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.
Giardia is also a common intestinal parasite that may cause vomiting, as well as blood in the stool. If the stool check is negative, other causes of blood in the stool should be explored including dietary indiscretion, ingested foreign bodies, dietary allergy, inflammation of the liver and inflammation of the pancreas. Viral and bacterial infections may also cause bloody stools in dogs and cats.