Most dogs (more than 80 percent) that are infected will show no symptoms.[12] Dogs that develop the disease show symptoms of the illness within 3 to 10 days. The symptoms include lethargy, vomiting, fever, and diarrhea (usually bloody). Dogs with CPV are also at risk for intussusception, a condition where part of the intestine prolapses into another part. After a dog is infected, there is no cure, but dogs usually recover from the viral infection and associated symptoms within five days with aggressive treatment.[12] However, diarrhea and vomiting result in dehydration and secondary infections can set in, causing death even in treated dogs. Risk factors for severe disease include young age, a stressful environment, and concurrent infections with bacteria, parasites, and canine coronavirus.[12]
Due to dehydration, the dog's electrolyte balance is destroyed. Because of destruction of the normal intestinal lining, blood and protein leak into the intestines leading to anemia and loss of protein, and endotoxins escape into the bloodstream, causing endotoxemia. The white blood cell level drops, further weakening the dog. Any or all of these factors can lead to shock and death.
according to wikipedia... i would just hope that if my dog was infected she would be in the 20 percent that do show symptoms.