Owners should pay attention to this situation. Generally, the cause of dogs foaming at the mouth is gastrointestinal inflammation. If the dog is not in good spirits, vomits repeatedly and stops eating, it is probably in a state of acute gastroenteritis. Owners should Purchase the corresponding medicine to treat your dog. Do not feed the dog any food during this period to keep the dog in a fasting state and reduce gastrointestinal discomfort.