Vaccinations for dogs are an important step to building a healthy immune system. It is possible, however, for some vaccines to fail, causing the dog to contract a disease. Here are some reasons why these vaccines for dogs can fail to prevent disease:
- Maternal antibodies: Puppies have antibodies that have been passed on from its mother through her milk to help prevent infection and disease. For up to 14 weeks, these puppies may have too many antibodies to allow a vaccine to work efficiently. At the same time, the puppy may not have enough maternal antibodies to fight off infection. This time period is known as the window of susceptibility.
- Poor immune systems: Dogs with immunosuppression due to previous medical treatments like chemotherapy, or have a disease that weakens the immune system, generally have less effective reactions to vaccinations.
- Live vaccines: MLV or modified live virus vaccines can cause the disease it should be vaccinating against to become active in puppies or dogs with weak immune systems.
- Poor environment: Stressful physical surroundings like a crowded kennel or high temperatures and humidity, which raises a puppy's body temperature, can prevent effective vaccinations.
Failure of vaccine: If a vaccine is mishandled or improperly stored or administered, a vaccine may fail. - Time between vaccinations: Vaccines that are administered too closely at a time or too far apart can cause either blockage of antibodies or failed immune response stimulation.