Parvoia in dogs with brown and loose stools is not detoxification. It is a case of blood in the stool. It is usually more common in the middle and late stages of parvovirus, and it will also be accompanied by a fishy smell. Once discovered, timely treatment is required. Parvovirus is a relatively common infectious disease in dogs. If it is discovered and treated in time, there is a great hope of cure. If the dog can persist for five to seven days, it will begin to slowly improve.