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.
Many dog owners believe that any yellow or green vomit is necessarily bile, but this is not true. Food coloring in pet food can alter the color of your dog's vomit, and vomit consisting mostly of water may look like bile. Whenever your dog vomits, it's a good idea to withhold food until the vomiting stops. This gives your dog's system time to clear out the source of the problem.