Common Dog Vaccine Side Effects

A dog vaccine can sometimes produce adverse side effects. In many cases, a vaccine is simply a strain of the virus modified to allow the dog's immune system to fight and destroy it. The immune system builds antibodies which will fight off any future invasion of this virus, thus rendering the dog "immune" to the virus. However, in this process the dog can sometimes display side effects of the disease or virus itself, and some dogs appear to "get sick" for a day or two after being inoculated.

Common Reactions to Side Effects

Dogs may have a number of side effects to a vaccination. Some are life threatening, so always be cautious when noticing symptoms or unusual behavior, and if you suspect a serious problem, you should contact your vet immediately.

Neurologic Disease and Birth Defects

The canine distemper vaccination is often the most common case of certain neurologic diseases, and it has been linked to certain cases of canine meningitis. Other vaccinations may cause damage to certain parts of the brain, while others still can damage the entire nervous system.

Blue eye, which is an inflammation of the eye, is caused by canine adenovirus-1. However, this is a rare condition, as the use of adenovirus-1 has been replaced by a similar strain, adenovirus-2.

Most vaccinations can also cause birth defects and, because of this, will warn specifically against inoculating pregnant animals, and animals under a specific age. This age differs from breeds, though the general range is four to eight weeks.


Anaphylaxis is a potentially life-threatening allergic reaction that occurs immediately to an ingested or injected substance. It can result in shock, quickly followed by respiratory and cardiac failure. Common onset symptoms include:

  • Diarrhea
  • Vomiting
  • Weak Pulse
  • Facial Swelling
  • Shock
  • Seizures

Anaphylaxis most commonly occurs in killed vaccines, that is, vaccines formed from the dead virus. Leptospirosis and rabies vaccinations use these types.

Increased Allergies

Certain dogs at during the main part of allergy season can sometimes develop more serious allergies. If your dog has allergies, you may want to consider vaccinating him when allergies are not prominent.

Shedding of Vaccine Agent

The shedding of the vaccine agent occurs most commonly when dogs are inoculated intranasally, and the vaccine virus is found in nasal secretions. Other agents, such as the rarely used adenovirus-1, can be shed through the urine.

Generalized Symptoms

Dogs will sometimes appear to "get sick" after receiving a vaccination. They may display any generalized symptoms including:

  • Diarrhea
  • Vomiting
  • Fever
  • Appetite loss
  • Depression
  • Mild coughing
  • Lameness

If your dog displays any generalized symptoms you should still be on alert: more serious reactions such as anaphylaxis can share some of these symptoms, so be sure to ask your vet if you are concerned.

Dog vaccines can sometimes produce adverse side effects when administered. Usually these are not serious, but side effects such as an inflammation of the brain or even anaphylaxis can occur, which can be life threatening.