From FierceAnimalHealth: A compound called resiniferatoxin (RTX), which is derived from a cactuslike plant commonly found in Morocco, has long been pursued as a potential way to treat pain without dangerous opiates. RTX, in fact, is now in a Phase I/II study at the National Institutes of Health to treat intractable pain in people with end-stage cancer. But early trials in pet dogs have shown the toxin to be effective in relieving pain from canine bone cancer and osteoarthritis, too, and now ARK Animal Health, a subsidiary of Sorrento Therapeutics, has received encouragement from the FDA to pursue the compound for veterinary use. Read more here.