed. They usually appear within hours of the vaccine administration and last for up to two days.

  • Lethargy
  • Mild fever
  • Decreased appetite
  • Discomfort at the injection site

 It should be noted that these side effects can be expected in young puppies receiving their first or second vaccine. Older dogs are unlikely to manifest any of the above stated symptoms.

Respiratory Issues

Sometimes the administration of intranasal vaccines can be followed by several respiratory symptoms such as:

  • Sneezing
  • Mild coughing
  • Runny nose
  • Runny eyes

The above listed respiratory signs may develop 2 to 5 days after the dog receives an intranasal vaccine and can last for up to a week.

Local Reactions

The most commonly observed local reactions at the injection site include the following:

  • Pain
  • Swelling
  • Redness
  • Irritation
  • Abscesses
  • Hair loss
  • Hair color change
  • Granulomas or hard tissue (rare)

 These side effects can develop between minutes to 1 week after the vaccine administration. Although the local reactions can be treated symptomatically, they usually resolve on their own.

Fibrocarcinomas at The Injection Site

Although more popular among cats, fibrocarcinomas are equally present among dogs. It should be well-noted that fibrocarcinomas can appear in places other than the vaccine administration site. 

In a nutshell, fibrocarcinomas are caused by the aluminum found in most vaccines.

If a macrophage (immune system cell) carries the aluminum away from the injection site, the fibrosarcoma will develop wherever the aluminum is carried.

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Rarely, vaccines can cause a potentially life-threatening reaction known as anaphylaxis. As a condition, anaphylaxis causes both cardiac and respiratory failures which usually develop within minutes of receiving the shot. 

The most common symptoms of anaphylaxis include:

  • Elevated heart rate
  • Difficulty breathing
  • Pale gums
  • Vomiting
  • Diarrhea
  • Seizures
  • Hives
  • Swelling of the face.

Dogs that develop anaphylaxis are considered an emergency and require epinephrine administration as well as symptomatic treatment after stabilization.


It has been shown that vaccination can potentially damage the immune system. Since allergies can be defined as improper immune responses, it can be concluded that there might be a link between vaccination and allergies. 

This is because most vaccines contain aluminum and the aluminum causes an up-regulation of the allergy immunoglobulin called IgE. 

Allergies are a chronic disorder and usually require life-long management.

Autoimmune Hemolytic Anemia

Some dogs vaccinated with modified live multiple antigen vaccines (specifically parvo) may eventually develop autoimmune hemolytic anemia (AIHA).

 Although AIHA can be caused by many factors, vaccination can trigger production of antibodies against red blood cells. 

Dogs with AIHA will show the following signs and symptoms:

  • Weakness
  • Lethargy
  • Decreased appetite
  • Exercise intolerance
  • Difficult breathing
  • Increased heart rate
  • Vomiting

AIHA is a life threatening condition that requires lifelong and complex management (including fluids, steroids and blood transfusions).

Reproductive System Issues

Using modified live vaccines in pregnant dogs can lead to a variety of problems ranging from prenatal infections and fetal malformations to infertility and even abortions.

Neurological Disease 

Dogs that received a live virus rabies vaccine may develop a vaccine-induced form of rabies. The vaccine induced form of rabies develops 10-21 days after receiving the vaccine.

 These dogs get serious infection of the brain or spinal cord and the neurological signs vary based on what part of the nervous system is infected. 

Unfortunately, the condition can only progress and it cannot be cured. On the bright side, this side effect is extremely rare.

Blue Eye" Phenomenon

The popular term "blue eye" indicates diffuse clouding of the eye that develops after vaccination with live modified canine adenovirus type 1. 

The condition has sudden onset but usually resolves on its own. The Afghan hound is particularly prone to developing this side effect.

In Conclusion

With everything being said, it can be assumed that vaccines are not 100 percent harmless. However, more often than not, the pros of vaccination outweigh the cons.

 As previously mentioned, side effects do exist but they are quite rare and not significant enough to avoid vaccines.

Vaccines prevent highly contagious and deadly diseases. Some of those diseases are even transmitted to humans.

 According to CDC, each year around the world nearly 60.000 people die from rabies. Over half of the deaths occur in children and in areas where stray and pet dogs are not routinely vaccinated against rabies. 

With more and more dog parents challenging the need to vaccinate their dogs, it is more important than ever to accent that by protecting our canine babies we indirectly protect ourselves too.

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