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. The virus particles can be easily spread on shoes, clothing and other inanimate objects. Fleas, as well as people, can therefore act as indirect sources of infection. Once it gets a foothold in a kennel, it is difficult to eliminate. The disease process begins with the oral ingestion of Parvovirus from the feces of an infected dog.