Cause
Parvovirus is transmitted from an infected dog to another dog most commonly through the fecal-oral route. The virus is shed in the feces typically for two weeks following infection. However, once the virus is within the environment, it can remain infective for months. Highly contagious, parvovirus can infect any dog that enters a contaminated area and has not had proper vaccinations. Some dogs do not develop symptoms of parvovirus; instead, they are carriers of the disease, shedding infective feces for a year or more.