Parvovirus is capable of causing two different sets of clinical problems. Any age, breed or sex of dog could be affected by Parvovirus. However, infection with Parvovirus does not automatically mean illness. Several factors such as age, environment, stress, parasites and general health status of each individual dog infected could affect the severity of illness. The degree of illness could range from very mild and not apparent, to very severe, often resulting in death.
Experts agree that canine Parvovirus is closely related to Parvoviruses that affect other animals.
Where the virus originally came from remains unknown, but it is possible that it is a mutant from another Parvovirus that affects other species of animals. Man is not known to be affected by canine Parvovirus. Since its first appearance in 1978, canine Parvovirus has spread to every continent in the world, probably the result of the hardy nature of the virus. Direct transmission occurs when an infected dog comes in contact with a healthy dog. The virus is found in heavy concentration in the infected dog's stool.