How Dogs Become Infected


CPV is now found in most regions of North America. The virus is extremely hardy as it is a "naked" virus. Strong cleaners such as bleach must be used as a disinfectant. Areas where many dogs gather such as dog parks, kennels, dog shows and veterinary hospitals are sites were potential infection may occur. Maternal anti-bodies, if the mother has had previous exposure, should protect the puppies until around 6-8 weeks of age. In some cases maternal anti-bodies have been present up to 14 weeks of age.1  In utero infection of the puppies does not result in congenital defects like those seen in kittens with Feline Panleukapenia.

 Feces from an infected animal is the most likely source of infection. Clinical signs generally appear 3-7 days following exposure.2 The virus has a predilection for actively dividing cells therefore the intestine is often the main site of infection. In young animals the heart or thymus are also possible sites. In the intestine the virus attaches to the villi and may cause villus necrosis and blunting.2 Damage to the villi contributes to the diarrhea and fluid loss in infected animals. 
The virus is shed from infected animals in the feces. Animals that have been infected should be kept in isolation from other dogs for seven days after clinical signs have disappeared. In a few cases, animals that are immunocompromised will shed virus for several weeks to months following infection, indicative of their inability to mount an immune response. Animals that have become infected and have a healthy immune system appear to have lifelong immunity and should not develop the disease again.


1 Claws and Paws Veterinary Hospital. "Parvovirus". 2007
Available at

 2Mar Vista Animal Medical Centre. "Parvovirus". 2004.
Available at