Foaming from the dog's mouth does not mean that it will be cured soon, but is a normal vomiting phenomenon caused by the parvovirus. Therefore, it cannot be judged whether the dog's condition is improved by foaming at the dog's mouth. Treatment needs to continue to avoid worsening of the condition. Generally, the fourth and fifth days of parvovirus are when the condition is most serious. If the dog can persevere, it will start to get better on the sixth and seventh days. The dog's spirit, appetite and other aspects will be better at this time. It is necessary to continue the treatment and strengthen the nutritional supplement for the dog to help the dog recover as soon as possible.