Mix barley grass capsule powder into your old dog's food (barley grass is cheaper than wheat grass). Within barley grass (& in most fruit seeds, except citrus) is Amygdalin (vitamin B17) which controls swelling, stabilizes blood pressure, kills errant healing cells (malignant growth), and deadens pain with its natural analgesic benzaldehyde. All B vitamins are water soluble therefore all B vitamins have no known toxicity. Never take B17 on an empty stomach.