Associated Press WASHINGTON — The dog hopped on three legs, pain from bone cancer so bad that he wouldn't let his afflicted fourth paw touch the floor. His owner was bracing for euthanasia when scientists offered a novel experiment: They injected a fiery sap from a Moroccan plant into Scooter's spinal column — and the dog frolicked on all fours again for several months. The chemical destroyed nerve cells that sensed pain from Scooter's cancer, not helping the tumor but apparently making him no longer really feel it. The dramatic effect in dogs has researchers from the National Institutes of...