Wyatt Earp speaking of Doc Holliday. Doc Holliday's father, Henry B. Holliday was a trained pharmacist who served in several wars, including the Cherokee Indian War, the Mexican War, and as a Major in the Confederate Army.
Dogs frequently eat grass to ease stomach discomfort. If your dog's stomach is empty, the grass may cause your dog's stomach to produce more digestive enzymes, and this can result in vomiting bile. Unless your grass is treated with fertilizer or pesticides, it's generally safe to allow your dog to continue eating it, as it can help ease her stomach problems.
Yet another reason dogs vomit white foam is because of kennel cough, which is an upper respiratory infection that is contracted from other dogs. Dogs suffering from kennel cough have a dry cough and experience flu-like symptoms, such as nasal discharge, sneezing and fever. Finally, vomiting white foam is a sign of rabies as well. The foaming around the mouth is caused by nerve damage around the mouth and throat, which prevents the dog from swallowing.