Immunizing dogs against disease
Seems to be a simple process; pet owners may even take vaccinations for granted. It is both the most routine procedure performed in veterinary clinics and also the one most prone to confusion and misconception.

How does a vaccination work?

In simplest terms, a vaccination stimulates the dog's immune system to protect itself against disease. When the antigen or infectious agent enters the dog's body, it is recognized as foreign and antibodies are produced to bind to it and destroy it. Even though the invader is gone, the cells that manufactured the antibodies "remember" it and will respond more quickly the next time the same agent is confronted.

killed virus vaccines

Each type of vaccine has strengths and weaknesses. Modified-live vaccines provide stronger, longer-lasting, and more rapid protection, including local immunity. They are less expensive and may require only one dose to be effective. They have a potential to become active and cause disease, especially in a patient with a weakened immune system; to create immunosuppression, or to cause abortions in pregnant dogs. Careful handling and storage are required to prevent breakdown of the active ingredients.

Killed vaccines cannot become virulent and are less likely to be immunosuppressive or cause abortions. They remain stable during storage. They are more likely to cause allergic reactions, require more initial injections and more frequent booster shots, and do not produce local immunity.

A good example of the differences between modified-live and killed vaccines is the use of Bordatella vaccinations for kennel cough. Killed vaccines require two injections but are only 60-80 percent effective against disease and don't provide local immunity at the level of the airway. Modified- live vaccines are given intranasally, require only one dose, and start providing local immunity within 48 hours.

How many shots does a dog or puppy need?

There is no one answer for this question, but a few basic rules apply. A minimum of two multivalent vaccinations (including distemper and parvo) given three to four weeks apart are required for every dog or puppy over three months old. An additional vaccination against rabies is also necessary. Vaccinations against coronavirus, Bordatella, or Lyme disease are based on owner's needs and veterinarian's advice.

For young puppies, vaccinations usually start at six-to-eight weeks of age and are given every three-to-four weeks until the puppy is 16 weeks of age. Recent information regarding parvovirus may extend this recommendation to 18 or even 20 weeks, especially for Dobes and Rottweilers.