Pathogenesis of this symptom are inflammation of gastrointestinal epithelium. Virus can attack the epithelial cells that form villi so surface for absorption nutrient in bowels is decreased and also include bleeding. The follower are dehydration and malabsorption. Food and water entering the bowels will accumulate in its lumen. In this condition puppy will die shortly.
Survival depend on type of virus and condition of disease.
If dog infect Corona virus, it will spontaneous heal. But this is contrast in the case of Parvo virus. Dog should be taken to the veterinarian for supportive therapy. Occurrence are less than gastroenteritis. It is seen only in less than 2 months puppy, because the heart cell or myocardium of puppy still dividing.