Canine parvovirus, or parvo, is a highly contagious viral disease. This tough virus, which mainly affects a dog's intestinal tract and can be life-threatening, is able to live in the environment for months. The virus also can survive on inanimate objects, like the soles of shoes, and be carried on them to other locations.
How Parvovirus is Spread
Canine parvovirus can be spread by a person, dog or object that has been in contact with infected stools. An infected dog sheds parvo in his feces for about two weeks after exposure to the virus. He can shed 35 million viral particles -- a typical infectious dose for an unvaccinated dog is 1000 particles -- in an ounce of stool. The virus can survive outdoors in shady areas for seven months and in sunlit spots for five months, even during freezing temperatures. Parvovirus can be transported on a dog's hair and feet, or on someone's shoes and clothes. Wendy C. Brooks, DVM, DipABVP, believes this accounts for how quickly parvovirus spread throughout the world when the disease first appeared in the late 1970s. Puppies 6 weeks to 6 months old, along with unvaccinated or partially vaccinated dogs are the most vulnerable to infection. If you think you have walked in a contaminated area, soak the soles of your shoes for at least 10 minutes in a solution of one part bleach to 32 parts water to kill the virus.