Routine puppy vaccinations against Parvovirus and Distemper virus are essential to ensuring your puppy’s health. Puppies are initially protected against these viruses through the antibodies they received from their mother. However, as the mother’s antibodies begin to fade, puppies become susceptible to infection. There is a window of susceptibility during which time the mother's antibodies are no longer effective, but they are still too high to allow your puppy to develop his own protection. For most puppies, this window is open between 8-12 weeks of age. Therefore, it is extremely important to keep your puppy away from environments where he could possibly be exposed to the virus until he has received a full round of vaccines.
Most veterinarians recommend your puppy receives his first set of vaccines at approximately 6-8 weeks of age. Then he should receive a booster every 3-4 weeks until he reaches 16 weeks of age. This will ensure he receives the full round of vaccines and has developed his own protection by time his mother's antibodies are no longer effective
Parvovirus and Distemper virus are both found throughout the environment and can survive for long periods of time in the soil. It is imperative that you keep young unvaccinated puppies away from any yards where there was a known positive puppy for at least one year.
Both of these viruses cause severe intestinal distress. Basically, they cause the intestines to shed their lining. The intestinal lining consists of the cells that absorb water and nutrients out of the intestines. Therefore, the puppy ends up losing a lot of water (i.e. diarrhea) and losing a lot of weight due to the inability to absorb nutrients. The shedding of the intestinal lining is also very painful. Many puppies, especially small breeds, do not survive this loss of water and nutrients.
If you choose not to vaccinate your puppy and they survive puppyhood, their odds of contracting the viruses do decrease significantly. However, unvaccinated adult dogs can still become infected with both Parvovirus and Distemper virus.