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.
Exposure to toxins or poisons may cause a dog to vomit blood. In particular, rat poison is a cause of unexplained bleeding and can show up as a dog vomiting blood, often also accompanied by dark tarry stools and bleeding from other areas such as nosebleeds and rectal bleeding.