Vaccination Risks in Dogs

Vaccines have a lot of benefits for canines and protect against numerous viruses, but there are a few vaccination risks that you need to be aware of when you take your pet to the vet.

Side Effects of Canine Vaccines

Nearly all dogs will develop minor side effects after the administration of a vaccine such as:

  • Swelling of the injection site
  • Redness at the injection site
  • Bruising
  • Pain
  • Flu symptoms (i.e. fever, coughing, sneezing, watery eyes and runny nose)

These side effects appear immediately after the administration of the vaccine and should subside within 2 to 5 days.

There are also dogs that may develop more serious side effects which can include:

  • Vomiting
  • Seizures
  • Damage of the central nervous system
  • Kidney damage
  • Liver damage
  • Breathing difficulties
  • Muscular damage

These major side effects are very rare and if they occur, they should appear within 60 days after the vaccines are administered.

Vaccination Risks

There are some risks associated with the administration of canine vaccines. These risks can be:

  • Allergies or anaphylaxis shock
  • Sarcomas and dubious lumps at the injection site
  • False positive tests


Certain dogs may develop allergies to vaccines. This is due to the fact that the immune system won’t react well to the compounds of the vaccine and will cause different symptoms such as:

  • Swelling of the vaccine site, redness
  • Dermatitis
  • Swelling of the feet, face and even respiratory tract (anaphylactic shock), which will hinder the normal breathing

If the dog develops anaphylaxis, he will have to get an injection containing epinephrine, which will reduce the swelling immediately.

If your pet is allergic to several factors, let the vet know when getting the vaccinations. The dog will be kept under surveillance for 60 minutes after each vaccine, as the allergic reactions will develop within a few minutes of the injections.


Sarcomas are lumps that are filled with cancerous cells and have been linked to the vaccinations, as these often develop at the injection sites.

Sarcomas may appear several months or even years after the vaccinations. For this reason, some vets will not recommend yearly vaccine boosters and will only give 1 vaccine every 3 years.

Sarcomas are aggressive and may be surgically removed if not extended, but most commonly the dog will get chemotherapy.

False Positives

Dogs that get certain vaccines can show false positives when a blood sample is analyzed. This is due to the fact that the vaccines contain antibodies that should train the dog’s immune system and make him resistant to a particular virus. These antibodies will be present in the dog’s system and may appear on a blood analysis. This can be problematic, as the vet may not be able to differentiate between a positive and positive.

When a blood sample is taken for analysis, let the vet know about all the vaccines your dog has received.