My one-month-old puppy has had diarrhea for 3 to 4 days; what should I do?

For a puppy with severe diarrhea, fasting is advised, but it must be combined with intravenous fluids at a hospital to supply needed nutrition; otherwise fasting plus diarrhea will surely cause dehydration and low blood sugar. During the fast, appropriate IV fluids solve these problems, and glucose water and sodium salts can be given orally. In addition, test the cause of the diarrhea with a blood count, parvovirus and coronavirus tests, and a fecal exam for internal parasites. Only after confirming the cause can a treatment plan fundamentally solve the problem..