What is wrong with a dog suddenly vomiting very thick white foam

The causes of vomiting are physiological vomiting and pathological vomiting. Physiological vomiting is caused by excessive secretion of gastric acid that irritates the gastric mucosa after a long period of not eating, resulting in nerve irritation. This condition can be improved by eating. A small amount of easily digestible liquid food should be fed at first, and then the amount of food should be increased as you recover. However, this is most often seen with pathological vomiting. If the above does not improve or if other abnormal symptoms appear, seek medical attention. Vomiting may be caused by infections, obstructions, ulcers or mucosal lesions in the digestive tract.