Before administering any medication, it’s crucial to determine the severity of your dog’s condition. While occasional bouts of diarrhea may not be alarming, persistent diarrhea lasting more than a day, especially when accompanied by vomiting, lethargy, or blood in the stool, warrants a trip to the veterinarian. In some cases, diarrhea may indicate a more serious underlying issue, such as infections, parasites, or a systemic illness.