Allergic Reactions in Dogs to Vaccinations

An adverse or allergic reaction is possible with any type of foreign substance that enters the body. Vaccines are no exception. On rare occasions, substances that are meant to aid in the body's defense against viral invaders work against the body to cause painful, and sometimes life-threatening, side effects. In veterinary medicine, postvaccinal adverse reactions are required to be reported to both the manufacturer of the vaccine as well as the U.S. Pharmocopeia Veterinary Practitioner's Reporting Program.

  1. Types of Vaccinations

    • There are four main types of vaccinations in the veterinary world - modified live virus (MLV or attenuated) vaccines, bacterin vaccines, killed virus vaccines, and adjuvenated vaccines. MLV vaccines have shown, over time, to cause more allergic reactions among dogs than the others.

    Mild Symptoms

    • Mild symptoms, or those that are not life threatening, include but are not limited to pain, swelling or itching at the site of injection. Hives, facial edema and swelling of the dog's eyes may also be present. A mild fever may persist for one to two days following the receipt of a vaccination.

    Treatment for Mild Symptoms

    • Mild symptoms are treated via a follow up visit to the veterinarian. An antihistimine may be administered orally or applied in the form of a cream to the skin. Pain relief medication may be offered as well.

    Severe Symptoms

    • Symptoms of shock may be observed in some animals. While dangerous, this usually passes. The most severe symptom to occur is anaphylaxis. Anaphylaxis is the immediate swelling of the airways and may result in respiratory arrest, cardiovascular collapse and death within 30 minutes of the administration of a vaccine.

    Treatment of Severe Symptoms

    • Since anaphylaxis is an immediate reaction, a veterinarian my pursue one or more courses of treatment in order to save the dog's life. The administration of an antihistimine or a small dose of corticosteroids serves to relax airways. Epinephrine, a chemical similar to adrenaline, may be administered. Intravenous (IV) fluids may also be indicated, as well as life support.