The reasons why this happens are: 1. The dog's stomach is not good, eating too fast, eating a lot, and feeling pressure in the stomach, so it vomits; 2. The dog eats spoiled or inedible food, causing vomiting. None of the above situations are serious, and the breeder only needs to feed them gastrointestinal medications. If your dog vomits repeatedly and is accompanied by loss of energy and mental decline, it may be that there is a disease in the body, and it is recommended to send it to the doctor for examination.