Foaming in dogs may be caused by gastroenteritis, improper diet, poisoning, gingivitis, or tonsillitis. It needs to be judged based on the specific situation of the dog. If the dog suddenly eats something, If the dog is foaming at the mouth and accompanied by convulsions, the possibility of poisoning is relatively high; if the dog does not have other abnormalities and returns to normal after vomiting, it may be caused by improper diet and other reasons.