Parvo virus was first identified in 1978 and within two years' it had spread all over the world. Over the years, the parvo virus has mutated into two different strains and there is evidence of a third strain present in Italy, Spain and Vietnam. Every case of canine parvo virus, or CPV, comes from the first two strains. Every different species has its own parvo virus and it cannot be spread outside of the species, so there is a human parvo virus, a canine parvo virus, a feline parvo virus, and so on.

Even though the virus cannot be spread from a cat to a dog or from a bird to a cat, they can spread the virus through contact. For instance, your cat wanders through the neighbor's yard and picks up the virus on her feet she can then bring it into your home potentially infecting any canines on the property.

The parvo virus works in two ways either through the intestines or through the heart. When a dog gets an intestinal infection, it is picked up by the animal through oral contact with contaminated feces. Simply put, your dog would have to come into contaminated feces from another dog. The intestinal dog parvo symptoms occur when the virus attacks the bone marrow, rapidly dividing cells in the intestinal crypts and the lymph nodes. This allows normally occurring bacteria from the intestines to enter the blood stream to make the animal septic. The virus can be shed in the stool for up to three weeks thus making this a very contagious disease for pets that have not been inoculated.

The cardio form of the infection is most often seen in puppies that are infected in utero or shortly after birth. It must be noted that the cardiac form of CPV is less common since the mother usually passes immunity on to her pups from birth. The virus will attack the heart in the infected pup and result in death shortly thereafter.

Dog parvo symptoms usually present themselves within 3 to 10 days of contact. They include the following: lethargy, vomiting, fever and diarrhea. The diarrhea can cause severe dehydration and secondary infections. The dog will not usually die from the virus but from a secondary infection.

The survival rate depends upon how swiftly parvo virus is diagnosed and treatment is begun. If the virus is not caught early on, the usual treatment is given through an IV line in which fluids are pushed to re-hydrate the puppy or dog more quickly. In addition to giving fluids, anti-nausea and antibiotic shots may be given intramuscularly. Given the proper care, the prognosis is good, but if care is withheld your dog will die prematurely. Most vets will strongly suggest that your pet be vaccinated against parvo about eight weeks after a puppy is weaned.